REQUIEM FOR A GSM DART – CHASSIS #6317
This Dart was manufactured in South Africa in mid-1963. It ended its life in a major accident at Road America on July 15, 2016 when I spun off the road at the exit from the carousel and hit the wall head on at circa 70mph.The car held up pretty well because of the integrity of the main chassis tubes although the whole chassis was ultimately bent, perhaps repairable but at some risk and considerable expense. I did not do so well, emerging with a broken back, more specifically a badly burst L2 vertebra from which I have miraculously, recovered quite well.
I bought #6317 from Pieter Du Toit, a Dart collector in late 2001. He had been a Dart fan and collector in South Africa for some time and had raced them for years in vintage racing groups. I chose it from amongst 4 he had available. Its early history I don’t know.
A frame off restoration was done and it was repainted cobalt blue with a gold stripe but no suspension or shock/brake modifications were done. An engine built by well-known South African Ford Escort racer was fitted. It was a 1640cc Kent crossflow with his own design cams and a nitride cast iron crank. He claimed he could get up to 190 bhp from these motors but this one was way short of that and it gave endless trouble initially as the cam was so severe that the valve springs were binding leading to the cam snapping in half twice, ruining the motor on the second occasion. On another occasion the #4 bore split open at high rpm because it had been bored improperly and that also ruined that motor. But more on motors later.
We had been living in SA while I was CEO of GoldFields from 1998 thru 2002 and brought the car back with us to the US in late 2002 to Denver where I started to campaign it in US vintage racing. Initial results were disappointing. The car was way too soft, the chassis twisting under corner Gs’ to the extent that the front wheel lifted off the ground by 6 to 9 inches and it pushed badly. The original brakes i.e. the 315 Consul discs on the front were poor and as I noted before, the engine weak and unreliable. There were many DNF’s. For objective reference, the best time I ever saw at Road America in this trim was a 1.53. A lot of development lay ahead.
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The first thing we did was to weld in an x bar across the chassis underneath and to bolt in a cross member under the gearbox which stiffened the whole chassis up quite a bit. The result was it became a fairly neutral handling car that could be driven on the throttle in turns and this allowed for some quite impressive drifting in corners although ultimate grip was not high. Times started to improve into the high 1.40s at Road America. At the same time we built a more reliable motor, still 1640cc with a cast iron crank and about 150bhp.
In, or around 2009 I changed race shops to Greg Jacobs at Ignite Performance. Greg is a very gifted mechanic, fabricator and race specialist and after a couple of years of fiddling with the then set up we decided to do a complete rebuild and some redesign. The motor has built by Bill Bradford and on the first dyno run it made 192 bhp at 8000rpm and was still climbing at that point. Unfortunately, his motor too succumbed tThis one was much more extensive. To start with we took the fiberglass body off the chassis and a lot of excess glass was removed to lighten the whole car and a lot of old paint too. The front suspension was redesigned , eliminating the transverse leaf spring front set up and replacing it with separate coil overs and adjustable shocks. The front single control arms were replaced with wishbones and the heavy vertical arms and heavy brake set up were replaced with much lighter units. At the rear the A arm locating the rear axle was replaced with a much longer one and the mounting points on the diff much strengthened. The bottom trailing arms were removed and only the upper ones retained. Stiffer rear springs and better shocks were installed. Further stiffening was also done.
At about the same time I was able to buy, thru a connection at PHP Engineering, a very special Kent motor. It had an AX block bored out to 87.5 mms, a steel crank good for 8500 rpm and a unique cylinder head from a guy who worked at Cosworth which allowed for larger inlet valves by moving the guides further apart in the head. On a flow bench it outflowed the regular Formula Ford head by about 200%. With a Kent 254 degree cam it made good power from 4000 thru 8000rpm.
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Brakes were replaced with Wilwood two pot calipers at the front although we kept the rear drums but with better brake pads. In the process we discovered there had never been enough brake pressure to the rear brakes and that they had been very lazy in the past. With the right rear pads and the right pressures the car really started to brake well. Weight had been reduced in this exercise from 1450 lbs. or so to 1310lbs and I could now out brake the Porsches. I also went and raced a Porsche GT 3 for a year in the professional Le Mans series and really learned how to drive.
And then we set out to go racing.
After all the stiffening work and the lighter front end the car’s handling had changed. It no longer was so neutral. In long sweeps it was especially fast and had very good grip and was very stable but in tighter turns it pushed quite a bit – it was almost impossible to spin it. So, again we had to work on spring, shock and sway bar combinations. We never fully eliminated the problem so I changed my driving style to trail brake the car into tighter turns, (much like the Porsche we drove in the ALMS) it brought the car alive. Allowing me to dive deep into corners on the brakes and with the extra weight on the nose it turned like a demon. Turning inside and passing the big bore cars in the slower corners was a lot of fun. When we had the brake balance right, the right tire pressures and the right atmospheric conditions for the motor to run well the car was unbeatable. The lap times achieved (see below) illustrate it.
There were also initial problems with the motor. The South African made AX block was extra beefy and could be bored out to 87.5mm but at that bore the cylinder walls were down to about 100 thousands of an inch and the bore separation in the cylinder head was down to millimeters. Predictably we had head gasket problems and ultimately a bulging cylinder leading to the motor failing early. A new AX block was found and the motor rebuilt again at 87.5ms.AX blocks were like hen’s teeth and v hard to find. This time a very special exhaust system was installed. Above 7500rpm it added an amazing 14 bhp over a stock Formula Ford headero gremlins this time an inexplicable loss in oil pressure which caused me to withdraw from a few races. We took the motor apart and could not find the problem despite an exhaustive search. It was only after a second tear down did we discover that there was hole in the end plate of the oil gallery which was releasing oil when pressure got over 20lbs or so.
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There were no more AX blocks to be found so we went to Wentz and bought one of the newly cast Formula Ford blocks which are much meatier than the old blocks and bored it to 85 mms, the smallest that the Cosworth head could fit. This worked well until we raced at Mosport in Canada where they were charging $14 a gallon for race gas. A pirate vendor came round the pits offering a special high octane blend he claimed was approved for F1 use and we bought 40 gallons. It certainly worked, as the cars ran well on it despite producing a noticeable black exhaust fume. What we did not know was that it corroded all the brass in the carbs and fuel pumps. We only discovered it at the next event at Road America where the motor would go off song towards the end of the straights. The vanes in the fuel pump had corroded and one had got stuck leading to low fuel flow at high rpm and the motor going excessively lean which in turn lead to small cracks in the special head and a scoured bore from a plug dropping an electrode. Again, with help from some of Greg’s contacts we were able to rescue the head with a special hot ceramic flood poured into the water passages which sealed all the minor cracks and restored life.
It was in early 2016 that we decided to do one last final concours level rebuild, this time frankly with the intent of only doing one or two races and then retiring the car and perhaps selling it on auction or mothballing it. This time we took the body down to original fiberglass. We discovered there were some 13 coats of paint on the car and we guessed some 80 lbs. of old paint came off. A complete frame- cage around the driver was installed and even more stiffening put in along with a better roll bar. This ultimately led to my undoing as it made the car so stiff that again the understeer got pretty bad and because we had done no testing before going to Road America I was not aware of the new handling and consequently went off on my second lap of practice at the exit to the carousel and hit the wall, and so ends the story.
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I won many races outright in the car and also had many class wins over time. In its final form before the last rebuild it was at its fastest despite having a smaller motor and the rev limit turned down to 7250 to preserve life. Horsepower was down to about 180 to 182 and with the larger 205 series tires top speed at Road America into turn 5 was 130mph at about 6400rpm - max power was still at 8000 so the car was under geared. However, it would get from 40 to 90 mph pretty much as quick as the big bore cars and according to my data system quite a bit quicker than my 317 bhp Datsun 240Z. It also, in its later stages, had fabulous grip and reliable trail brake turn in. On tighter tracks this allowed me to run towards the front and a couple of times right at the front against the best of the big bore cars and with some of the 3 liter IMSA GTO Porsches. Its best time at High Plains Raceway was 2.02 mins, by far the fastest ever done by a C Production under 2 liter vintage car. I finished one race where I started mid pack in the big bore group and ran down and finished second, one second behind a Camaro that had won the Vintage National Championship with SVRA. Quite a feat for a little South African1600 cc sports car designed and launched in 1959 built with irrigation tubes for a chassis.
Other memorable races included Road Atlanta winning the Enduro, and several wins in Group 2 at SVRA events at Road America (the organizers eventually banished me to Group 8 with the newer post 1965 cars where I still used to finish well up the order but the car did not have the legs for that long track) Another great class win was at Mosport where I was the only small bore sports car to get under 1.40 with a 1.38 time beating a Chaparral in the process. Other significant wins were in Group 2 at Mid-Ohio and Motor Sports Park in Hastings Nebraska where I set another small bore track record at 1.39 flat. In the 2013 National Championship I was put in Gp 8 with some very big bore Porsches and 914/6s and only finished 8th again hampered by a low top speed on the long track. There were many, many races –over 14 years I did over 50 actual weekends (2 or 3 races per weekend) in that car and loved every one of them. My accident and broken back notwithstanding it was all worth it.
Weight _ 1310lbs dry.
Power – At retirement 180 bhp
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Torque – 155lb/ft
Tires – 205-60-13
Top speed – with 5 speed box and overdrive 130 mph at 6400rpm
(Best seen with 192 bhp motor and 4 speed box and 15mph tail wind at RA front
Straight 8200rpm or 142 mph)
Best times; Road America - 1.40.1
Mid Ohio 1.42.3 where I had poor brakes.
ADIEU MY FRIEND I SALUTE YOU FOR YOUR BIG HEART.
STORY BY: CHRIS THOMPSON