Updated on 11th July 2001
A Handbrake under the dashboard
The original Mk I GT40s kept
their handbrakes in about the same
location as the glove box on most
cars: under the left hand side of the
dashboard. The 'tunnel' between
the seats had a curved top, much
like the transmission tunnel in older
rear drive cars, but narrower. By
contrast, most replicas have a
flat-topped tunnel with the
handbrake sitting on top of it in the
conventional position between the seats.
Although I am not fanatical about originality, I wanted my car to be a reasonable replica in the cockpit I also just liked the arrangement in the original cars. So the handbrake had to go under the dash. This was not a trivial job for two reasons. Firstly, the handbrake mounting has to take high loads. The driver may heave on the lever, and the mechanism gives a lot of mechanical advantage, so loads in the structure around the handbrake could easily reach 500 or 1000 Ibs. Secondly, the linkage would have to goaround three corners before it had a straight pull on the handbrake cables coming through the firewall. I decided to use an open cable running over pulleys. The first job was to fabricate a sub frame which would hold the handbrake in the correct location and provide mounting points for the pulleys. I had bought a cheap(ish) MIG welder and taught myself to use it I was confident enough to weld up a sub frame, but I did not want to start welding things to my precious chassis: so the sub frame would have to bolt in without having to drill big holes in the chassis (and thus weakening it). The basic shape of the sub frame is shown in the photographs. The location is quite critical (low enough to clear the dash without scraping your knuckles, but high enough to clear the passengers knees and keep the sub frame hidden from view), so make a mock-up from scrap wood and masking tape, and check it with the dash moulding in place. When you get to the metal, measure twice and cut once. I used 1" square steel box section. The plan was to run the handbrake cable down the centre of the box sections, so that all the serious loads would be taken by the sub frame members in compression, so I made cut-outs for pulleys etc before finally welding up. The handbrake itself was from a Triumph Herald. There was nothing special about this choice, but it was about the right size and looked the part (1960's - not 1950's chrome or 1980's Cortina). No doubt someone in the Club knows where the handbrake on the original cars came from. The mounting brackets were made up from angle iron welded and bolted to the sub frame. The all-important pulleys were a problem. They had to be large diameter (to avoid damaging the cable by continually forcing it around a tight radius), and they had to be strong enough to cope with the loads, and durable enough to go on coping year in and year out. I eventually used pulleys from the flap system of a light aircraft smaller Cessnas and Pipers use cables for both the main flight controls and the flaps, but the flap cables are larger at l/8" diameter. In some light aircraft (e.g. Cessna 180 or 285), the flap system is operated in much the same way as a handbrake, by heaving on a socking great lever. Good second hand flap pulleys are sometimes available from aircraft that have been written off. A friend in the industry managed to find me three without robbing his employees stock No doubt they would be available new, but I have no idea of price. The pulleys were mounted on brackets running across the corners of the sub frame (see drawing).
The only other critical item was the sub frame mounting next to the last pulley at the bottom of the front bulkhead where the handbrake cable emerged to run back to the rear bulkhead. At this point, the tension on the handbrake cable would be doing it's best to tear the sub frame out. The Tornado chassis has a substantial steel plate welded in here (supporting the driver and front passenger's heels). A lug was welded to the foot of the sub frame, and this lug was bolted to the steel plate.
the sub frame was later modified so that it doubled as a servo mount and tripled as a heater mount, painted and installed. The finished job (cable by Speedy cables) seems to work well, but the jury is still out on it as the car has not been MOT'd and only time will tell whether the whole set-up will hold up under the years of use. If I were doing it again, I might experiment with bell-cranks, rods and rod-end bearings (Rose joints) instead of the pulleys. I might also re-examine the idea of putting the servos under the dash. It's a neat installation, but access is difficult and it may become a maintenance problem.
It has been said by all on the trip and by several in print that the video of the club trip to tour France and
attend the 24 hours endurance race at Le Mans in 1996 was much more than the usual holiday record that
usually bores even those who are featured in the video within a short time. I can certainly say that I was
completely entertained throughout the 90 minutes and it would appear that several others were impressed
sufficiently to put their thoughts into print. I reproduce the text of one such member below as proof. If
you haven't yet ordered your copy from Ron Farmer please do so now and we may be able to persuade
him to record more of our adventures.
Thanks for prompt service sending me the "Le Mans 96" video - what a trip you all had !. Having read the articles in Fortyfication it was great to see it visually which brings me to the video, I really wasn't expecting something so professional !. Very well done. You know you watched something that kept you interested when the end of the video comes and 1 hours 30 minutes seemed like only a few minutes. I noticed you managed to keep things in focus during a few "Party sessions" - that's REAL commitment Ron !! Keep up the good work. Thanks again. Greg Dollimore. (New Zealand).
The 1996 Le Mans trip video is available from Ron Farmer at Three Gables, Woolfardisworthy, Bideford. North Devon. EX39 5PZ United Kingdom At £20 including postage and package. I can now also reveal that Ron has agreed to record our exploits on this years trip to France and the 24 hours at Le Mans, reserve your copy now.
Not not just any old portrait but a superb drawing of the GT40 and not just any old GT40 but the best
one in the world, mine of course. Well that was what father Christmas brought me and as you might have
gathered I am more than a little chuffed with it. The artist is Brian Sapsford who has been a member of
our club for some time now and is building a GT40 at the present time. Brian has produced a brilliant
colour drawing of my car and if you would like your pride and joy recorded in this unique way contact
Brian Sapsford Tel : (44) (0)1252 653320
This is a full colour print which has been produced to commemorate Jacky Ickx win at the Spa-
Francorchamps 1000Km race in 1968. It is a Limited Edition print of 250 and has been prepared and is
available from:- Philippe Poncelet. Fax No: (Belgium) 32 4 344 11 91
The price £15 inc. P&P;.
or am I dreaming
So there I was flicking through Exchange and Mart, as you do, when my eyes alight on "GT40 Part built Project £3,000". Two weeks later on a rented trailer I drag home an early KVA chassis, a set of Dax MK1 panels, together with windscreen, a set of Halibrands plus tyres and SAAB turbo engine/box You see SAAB engines sat over and in front of, the gearbox in the early 80's - useless weight distribution at the front of a SAAB 900, but great in the back of a forty. Sadly, it only has fifty percent of the cylinders I require, so it had to go. When it was put in, the guy basically cut off the front end of the SAAB and welded it straight onto the back of the KVA. Engine/box removed, I decided to leave the rest as it was. The double wishbone suspension looked solid and well sorted. Better still, those SAAB front discs and callipers looked meaty enough for the rear of the Forty and had the advantage of being operable from the handbrake too! A quick nip round a couple of scrap yards and I had a reasonable Cortina front cross member and some Granada uprights with vented discs. The discs had to be replaced all round, callipers rebuilt and some machining work done (convert SAAB 4 stud hubs to Ford 5 stud) for the Halibrands. Anyway for £420 she now proudly sits on her own 4 wheels. Having ripped out the 2.0 litre turbo, I had a big space waiting to be filled. In the back of "Which Kit" was an ad, which led to a Ford 351 Cleveland engine, 4v heads, 4-bolt mains and all recently rebuilt. Oil pressure looked good, it sounded sweet so £750 later, it was ripped out of its Mach 1 Mustang and on it's way to Gosport with me. A few worrying phone calls - as it dawned on me that 351 small blocks are bigger than 302 small blocks. Happily Robin Sundt assured me that it was a squeeze, but he had managed the same feat in his KVA. So that's where I'm at, to date. As my garage has no electricity or electric light and it's turning dark I thought I'd sit down and estimate the cost of the project (it's okay, the wife is out of the house !!), here goes;
|Steering wheel and column||£100|
|Handbrake, pedal assy and brake lines||£100|
|Springs and shock absorbers||£500|
|Fuel tanks, pumps, filler caps etc||£500|
|Radiators, plumbing, cooling fans||£300|
|Oil cooler and plumbing||£150|
|Exhaust manifold and pipes||£500|
|Gearbox, flywheel, mating plate etc||£750|
|Machining drive shafts||£100|
|Various chassis wclding jobs||£200|
|Wiper + motor, horns, ancillaries||£100|
|Lights, instruments, loom||£300|
|Locks, handles, window perspex etc||£300|
|Trim and carpets||£100|
A total estimate of £4,000. With the other bits I've
picked up along the way, I've currently spent another
£4,300, Total on the road price, £8,300 without paint
Even if my estimates are a little out , the Forty should hit
the streets a little under £10,000 including paint. Okay,
so the engine won't be race tuned and the suspension /
steering will only be good instead of awesome. It will
however look coolashaka, sound wicked and be grreeatt
fun! I hope to have the car on the road in time for the Le
Mans this year, if not I'11 have to go in the other
shopping trolley my Ram Jaguar 'D' type -Dorothya- total cost to build her ? You guessed it, £10,000.
by Brian Coombs
One has to admit multiple carburettor setups, apart from
improving performance really look the business dare one
say that it is the latter aspect that is of prime importance.
Such systems have long been available for V8 users,
however, those of us with the Ford V6 Cologne engine
had to make do with a single Weber or similar. That is,
until a company called Torque Developments introduced
a triple carburettor conversion for this engine in 1993.
So at long last I could dump my single 38DCAS for a
multiple Weber arrangement. Torque Developments
system package comprises an independent - runner inlet
manifold in aluminium alloy [LM25], 3 x 42 DCNF
Weber carburettors and an Electromotive direct fire
ignition unit [see newsletter No. 20]. A phone call, followed by a visit to TD in December '93 and a
detailed equipment spec was agreed and an order placed for delivery in March '94. The Electromotive
HPV-1 ignition system
was adopted by TD since the inlet manifold design did not allow a conventional distributor to be fitted due
to lack of clearance. The HPV-1 system is an electronic distributor that fires the plugs directly from a
bank of coils [3 for a V6] without the need for a mechanical distributor. Two major components make up
the system: the direct fire coils and control module and a toothed pickup wheel/magnetic sensor assembly.
Three knobs on the control module allow the ignition advance to be set at 1000, 3000 and 8000 RPM,
while a forth knob gives control of a soft - rev limiter, which retards the advance to TDC at the set RPM
for effective engine speed limiting without ignition cut off. Torque Developments standard package uses a
crankshaft mounted pickup wheel and a magnetic sensor bracketed to the crankcase, the fitting of which
would have required removal of the engine. As far as I was concerned this was an absolute No, No. O.K.
so I am a wimp, but I just did not want the aggro associated with removing the engine. So what to do?
Well the answer was to use Electromotive's self- contained pickup wheel/magnetic sensor designed to fit
onto the distributor shaft, once the internals have been removed. But how come, I hear you ask, since the
distributor cannot be fitted! Simple. After discussing the situation with TD a special angled drive was
designed and developed which comprised the lower section of the mechanical distributor [helical gear
drive from camshaft], a heavy duty universal joint and an extension shaft [see fig 2].
Holidays and a Le Mans trip delayed work on the system, but once started the installation was quite straight forward and is shown in figures 1,2 and 3. Once the installation was complete the first operation was to set the required ignition advance curve. A point to be considered in setting the ignition on a modified engine [mine had been bored/stroked to 3.1 Itr., fitted with a fast road camshaft and larger valves is that it will tend to be more efficient at high and less efficient at low RPM. High overlap camshafts reduce volumetric efficiency at low revs and therefore require more ignition advance at these speeds to compensate. Also larger choke carburettors tend to reduce the gas velocities through the ports at low revs so that the engine burns fuel more slowly, which again requires more ignition advance around idle speed to overcome this effect. The ignition advance must also be matched to the engine's requirements over the full rev range. A standard mechanical distributor can be rotated to give more advance at high RPM for optimum power, but this does not necessarily match the engine's low speed needs. The advantage of the Electromotive system is the ease with which the advance curve can be adjusted independently at low and high revs [1000, 3000 and 8000] to optimise engine performance. The advance at 1000 RPM had to be set with cylinder No 1 at TDC, - Simple, rotate the engine to TDC using the pulley timing notch and crankcase timing plate, set the pickup wheel/magnetic sensor and dial in the required ignition advance [16 degrees BTDC3 on the HPV-1 control module. The next step was to dial in the advance requirements at 3000 [35 degrees BTDC] and 8000 [40 degrees BTDC] RPM. With the ignition advance curve set it was time to fire up the engine. I did and it was just appalling - carbs sneezing under light to moderate throttle, occasional dull popping from the exhaust and a severe flat spot during the progression phase. Things were a little better above 2000 RPM, so by holding the throttle open at 2000 RPM the carb balance could be checked and initial adjustments made. But what was the problem at idle and during the progression stage?. informed opinion and the Weber carb tuning books by Braden and Passini gave the answer as mixture too lean and/or timing not advanced enough. I knew (!) The timing was OK, so it had to be the carbs. However inspection of the plugs revealed that they were sooty and wet; in retrospect this should have started the warning bells ringing but it didn't. Since the idling jet deals with progression as well, it is usually selected for the latter function and the mixture screws meter the idling emulsion. Over the next several weeks various idle jets and mixture settings were investigated in an attempt to overcome the idling and progression phase problem, all to no avail. At this point and in some desperation, the carbs were removed and their spec. checked - they were found to be choked and jetted for an Aston Martin 5 litre V8! This situation was discussed with Torque Developments and, together with base line jettings suggested in Braden, a number of changes were made. The major ones were a reduction in the choke size from 36mm to 34mm [I was more interested in bottom end and mid- range drivability than top end performance], a reduction in auxiliary Venturi size from 4.5mm to 3.5mm to bring in the main system earlier and a change in emulsion tube from F39 to F25. Problem solved, or was itl No was the emphatic answer. The symptoms were still essentially the same; the penny still didn't drop. It was a good job that I did not have a length of rope handy at this point. So what to do now? Well I was at such a low ebb that I decided to revert to the original single carb. However, Ray Jones of TD said he would come up and see what he could do to sort things out [a 600-mile round trip]. This he did, arriving on a cold and rainy Saturday morning at 8.30am. The first checks Ray carried out were to ensure that the float levels and fuel pressure [engine running] were correct. A minor change to one float level was required, but otherwise everything was OK. Next was a check on the ignition timing using a timing strobe; I knew this would be OK. Wrong!!! The indicated ignition advance at idle was Zero degrees BTDC!! Don't ask me how I managed to build in a mechanical retardation which effectively cancelled out the advance dialled in on the Electromotive unit. My only excuse is that I did not have a timing strobe ( I have now) to check, as per the manual, whether or not there were any mechanical errors in the alignment of the pickup wheel/sensor with No 1 piston at TDC. Advancing the 1OOO RPM ignition setting on the HPV-1 module to giw an actual value of 16 degrees BTDC resulted in instant elimination of all the previous problems and produced a smooth throttle response from idle and up through the progression phase to max RPM. Ray then balanced the carbs and suggested a short road test. Well I must say that I was less than enthusiastic about that: I don't usually take the car out in the sort of weather we were experiencing! However, we did and it confirmed the no load response, the engine pulled smoothly and sounded just great. Cod was in his heaven and all was well with the world.
The current jettings etc are:-
|Main jet||1.45mm [will probably end up at 1.35]|
Final calibration is to be carried out on TD's rolling road sometime in 1995. Now, the eagle eyed among
you will have noted that the carbs are mounted "the wrong way round". Accepted convention is that the
float chamber should be ahead of the chokes relative to the direction of travel. This is to prevent leaning
out under acceleration and rich stalls under braking. Well I can only say that I have not, to date,
experienced any such problems, perhaps because my driving style does not involve harsh acceleration or
braking! should the need arise they can be fitted the correct way round, but the throttle and choke
linkages become more complicated. One problem currently being experienced is that when the engine
[hot] remains stopped for some time, the fuel in the float chamber expands and dribbles out of the pump
jets and into the chokes where it pools on the throttle plates. This can cause the odd restart difficulty,
which could become a major problem on a hot day. Has anyone out there experienced this and if so how
did you overcome it? So was it all worth the effort not to mention, dosh? The short answer, now that it is
up and running, is Yes. Even if there were no improvements in performance the triple carburettors
enhance the car's appearance which, although we don't always admit it, is important. For those members
who may be interested in the conversion the Boys to talk to at Torque Developments are Mark and Ray
When using any Glass Reinforced Fibre (GRP) one thing that should be remembered is that the resin that
you will be using is set chemically uslng a hardener (catalyst) and will only set correctly if the correct
proportions of resin and hardener are used. i.e. 2% [two percent] hardener only. Do not be tempted to
change the proportions to assist with speed of setting or use in cold conditions, it does not work. It will
also make the resultant GRP weak and in the worst cases can cause it to crumble and break up or not set
at all. The resin/hardener mix once mixed in the correct proportions will set. Temperature has a great deal
to do with how long it takes for the GRP to set and in general you should aim to work with resin in a
10-25 degrees Celsius environment. Hotter than this is OK but below 10 degrees the set will take a long
time during which the work is vulnerable. In very low temperatures the resin will not set correctly. Several
types of glass fibre are available but for most repairs or additions chopped strand mat is the one to use as
this provides good all round strength. The woven material provides a more flexible structure and is useful
for some constructions but is in general used on specialist structures. Surface tissue is used to help
provide a smooth surface to sections of GRP that are exposed in construction or to form the top surface
of the construction. When impregnating the glass fibre with the resin/hardener mix it is essential that you
thoroughly wet the construction and get all air bubbles out of the glass fibre strands and the mat, these air
bubbles will reduce the strength of the final assembly and if a finished surface is required the air bubbles
will form pits making a very undesirable finish. Use a stiff bristle brush and work the resin well into the
glass fibre mat. Disked rollers are available to help flatten out and get the resin to penetrate into the glass
fibre mat but I usually always finish off with a brush as that seems to produce the best results. Several
different weight (thickness) glass fibre mats are available and for general work and repairs on car
body shells I usually find the 450gm material to be best suited. Inevitably we have to resort to fitting metal
brackets etc. to the GRP body shell but in general and on the basis that all but precious metals corrode you
should avoid the inclusion of metal if possible. If you are forced to incorporate metal, then you must
ensure that you provide adequate keying for the GRP and it is best to provide a large base to any
appendage with numerous holes through which the GRP will bond. Use chopped strand mat over the
whole metal base and extend the mat well beyond the edges of the base and of course well wet with resin
and exclude all air bubbles. If you have any cracks or holes to fill or gaps to close up then the material to
use is resin filler. This is resin/hardener mixed with a filler powder. Two types of filler powder is available
the first and one generally used is a fine powder which is based on Calcium Carbonate and the other is a
material which is microscopic air filled balls. This latter material is very light weight but but does not
provide as good a finish as the first. The filler powder is added to the resin/hardener mix and stirred in
until a suitable putty like consistency is achieved. Scratch up the area to which you are adding the filler so
that it provides a good key, although on surfaces other than Gelcoat finish it will produce a reasonable
key by itself as the surface is usually fairly uneven. If you are building up an edge to close a gap then you
should either provide a mat GRP backing or thicken the filler and extend it behind the existing material so
as to provide sufficient strength to the new edge. This filler material can be filed roughly to shape and then
sanded and smoothed to final shape as required. The other main use of GRP when building the GT40 is in
sheet form for inner wings, fresh air ducts etc. This material can be easily made using a sheet of glass
which should be thoroughly cleaned and polished with a dry cloth. [use a household spray wax or
furniture polish on the glass to assist separation of GRP from the glass. but remember that the smooth
side of the GRP has wax on it, so don't put wax where you may wish to bond]. Chopped strand mat glass
fibre is then laid onto this surface and thoroughly wetted with resin/hardener mix and allowed to set.
When the resin has got to the green or rubbery state the sheet can be lifted off the glass to release the
bond and then replaced onto the glass and allowed to set hard. The resultant sheeting can be easily cut
with metal shears and bent into most any shape. Sellotape can be used to hold sections of this sheeting in
the desired shape and then it can be joined with small piece of glass fibre and resin. When this is set the
Sellotape can be removed and the structure glassed over with further material to thicken and strengthen
the final result.
Having spent many years building, modifying and generally fiddling with a GTD 40, I've come across tips
and solutions to many problems, as most people have. However, as all cars are different, I would like to
share my experiences.
I'm using a 351 Cleveland engine, which, as KEN SAUNDERS has mentioned in a previous article, needs a lot of cutting grinding and welding of the chassis to fit properly (especially if it is fitted as low as possible), but the biggest problem, apart from HUDDART ENGINES, has been the inlet manifold, as no-one makes one for downdraught DELORTO'S. I've had to make my own, so if you are going the same route, either use WEBBER IDA's, for which a manifold is available trom Fast Freddys, or be prepared to fabricate one.
The Cleveland's heads are completely different to the 302/351 Windsor engines (excluding BOSS versions), but they can, with some small mods, be fitted to the small blocks as they are a very high flowing, big valve head, remembering of course the different inlet and exhaust manifolds needed.
With powerful engines come the need for better brakes. The standard Granada Scorpio based brakes are ok for the road, but are no use for any type of track work, Many people have changed to AP Racing or similar discs and calipers which are a tremendous improvement. However they are expensive and require a lot of maintenance.
Personally, I dont like using servos, I've used them in the past, but a properly designed system without them can have the same braking effort with more feel (important for those "OH S***" moments). Whether you use the latest dinner plate discs and multi piston racing callipers or mass produced items, a properly thought out system is needed to bring out their best.
The standard GTD set for instance uses a brake pedal ratio of around 2.5/3.0 : 1 because of the twin servo assistance, however, if servos are not used, the pedal ratio of at least 5:1 is needed, so a lot of cutting and welding is required, if a balance bar is to be used (very useful if tyre or pad changes are made later), the procedure is made more complicated. Another method is to use an adjustable proportioning valve incorporated into the rear brake system, you can even combine the two, depending on what the car will be used for. It's Possible to calculate the brake torque, pedal effort etc, needed or given for any particular system using simple mathematics. As an example, I will use the calculations for my braking system:-
Front Discs = 10.75" dia ventilated. (Jaguar XJS)
Front Callipers = 4 pot, 44mm dia pistons. (Rover SD1)
Rear Discs = solid 11" dia. (Jaguar E type front)
Rear- Callipers - 4 pot 38mm dia pistons. (Austin Princess)
The following information and calculations were obtained with reference to the Brake Handbook, by Fred Puhn.
I = wheelbase (95")
Rft = Rolling Radius of Front Tyre ( 12")
Rrt = Rolling Radius of Rear Tyre ( 12" )
FT = Vertical Friction Force On Both Front Tyres ( 1328 )
FR = Vertical Friction Force On Both Rear Tyres ( 1172 )
Weight Of Car = 2500 Ibs
The following information is difficult to obtain so a typical or approximate value must be used -
N = Coefficient of Friction of Tyres = .75
dm = Maximum Deceleration = .75 G
Ycg = Height of Centre o~ Cravity = 21"
N1 = Coeficient of Friction of Pads = .3
|Front Brake Torque =||N x FF x Rft =||5976 "/lbs|
|Rear Rrake Torque =||N x FR x Rrt =||5274 "/lbs|
Front Calliper Piston Area = 8.547 sq"
Rear Calliper Piston Area = 7.065 sq"
Front Max Hyd Pressure=
|N1 x Total Calliper Piston Area x Effective Brake Radius =||460.5 psi|
Rear Max Hyd Pressure = 553 psi
Now, the maximum brake torque both front and rear is known also the hydraulic pressure is known and the calliper must be able to operate safely at these pressures.
Next, we have to determine -
1/ The pedal ratio,
2/ Master cylinder size and pressure.
I'm using a pedal ratio of 5:1, it's a typical starting ratio and because of the pedal box design and foot well constraints it was the maximum practical ratio possible.
Note, if a balance bar is used the pedal effort is effectively halved to each master cylinder.
Pedal Pressure ( typ )= 75 lbs
|Force on Cylinder Piston =||75 x 5 =||187.5 lbs|
|Front, Master Cylinder Piston area =||187.5 =||0.427 sq"|
Nearest Available Cylinder Diameter = .70" to .75"
Rear Master Cylinder Piston Area = 0.30 sq"
Nearest Available Cylinder Diameter = 0.625"
I am using a .70 front cylinder, a .625" rear cyiinder and a .625" cylinder for the hydraulic handbrake (I also have a separate mechanical handbrake system using cables and Willwood mechanical callipers).
To help keep the cockpit as cool as possible and also to improve aerodynamics, I have installed the radiator further forward and panelled behind it to form a smooth air flow path from the radiator to the twin nostril outlets.
To improve access to the rear of the dashboard if needed, I cut the dash into top and bottom halves. I fitted brackets to the rcar side of thc mouldings so the pieces can be screwed together. The bottom half is painted and the top half is trimmed in leather cloth.
All I have to do now is to fit the sunroof, furry dice, tow bar and the car is complete, sort of.
[Dave explained to me how to find out the Brake Pedal Pressure needed for the above calculations, without going to the expense of an inline pressure gauge.]
1. Put a brick on the brake pedal.
2. Place your bathroom scales on the brick.
3. Stick your foot on the scale and press, then read off the pedal pressure.
[ It's easy when you know how! ]
Richard Craven in the last newsletter laments the lack of reports from the Coy's Festival this year. Well,
we were there, and as usual enjoyed an excellent two days of cars, cars and more cars, including not only
an impressive line-up of GT 40s (original and otherwise) but also GTD's new R42. As I've said before,
this particular meet at Silverstone is always worth a visit. Unfortunately, my memory of the meeting itself
has been eclipsed by the experience of driving back North up the M1 through one of the heaviest (and
longest!) rain-storms I
have ever experienced on the road. Nietsche said "What doesn't kill you makes you stronger", so having
survived I feel it only right to share with you some of my (and the car's) added strengths as a result! First
and clutch foremost, you will know that with wide tyres you aquaplane easily. And how! I hadn't realised
as we hit the storm how much surface water there was on the road, and at 70 mph under those conditions
the GT40 turns "power-boat extraordinaire" but without any hint of directional stability. By some
incredible stroke of luck (should I say skilful driving here?) control was fairly quickly re-established
without contact with any vehicles in the other three lanes, but my heart rate took much longer to subside.
Believe me, reading about aquaplaning is nothing like actually experiencing it (especially on the M1). Be
warned! The rain itself lasted for 30 minutes plus, and was torrential. Because of its low stance, in a GT40
you proceed in twice the rain of anyone else; the rain coming down, and the same amount again bouncing
back up off the road. This essentially means that you drive without seeing out of the windows (or IFR, as
pilots say); all I could see in front of me was the merest hint of a white blur of the line marking the
emergency lane, and the drumming of its rumble bumps telling me when I strayed over it. Now I did have
my wiper, but even going double speed it couldn't clear the screen, and eventually the motor started to
wrench itself off its mounting. The increasingly drunken movement of its arm persuaded me to use it only
intermittently (extremely intermittently), and the next day inspected it closely. If you do the same, you will
find (probably) that it is only attached by its output shaft and one small mounting bolt. What I have now
done is to attach it more securely by fixing a strut from one of the extra holes provided in the assembly
down to the front bulkhead, as shown in the photo. [the strut is of round tube with flattened ends drilled
for bolts. it is secured to the front bulkhead between the and pedals.] This makes a more satisfactory
installation for what is a powerful, heavy and torquey item. Incidentally, the other thing I checked was the
wing enclosures, having seen water (source unclear) dripping onto the garage floor. I removed one front
light access panel and looked in. No water there! Until I looked closer. There was water, lots of water,
gallons of water! Right up to the access panel aperture! When I had drilled drain holes in the bottom of all
four wing enclosures the floor was awash. So it's probably worth doing the same to your car if you haven't
already done so. I hope the above account may help you and your car to cope with heavy rain that much
better in the future. Suffice it to say, the car leaked like a sieve, but the engine never dropped a beat, and
we emerged from the other side of the storm soaked but at least reliably mobile for the last 100 miles of
the journey! Talking of struts, have also
secured the free edge of the dashboard to the left of the steering column in a similar fashion (see photo). It
does give the dash a more solid feel when you bang it with your knee, but more importantly it stops it
vibrating so freely and shaking out all the instruments and their electrical connections! Finally, those of
you with the vinyl replica Corbeau seats may find that with use the seat and back squabs start to come
adrift from upholstered frame. One way preventing this is to apply beads of Sikaflex (black) adhesive in
the appropriate areas. This holds the vinyl together very securely, stopping that 'falling apart' look, and
having the merit of needing none of the skill of an upholsterer. Do be sure that the adhesive has
completely dried before using the seat; Sikaflex is merciless when you show it no respect! Before I sign
off this communication from the far North, can I thank Ken Saunders for all his recent articles? Not only
for their excellent technical merit, but most of all, Ken, because stories of unfortunate oversights from an
expert such as yourself make me feel that much less of a wally when I think back to forgetting the oil and
seizing my gearbox!!
During one of my weaker? moments while building my 40 and there have been many, from minor ones
like threading 9 feet of oil pipeline through the car only to find that I'd got the wrong end at the back, to
major ones like dropping a piece of plastic down the distributor hole into my newly rebuilt engine - I
asked myself things like 'why do I bother "or" how did I get into this'. I thought it would be interesting to
know how other people ended up building complicated things as the GT40 replica undoubtedly is, and
decided to put my story down on paper. Who knows it could form the start of a mini series with other
members relating their tales of how they slipped (or were willingly led) into automotive insanity. I suppose
l have always been interested in mechanical things. As a youngster l was keen to find out how things
worked and to that end my father's garage was full of toasters and irons that had been taken apart and
rebuilt, usually never to work again! However I do remember one iron that heated up so well it became an
excellent, if slightly lethal toaster. I built model kits. Remember the Jetex engine? For those who don't it
was a jet engine in the form of a small cylinder with a hole in the end which burnt solid fuel pellets. One of
these was fixed to the back of an Airfix Blower Bentley. I never saw the car or the engine again! My
home was at the bottom of a steep hill with a long sweeping bend half way down. Go-karts were built in
various forms using wood and pram wheels. The bend in the road proved too easy so in order to make life
more exciting (as if traveling up to 40 mph in a pram with no brakes wasn't exciting enough) we decided
to travel down the pavement on the apex side which, instead of a bend formed a sharp dog leg. Wonderful
stuff but don't ask me how I survived. Fitting a sail to the said trolley was another innovation and I reckon
I must have had one of the first 'sand' yachts. There were however several serious design faults in that the
sail was a)too big. b) fixed firmly in position. c) still had no brakes. This resulted in a contraption which
went very fast in whatever direction the wind was blowing and only stopped upon meeting an immovable
object ( usually a wall ). It was then impossible to push against the wind so I couldn't get it home.
Eventually my mind turned to motorised things and I passed my bike test on a 50cc Suzuki which I duly
dropped breaking my wrist and most of the plastic bits on the bike which seemed to be about 90% of it.
By this time I had discovered a certain journal. No forget Health and Efficiency. This was much
better-Exchange and Mart. You could buy almost anything in there and my mother approved. OK I might
build something that could kill me but at least my eyesight was safe, A firm called Pride and Clarke ran an
advert on the back page and sold bike bits at quite reasonable prices. Then I had this brilliant idea - I
would build a motor bike. I had wanted an Ariel Arrow (250cc monster in my parents eyes) and started to
buy parts every week with my meagre trainee's wages. My parents were certainly not keen but lodged no
real objections - they even agreed to let me use the garden shed as a mini workshop stipulating that
whatever I produced must have brakes! After all exploding toasters and white hot irons were still recent
memories and they knew it would never work. But work it certainly did and I even made a small profit
when I sold it - but only if you disregard the postage charges on all the parts. This then was the start. I
built a second Arrow from a œ5.00 wreck - much more sensible way of doing things and eventually
progressed onto cars. The first kit car was a Mini Marcos Mk 1, then a Mini Marcos Mk 4. I got involved
in the MG Owners Club and went through two Midgets, an MGB GT, three MG 'Y' type saloons and an
MGA. The MGA was sold unfinished because I was still building a Gentry TF replica (Triumph based)
and finishing one of the 'Y' types. I'd bitten of more than I could chew! In l981 Marcos started to produce
kits of the Coupe and I decided to build a 3 litre V6, something I had wanted in the seventies but just
couldn't afford. After this I built a Westfield just for something to do and sold it almost immediately. So
where in the scheme of things does the GT40 come you might ask. Well obviously I knew of the GT40's
Le Mans history and knew that someone produced a difficult to build kit with no instructions. Then I
managed to invite my son and myself to a GTD organised display at a Ford dealership in Chepstow. I was
certainly impressed by what I saw but the cost of the project was off putting to say the least. Here it
comes, you are all saying, the usual rubbish......saw the GT40, couldn't live without one, the car I had
always wanted, sold the wife and kids into slavery to afford it etc. etc. Well, sorry to disappoint you all
but at that point this was far from the truth. No, my decision to build a GT40 was borne purely out of a
desire to make some money. It was clear that well built examples were then selling for substantial amounts
and I worked out a cunning plan. It went something like 1) Re-mortgage the house to obtain funds 2) Buy
complete GTD kit 3) Build kit in about six months (well I didn't know!) 4) Sell car to Sumo wrestler for
huge profit 5) Build another one for me. Free!! Well fortunately for me the bottom fell out of the market
before I could put this stupid plan into action. By now I had been to Tornado cars, who were a lot closer
to home than GTD, and had been driven a short distance in a 40. There was no getting away from it, I
was getting hooked on the idea of the supercar image, huge v8 engine and that body shape. I'd never
really looked at the 40 before but it is just a fantastic shape and I knew that I wanted one. My wife knew
that she didn't. Eventually I placed an order with Andy at Tornado for a chassis/body kit in October l991.
My wife still wasn't keen and was making empty threats such as "if a GT40 arrives I leave" etc. I took
delivery of the kit a full year after placing the order. Living on my own was a new experience and
certainly had some advantages. I could spray the dash in one of the spare bedrooms and use all the other
empty rooms for storage! On a more serious note it did pose problems in the GT40 finance department
i.e. very little plus extra large mortgage leaves almost nothing for building kit cars. The project went into
hibernation for almost two years while I sold the Marcos(sob) and another Westfield which I had built
while waiting for the GT40 to arrive. They all had to go but, by arrangement, I managed to keep the 40.
Yeah!! Obviously specifications had to be changed. Out went the air conditioning, the leather seats, the
expensive wheels and all the other goodies that make building the car more straight forward. I drew up a
list of parts that I had to buy from Tornado and decided to get everything else when and where I could ...
and cheap. One interesting example of this was the wheels. I was at the Malvern Bits and Pieces
Autojumble and came across some O.Z. two piece wheels. Six for œ60. Bargain I thought. The outer rims
were all a bit bent but I knew that new outers would be needed to get the wheel size correct. I wasn't
worried. After getting said wheels home I put them on the back of the car and spun each one in order to
check that the back rims were true. The first one was obviously egg shaped. I wasn't worried there were
five more. The second was the same as the first one. I wasn't worried.......I was panic-stricken! As the
third wheel went on, the usual 'why do I bother? ' 'How did I get into this? ' could be heard. But with
considerably more than my usual luck all the remaining four wheels ran true. Phew!! Next to get some
rims. "Easy" says Ken. 'Racing Wheel Services' have got them. No they haven't. Neither has any of the
other ten agents I rang. It seems that O.Z. won't sell outer rims, only complete wheels. Thankfully Davey
Automotive came to my rescue and obtained rims to fit but not before yet another interesting twist. I was
about to leave when I was asked "Have you got the old rims off yet?'" Funny question I thought but
replied that no I hadn't done so yet. "OK, have fun then" he smiled. I left wondering what, apart from
coffee, he had in his mug. On arriving home I looked the thirty wheel bolts holding the rims together and
noticed they were splined heads. So that's what he meant. Didn't matter to me, I had a special splined
socket. My smug look turned into yet more dismay as I realised that O.Z. with typical Italian flair had
decided to make not only the wheels but the bolts as well. Normal splined bolts have twelve points. These
had ten! The man in the tool shop wasn't exactly rude to me, he just inferred that I couldn't count. I
assumed that ten spline sockets were not available (or even legal if he had his way). Undaunted I went
home and managed to extract one of the bolts. The nuts were the same but larger. I used these items as a
die and hammered a hollow bar onto them, tempered it and " hey presto " had my very own ten spline
sockets. After loosening and tightening 120 bolts I can safely say it worked. So at last I had a set of five
spoke wheels 8" front, 10" rears which after painting look great - at a bargain price.
I pulled on the rim of the wheel to check it was secure, settled back into the familiar eyelet covered seat
and fiddled nervously with the webbing of the full harness belt that I had just fastened. My eyes flicked
expertly across the gauges that had been lovingly inserted into the matt black dash panel. All looked well.
Inaudible to me over the sound of my own 302 engine I knew that the air would be filled with a crescendo
of noise, as the revs rose in twenty or so powerful motors, all waiting for the signal that would send the
pack rushing towards the first corner, I had qualified badly. The morning session had been wet and the
track seemed to be inviting me to try too hard. I didn't like the wet, I had decided. Stil1,I consoled myself
with the thought that ninth on the grid behind the likes of Porsche 917's, Lola T70's and a single Ferrari
P4 wasn't too bad for my first race. The track was dry now and the sun shone brightly through the steeply
raked windscreen of my 40, shrouding the view of the high tail of the T70 ahead of me in a haze.
Suddenly we were off! I had been planning the start and going over and over it in my mind. Not too many
revs, let the clutch out fully, but in the end it was just a touch of the 'Murray Walkers'......"Go Go Go!!
Fortunately I made a superb start which saw me rocketing up to fifth place and I tucked into the tow of a
Porsche 917 as we hurtled into the first corner. Safely around and I now had time to assess the situation.
In the lead was the superbly turned out B.R.G. Lola T70 that I had admired in the pits before the race.
Then a yellow 917 Porsche followed by a beautiful Ferrari P4, in red of course. The 917 was just ahead of
me in my GT40, the sun glinting off the silver grey stripe over the burgundy paintwork all of us pulling
steadily away from the rest of the field. Several laps had gone by and the order had not changed although
I had worked out that I could brake later into turn 7 than the 917 in front, " probably due to the powerful
vented Granada discs on the front" I mused, as I set myself up for the manoeuvre that l had planned. I
marvelled at the way the 40 was able to hold the inside line as I powered out of the corner onto the finish
straight in 4th place. I had set the car up precisely as it had said in the build manual and with the part worn
255 MXX's on the back, to say nothing of my bargain OZ Racing wheels, it was an unbeatable
combination! I was now on the tail of one of Enzo's finest - and catching it! However I was soon to be
unexpectedly in front as the P4's engine suddenly exploded in a plume of steam and flames and I reckon
that I was lucky to avoid the slewing car, due of course to superb reflexes that even our Damon would be
envious of!! We were into back markers now but still in front of me and in line astern were the T70 and
917. The latter had been gnawing away at the T70's slim lead and on turn 5 the Porsche drivers
desperation got the better of him. I had seen it coming and held back slightly. The Porsche, attempting to
dive up the inside of the Lola locked everything up and ended up in the gravel, the driver hammering on
the steering wheel in annoyance with himself. But this was good news for me and using all my skill I was
able to glue myself onto the tail of the T70, which due to the Porsche antics had been slowed slightly. As
we passed the pits I didn't need to be told that I was in second place. But this was the last lap and
knowing how well the tyres were gripping decided to make an all or nothing attempt to pass on the last
corner. My only real fear was how well the Mini derived door locks would cope with the fantastic 'G'
forces being developed, which were already pulling my face into features best suited to some hideous
gargoyle. The last thing I needed was for the door to fly open as I hurtled into the last left hander. We
were there. This was it, it was now or never. I hauled on the wheel and buried the throttle -- then it
happened -- the drivers door flew open and I heard the faint cry of a marshals voice saying. "How long
does it take to put a steering wheel on? You've been out here for ages! Want a coffee?" The 'marshal' was
Gail! Dammit, happens every time I sit in it, the brain cell wanders. Did I tell you about the time my 40
clocked 300 mph down the Mulsanne straight? Sorry, there I go again!! Now where was I? Oh yes,
steering wheels I had originally fitted the ubiquitous Mountney l3" wheel but was less than happy with the
fact that it was dished and too small with too thick a rim. I had always thought that a wheel nearer to the
original would not only look better but give a better driving position as well. Whilst rummaging through
the shed I came across a leather sports wheel from a Capri that I had left over from a previous project.
This was pretty much what I was looking for except that it was crimped onto a boss that if used, would
probably have put the steering wheel somewhere in the engine bay! Upon inspection I decided that I could
angle grind the wheel off the boss and drill it to fit the Astrali boss. Now angle grinders are really useful
tools but you have to be careful and wear proper goggles etc. The receptionist at the local eye hospital
was very understanding and proceeded to ask my name and occupation. "Optician", I mumbled almost
inaudibly, so that the packed waiting room wouldn't hear. "Did you say OPTICIAN', she appeared to
scream, whilst choking back a smile."I've got him", shouted her accomplice from the back of the room.
"He's been here twice before!""Thanks." I thought, and vowed to kill the next person that even looked
happy! From these answers you can probably guess the questions. The conversation went somewhat
tersely like this.....; "I've got some metal in my right eye." "I was using an angle grinder." "Yes very
dangerous." "I know you do." "I was" "Yes they do fit well." "Well it must have got in through a
ventilation hole." "Yes it could, now how long will I have to wait?" A few hours later and I'm back in the
garage, complete with eye patch. Without binocular vision judging distances is a bit difficult. My next
trick is to miss the steering wheel boss and whack my thumb with a lump hammer! In between the
throbbing I was of course querying why I bothered, how I got into it and I think an "I don't believe it". got
in on the act as well! I don't give up easily though and a few minutes later I'm back ---- eye patch, big
bandaged thumb and my one good eye staring maniacally as I attack the poor unsuspecting wheel with an
even bigger lump hammer! This time it yields and I decide to call it a day while I've got some bits still
working! I eventually did manage to mount the wheel onto the Astrali boss and I'm very pleased with the
result. Fitting it to the car, I pulled on the rim of the wheel to check it was secure, settled back
into............but hang on, isn't this where we came in?!!
We are all aware of the very average performance of the standard brakes on the GT40 replica. The 10" diameter narrow vented discs with twin pot callipers of the Ford Granada that are used on the front are OK for normal road usage but soon fade if used in anger. The 10" diameter solid Granada Scorpio discs or even the 10" diameter vented RS discs with the single pot callipers used on the rear are also a bit on the small size for anything other than a quite Sunday drive. The answer is of course to uprate the brakes and as was detailed in the previous issue of Fortyfication one way is to buy the kit from Wilwood. The other option that is open is to go for the AP Racing brakes and a kit of parts is now available to uprate the front brakes to 13" wide ventilated discs with four pot callipers. The kit includes the discs, mounting bells, callipers, calliper mounting brackets, all the bolts required and a set of Mintex 1155 pads. AP Racing will not supply you directly but I have found a company who are local to AP Racing and who can supply these kits as well as most other AP Racing parts including special parts fairly quickly. The company is Tech-Craft Motorsports. 12 Dongan Road, Cape Industrial Estate. Warwick. CV34 4JW Tel : 01926 403721 and the guys to chat to are Roy Lane or his son Anthony. The kit is available at £1150. If you wish to go one better they offer Mintex 1155 pads for the rear callipers or the new Carbon Metalic pads for more serious work. I use these and they are equally as good on the road as on the track. If you want to go even further you can fit the same four pot callipers and discs to the rear wheels although you will have to look at the calliper mounting a little more than you do on the front. I have a four pot system all around and the difference is really amazing. If you fit four pot callipers on the rear you will also have to do something about the hand brake as these callipers do not have a cable operation facility. The easiest way to overcome this is to fit Go Kart type cable operated callipers on the opposite side of the disc. This will need some special mounting brackets but they are fairly simple and should be easily made or obtained. The other alternative is to fit a hydraulic handbrake, however this does not fully fulfil the road legal requirements which states that you must have a means of mechanically locking the wheels. Some of the rally cars get around this by having a pin that they drop through the transmission to lock it up, however this is perhaps not acceptable in our case. I have a hydraulic handbrake but I have a sympathetic MOT man as well !!.
The other eternal problem is of course the clutch, as soon as you give it a bit of welly or uprate the engine even slightly the d** thing slips. The standard clutch is the Renault and is fairly conventional in construction. Unfortunately this type of construction is not compatible with the sort of power that we get from the Ford 302. Several different clutches have been tried by members with varying degrees of success. You can of course go the multiplate route however these are a bit expensive with the bare materials costing around £700. You will then have the problem of fitting it to the flywheel as is won't fit the standard drillings and of course you have to make sure that the additional depth will actually fit inside the bell housing. The answer is to go the AP Racing route. They make a clutch which is used in the TVR Tuscans and will handle 475lbs/ft of torque and that more than anyone in the club is likely to have. It is a 9 ½" single plate paddle clutch and will actually fit the existing location dowels with very slight adjustment. You need to fit a new clutch release bearing but the existing carrier can be modified without too much trouble. The clutch is smooth and seems to wear well, I have had one fitted to my car for some time now and have not had any problem with it at all. Several other members have also fitted this clutch and are similarly satisfied. The Clutch is AP Racing and the Pressure Plate is part number CP2394-14, the clutch plate is Part number CP2583-17 and the clutch release bearing is part number CP3457-2. These items are also all available from Tech-Craft Motorsports and a set will cost you around £295.
Last year was the first full year of using my Tornado GT40 on the road and on the track, the car was built in 1995 and has know covered some 16,000 miles many of which have been on circuits around Britain and France such as Castle Combe, Silverstone, Oulton Park, Val de Vienne etc.
This year we are again going to Le Mans in June and hopefully Spa and the Nurburgring later in the year plus various action days and rallies etc in this country.
The cars brakes are adequate for normal road use and will stand up to several laps on race circuits before starting to fade and getting very hot, after all the Granada brakes were originally intended for a fairly light use compared to the hammering they take on a GT40. Some months ago I decided to try and improve things some what by fitting larger disc brakes and calipers, after visiting the racing car show at the NEC and contacting several manufacturers of braking systems including AP Racing, Brembo, Alcon and Wilwood I decided to go for the latter mainly because they were slightly cheaper than the others and also more importantly seemed easier to fit.
About 7 weeks ago I went to Rally & Marine Design in Faversham, Kent who are the sole import agents for the American braking systems. I received a warm welcome upon arrival and was shown their premises which although fairly small are packed with parts of all descriptions for most makes of car, both European, American and far east models.
As far as I am aware Rally & Marine Design is the only manufacturer who produces two kits for GT40 models and has them in stock at all times. Dave who runs the place is an ex Ford development engineer who did his apprenticeship with them, so he knows what he is talking about which is quite reassuring.
The kit parts I picked up are stock items, the front kit is BK32 which contains the 32mm thick x 320mm diameter curved vein discs, Superlight IIA 4 pot calipers, mounting brackets, Ferodo 3466 hard pads and all the nuts and bolts to assemble the items on the car. The fitting is extremely easy and could easily be completed in 3 hours as there is no machining or manufacturing of brackets required.
One point I should make is that if you have 15" wheels then you will have to remove the stick on weights from the inner rim if you have this type and get the wheels re-balanced using knock on weights as the wheel to caliper clearance is only some 4mm.
The rear kit is a little more difficult to fit as the rear uprights will need modifying, this involves removing the packing piece which is welded to the upright in order to line the Granada caliper up with the disc, this is not required with the new brakes. It took me some 30 minutes per side to make the modification. The top hat will also require machining as the inner small lip on the casting will need removing to fit the Ford hubs.
The hand brake was the last item requiring attention as the cables were left hanging with nowhere to go, I therefore purchased from Rally & Marine Design two spot mechanical callipers (LH & RH) which could be used without modification to take the Granada hand brake cables. The main difficulty was to mount the calliper as there seemed no easy way to fit them and use the original cables. The answer was to get Ken Saunders to make me two steel brackets to suit the callipers and also fit onto the raking uprights, after two attempts at making cardboard templates I arrived at a suitable design and gave it to Ken who set about making the brackets which were a little complicated due to the location they had to be bolted to. The brackets I hasten to add fitted without any modification at all, after removing the hub assembly and drive shaft to give access to the upright, I drilled the upright to take the brackets and bolted them to the upright using M6 bolts and Nylock nuts. I then refitting the discs, hubs, callipers and drive shafts.
Once the brakes were bled I decided to try the car out on the road and bed the brakes in, all seemed well except for the pads rattling!! And a lot of pedal travel. I pulled into my drive and applied the hand brake which worked fine and opened the garage doors, jumped back into the car released the hand brake, selected 1st but nothing happened the car refused to move. After opening the rear body section up I realised that the hand brake levers would require coil springs to assist in the release of the hand brake callipers.
I duly purchased a set of springs from Halfords at a cost of £4.49 and fitted them, all now seems well. The chattering pads however had me puzzled and after some 4 - 5 hours of tinkering I still had the same problem even after bleeding the brakes again and making various adjustments. I then decided to contact Dave at Rally & Marine Design to ask if he had come across this problem before, he was very helpful and said had I checked the brake line residue pressure which when the brake pedal is released should be no less than 21bs, upon checking I found I had no residual pressure at all and this was allowing the brake calliper pistons to retract to far thus allowing the pads to move.
The answer lay in two small valves which have to be installed in the brake line as near as possible to the master cylinder, they have the affect of releasing the hydraulic pressure back to the master cylinder when the brake pedal is released except for the last 21bs which has the effect of keeping the pad virtually in contact with the disc at all times and prevent the pad from moving and rattling.
Apparently all GT40s should have these valves fitted because the master cylinder is virtually at the same height as the callipers which allows the fluid to drain back, in most production road cars the cylinder is mounted at as high a location as room dictates.
You may be thinking of fitting an improved braking system so I've listed below the likely cost of the
modifications which are trade prices but are available to club members if you ask.
Rear brake kit BK32A £474.90
Front brake kit BK32 £778.39
Handbrake calliper kit £76.92
Residue valves (2lbs) £36.00
Brake pads £69.60
Hand brake brackets ?
Hand brake springs £4.49
Total £1,440.30 plus VAT
Above is the rear calliper mounting bracket 1 required which may vary from car to car, however specials can be manufactured if required by Rally & Marine Design and this is included in the above prices.
If you want more details ring Dave at Rally & Marine Design on 01795-531871 or contact Mike OsborneBack to the contents listing
I have been asked about rod gear shift linkages so many time that I thought it was about time to write some more on the subject. As I have recently altered my rod linkage system to suit a new gearbox I will use the photographs that I have taken of that system to illustrate the parts. The front end of the system consists of a stick which is made from 25mm x 6mm bar which has an 8mm slot about 40mm long up from the bottom. About 75mm up from the bottom is a 6mm central hole and the top has been tapered and an M8 thread is welded on to take the gear stick knob which was turned from a scrap piece of Aluminium but could be any of your choice. The slotted bottom end of the stick is located on an 8mm diameter peg that is welded onto a 3mm thick plate which in turn is fixed to the chassis side members. Mine is welded but equally as well be bolted on so as to make it adjustable for stick position. The linkage rod is made from « " diameter bright steel bar and the stick end of this first section is fitted with a clevis end which is welded onto the rod. This clevis is fixed to the stick through the 6mm diameter hole already mentioned. The linkage rod is mounted through two « " diameter rose joints to the chassis, making sure that the rod slides smoothly through the rose joints. The other end of this first section is fitted with a universal joint, I obtained one off a second-hand steering column. As you can see the universal joint is positioned just drivers side of the bulkhead, this position has to be set fairly accurately as if it is placed too far forward it will intrude into the drivers seating area. If it is mounted to far back the line of the operating rod will cause problems at the second universal joint in the back. This is on my car which has the KVA "C" type chassis which has narrower sill than the Tornado and the GTD. On these cars the linkage would have to be on the other side of the chassis members or alternatively the linkage rod could be shaped to take it through the area that the standard system occupies At the rear end a special support bracket is mounted onto the gearbox using some of the many fixings to secure it. The bracket supports the twin rose joints which are used to carry another section of « " diameter bright steel gear shift linkage bar parallel with the side of the gearbox and at right angles to the gearbox gear selector shaft. This rod is again a free slide fit through the « " diameter rose joints and the rearward end of the rod has a " L " angle about 3" long welded at right angles to the bar. The angle is drilled through in the same line as the rod and a 8mm diameter rose joint is mounted through the hole. The photographs do not show the gearbox gear selector shaft clamp and 8mm diameter x 3" long drop bar at right angles to the selector shaft, this passes through the " diameter rose joint centre and is a free sliding fit. The other end if the section of linkage rod is fitted with the second universal joint which is the same type as the front unit. The position of the centre of this universal joint is about 1" - 1« " behind the gearbox / engine adaptor plate. Both the universal joints are fitted to the linkage rod by 4mm diameter spring roll pins to allow for easy assembly and disassembly (if required). The operation of the linkage is as follows:- when the gear stick is moved left or right across the gate it rotates the linkage rod, the bottom end of the gear stick sliding along the 8mm peg fixed to the chassis. As the rod linkage rotates the angle drop arm with its rose joint and " link rod up to the gearbox selector shaft pushes the gearbox selector shaft to the right or left across its gate. When the gear stick is pushed forward or backwards the bottom end of the stick pivots about the " diameter chassis mounted peg and pulls or pushes the « " diameter linkage rod which is attached to the stick via its clevis pin single axis pivot. As the linkage rod is moved forward or rearwards the gearbox selector shaft is rotated through the drop bar and rose joint link to the rod linkage, this selects the gear. With the arrangement as described and illustrated the gear gate at the stick is as shown on the left, this I find ideal as you don't crunch your knuckles on the front panelling when you shift into fifth gear. If you don't like this arrangement you can achieve most arrangements by having the drop angle from the rod linkage at the rear reversed to that it points skyward, then again you can also reverse the drop bar from the gear selector shaft so that points skywards and this gives another configuration and again you can reverse the peg and clevis positions on the gear stick to give yet another configuration. If you can't get a configuration that you like then I suggest hat you get and automatic box !!!. The setup that I have detailed here is very suitable for use on the Renault boxes which have the gear selector shaft further back on the box, on the Audi box I found that this rather cramped the area around the universal joint and it was very marginal, I therefore modified this arrangement slightly to give me more room. I fitted two separate rose joint mounting brackets onto the gearbox, one about where the front one of the two rose joints is shown on the twin bracket in the photographs and the second on a separate bracket about 3" behind the gear selector shaft. The « " diameter linkage rod was then extended to take it through the second rose joint in its new more rearward position. The rod was raised so that it passes over the top of the gearbox selector shaft with about 3mm clearance, this is important to avoid clashes of the gearbox selector shaft with the linkage drop arm. The drop angle was retained but instead of forming an inverted L shaped linkage was now a T shape, this drop angle has to be mounted far enough forward on the linkage rod so that is does not clash with the gearbox selector shaft when the linkage rod is pushed rearwards to select a gear. The rest of the linkage was the same as described. It is essential to make all brackets and mountings as firm as possible and that all rose joints are a good but free sliding fit onto the « " diameter linkage rod as any unwanted movements will make the gear shift feel wooly. This rod linkage was based on the linkage used on the original cars but I believe has been much simplified without losing any of the rigidity and accuracy of the original. The original made use of linear bearings and ball end swivels and had cast mounts all of which are very nice but expensive. The system I have described here works fine and will suffice until I get around to sorting out a sequential system. I have not yet fitted an escutcheon plate on the gear stick but intend to make one similar to that used on the original with a flip up section to prevent inadvertent selection of reverse gear. The spring return within the gearbox to the third / four gate position is quite strong and naturally moves the stick from fifth back into four if gentle forward pressure is applied to the stick, it is therefore a bit of belt and braces but will finish off the appearance. The spring return in the gearbox also make the change from second to third easy as that similarly only requires gentle rearward pressure on the stick to achieve, the spring moving the stick and linkage across the gate for you. I hope this proves of interest to those of you considering fitting or changing too a rod linkage, I can assure you that a well engineered linkage works far better than any cable system and some commercial systems !!.Back to the contents listing
As many will know the KVA has the reputation of being the most difficult of the GT40 replicas to build. I think the
main reasons for this is the decided lack of information on assembly of the kit and the fact that only the body shell
and chassis and a few other minor parts were available from the manufacturer. The KVA was the first on the scene
in the UK and quite a few "kits" were sold. As little help was available to builders in the early days many of the
"kits" are still turning up today being completed by perhaps their second, third or even fourth owner. Really the
KVA is no more difficult to put together than any other kit, the only difference is that you have to source the various
bits yourself rather than obtaining them from the one source, the kit manufacturer. Whilst this may be very
convenient it is obviously not going to be the cheapest way of purchasing the majority of parts that you will need.
This is intended to be the first of a series of articles which will be published here in Fortyfication which will take you
through the various stages in building a GT40 replica based on the KVA body shell and chassis kit. The various
assembly notes are to be based on the KVA but will in essence will be very similar, if not the same, for any other
GT40 replica kit build.
As with any project the first thing that you should do is put your tools away, pick up a pen and paper and plan what you are going to do. This will save you many hours of abortive work and much wasted money in obtaining the wrong parts. Because the KVA is just a chassis and bodyshell you are virtually compelled to do this anyway. As with any project of this sort it is always a good idea to seek the advice of those who have already built a GT40 replica and of course that is were the club can play its part. You must decide what kind of GT40 you are going to build, is it going to be as near the original in looks etc. as possible ? Or is it going to be as fast and manoeuvrable as possible and will it be used on the road only or on the track only or perhaps more commonly a bit of both. Are you going to make a show car or just one that is very tidy ?. You must ask yourself all these questions and many more so that you can decide such things as what state of tune will the engine have. This will determine several other parts like clutch and gearbox and will also have an affect on wheels, drive shafts and many other parts. If you go through this exercise and can come up with an outline of the specification of usage and finish that you think you want then you are well on the way towards a successful build. Many people still change their minds more than once during the building phase but I'm convinced that most of these changes are either made because little if any planning was done first off or that they enjoy the building part so much they don't want to finish the job and move onto driving the car, which will bring up a whole new set of problems for you to tackle.
If you have a KVA one of the first things to do is to identify which chassis you have. Here I shall be describing the construction based on a "C" type chassis as that was the best of the chassis suppied and most of the earlier chassis arrangements are usually altered by their owners to improve performance and be similar to the "C" type. How do you recognise the "C" type chassis ? this is a question that I am always being asked. The easiest way is to look at the rear suspension. Fig 1 shows a typical "C" type rear suspension. The engine mounts and rear framework to support the transaxle and rear fibreglass varied considerably but the basic suspension is the same on all "C" type chassis. The front suspension is a double "A" frame and uses a Ford Granada upright. The suspension units themselves are standard 2.25" ID coil springs over dampers and any manufacture of the correct length and spring strength is suitable. More on dampers and spring ratings in a later article. Fig 2 shows the front suspension assembly on the "C" type.
Having identified the chassis you might have to check a few things out and perhaps make some modifications and/or additions to the chassis. The chassis that I have had engine mounts that when the engine was fitted brought the tops of the Weber carbs above the line of the bodyshell, this can be seen in the picture shown in Fig 3. I lowered the engine mounts which were welded to the chassis but kept them essentially the same as shown, in hindsight I should have made a new set of mountings that bolted to the chassis so that they could be removed for easier access when fitting the engine/gearbox assembly. Another thing that I had to do was add some mountings to carry the steering rack. The steering rack that I used was from the Ford Cortina and all that is necessary to get it to fit is to cut about « inch off each threaded end to reduce the overall length by 1" , you can use the steering rack from the Ford Escort but that needs extension pieces made and fitted as it is too short as standard. Many other racks could be used and the only criteria is that they are the correct length, can be made to fit the track rod ends which have to be suitable to fit the Ford Granada uprights. You have to position the steering rack so that the steering column can be easily coupled and to avoid bump steer. Some might not know what "bump steer" is, well its when the wheels are steered by the suspension as it moves up and down, this is obviously an undesirable feature. The reason for bump steer is basic geometry and I won't go into that as I'm sure you won't want to start remembering all that from your school days. As neither the Cortina or Escort racks are exactly correct for the geometry (and I don't know of any rack that is exactly right) you have to position the rack so that you don't get any significant movement of the steering over the range of suspension movement that it will be working over. This should only be around 3" of vertical movement and not the total movement that the pivots will allow. Offer the steering rack up and fit the track rod end to the uprights and then move the suspension through the movement range that is required and check for bump steer movement, when you have this correct note the steering rack position and plan the mountings to suit. The mounting that I added for my steering rack were supported off the lower chassis members but again in hindsight I should have mounted them from the upper chassis members as that would have given me more space for the pedal assembly to be fitted later. I also had to add mountings for the steering column and I changed the cross member below the rear bulkhead window from inch square tubing to 1« inch square tubing so as to provide a good solid fixing for the seat belts and make paneling easier. Other mounting brackets were added to support the rod gear linkage , tanks and air conditioning unit. I guess the comments that I have made about the arrangements that I should have made on the engine mounts and steering rack mountings are both things that could have been avoided with a little better planning so you can see how important it is to spend plenty of time planning prior to starting your build. Other manufacturers chassis have most of the brackets already fitted, however the engine mounts on some are still rather high but I will write further on that subject in a later article. You should still check all mountings very carefully as they are easily added at this stage but very difficult later. Now the chassis is ready for painting but more on that next time.
With many thanks to those who have assisted me I have compiled the following information for a retro fit modification I have fitted to my KVA 'C' type chassis to correct the toe angle problems on the rear suspension.
Those of you who have a KVA 'C 'Type chassis and are unhappy with the excessive toe angles produced by the movement of the rear suspension may be interested in how I overcame my problems.
Detailed below is my interpretation of the problem and a brief record of how I set about curing it on my own vehicle.
Please remember the information provided in this article is given in good faith but no responsibility can be accepted by the author for any damage or accidents arising from its use or application.
Anyone employing the ideas or designs herein do so entirely at their own risk. Please remember no two KVA's are the same, measurements will alter and tolerances will change between every chassis. All dimensions as given are approximate. I hope you will find it useful.