I'm a great classic car fan and have more than a passing interest in motor racing during the 50's and 60's. I'm also a Mercedes-Benz fanatic and at one stage I owned (at the same time) 1966 230SL Pagoda, a 1967 600 Grosser, a 1964 300SE Fintail, a 1964 300SE Coupe, a 1967 200 Universal, a 1970 300SEL 6.3, a 1978 450SEL 6.9, a 1982 280SL and a 190E 2.3 Sportline. I had wanted to get involved in historic car racing for a number of years and I wanted to race something that was different from the usual choice of Mini, Anglia or Alfa. The only option for me was to get a W111 Fintail.
In July 2005 I found a Fintail advertised for sale at a local workshop. The car seemed in a nice condition, but needed a bit of mechanical attention. A deal was secured and the car was driven home with some difficulty - it turned out that the timing was incorrect and that the carburetors were dirty and poorly set up. Nevertheless, with the help of my father and brother (this became a family project) the car was sorted out in anticipation of putting it on the track to see what it could do.
We took the Fintail to an open track day at Zwartkops one Sunday soon after, and we decided that we would put the car on the track in absolutely standard trim , eager to see what the car was capable of doing . Up until this point there had been many long discussions about the car and the eventual consensus was that the car would never be a competitive race car. However, we decided that it would at least be something different and that it would be fun.
The first outing confirmed our thinking. The best the Fintail could manage around the track was a lazy 2min and 3seconds and the car felt heavy and underpowered. The handling was okay, but the car rolled a lot around corners and the standard high profile tyres didn't grip that well. It certainly was no race car.
After our outing, we drew up an immediate list of things that needed to be done to get the car race prepared. After these initial modifications had been completed, further assessment could be made of what needed to be done:
1) Remove the front and rear bumpers
2) Remove all interior fittings, but retain the door panels. This included the heating and ventilation system.
3) Get a roll cage made and fire extinguisher fitted, as well as an external electrical cutoff switch to comply with basic motor racing requirements
4) Fit a FIA compliant racing seat and seat belts
5) Have shorter and stiffer springs fitted, as well a new shock absorbers.
6) Buy a set of 14" Baroque style Mercedes rims and fit lower profile road tyres. Road tyres with a DOT rating were required according to the regulations for the Pre '66 Legends Series.
It was decided that getting the handling sorted out was more important than trying to get any more power out of the engine. The car would simply not be able to handle any more power as it was. We set about doing the required modifications and the car slowly started to take on the look of a racing car.
The car made its debut at the registration day for the Historic Racing Register at the end of January 2007 and passed all the mandatory requirements that were necessary to go racing. The Fintail was met with some mixed reactions from fellow competitors, from cynical laughter to outward enthusiasm. Generally the car was well received and we were extremely excited to finally participate.
The Fintail was entered in the much anticipated Golden Age of Racing at Zwartkops on 4th February 2007, which is South Africa's biggest historic racing festival. The festival is an international event with many British and European cars and drivers participating, notably David Piper. The car managed to qualify in a time of 1min 33sec, which put me 14th on the grid. I finished Heat 1 15th and Heat 2 14th, resulting in an overall 15th out of 20 cars and a third in class finish. A bonus was that the next night the Fintail was featured in a short clip about the international event on the evening news.
In the queue for scrutineering on race day
We decided that the car had performed very well and it proved to have very good handling characteristics, although there was still room for improvement. We missed the next two events while further modifications took place. The cylinder head was removed and skimmed to raise the compression ratio as well as polishing the inlet and exhaust ports. The camshaft was mildly re-profiled and a new inlet/ exhaust manifold was made to accommodate three 40mm side draught Weber carburetors. The top control arms were slotted to give the car as much negative camber as possible and a second anti-roll bar was fitted on the front suspension. Harder springs were fitted and a set of special shock absorbers were made for us by Bilstein.
These modifications resulted in a 7 second improvement on my previous best lap time.
Up to this point, the car was steadily improving as a racer, but aesthetically it remained tatty. I imported front and rear screen rubbers from the US and then set about stripping the car to have it re-sprayed. I managed to arrange a sponsored re-spray through L&M Autobody in Pretoria where I would supply the paint and they would do the job for me. Karel, the owner of L&M Autobody is a keen classic car enthusiast and has done some great work on classic cars. While the car was away, I set about fabricating an air box for the air filter, which would be attached to the carburettors. The result was very successful and the car now runs with a new air box using a Jaguar XJ6 air filter.
When I got the car back, I was astounded at the quality of the work, which was of restoration standard. The car was totally transformed and it now looked like the racing car which I had wanted all along.
Before
After
I then stared to re-assemble the car, and during the process the side windows were replaced with 3mm clear polycarbonate sheet, to save weight.
The air box consumes a lot of space, resulting in the oil catchment tank being moved to the boot, with some delicate pipe bending work being done by my brother.
The radiator was re-cored with a modern high density core to cure the overheating problem and a thermoswitch was also fitted to the bottom of the radiator for the electric fan. A used auxillary fan from a W126 series was fitted to the front of the radiator and the old mechanical fan was removed. The fan switches on and off automatically, but also has a manual override switch. My father spent many hours on the front suspension removing the lower control arms and slotting the mounting points with a die-grinder to give the car more negative camber. We found that the car did not have enough negative camber, even after the last modification. Finally, a set of semi-slick tyres was fitted for extra traction.
The first outing of the year took place at registration a week before the second annual Springbok Series Revival meeting on 3 February. The car performed extremely well and I managed a best time of 1min 24 seconds - two seconds faster than ever before. Later on, the car started to misfire and we struggled to find the fault before race day. There was also a problem with the clutch hydraulics and we replaced the clutch master cylinder seals, as well as the seals on the slave cylinder, but the problem would not be solved. Eventually the problem was solved by bleeding the system properly, on the recommendation of my friend, Lou Faul. The lesson in bleeding a clutch on a Fintail:
Attach a pipe to the brake caliper bleeder screw and the other end to the bleeder screw on the clutch slave cylinder. Open both bleeder screws and pump the brakes, thus circulating the fluid and bleeding the system.
By race day the car was still misfiring and we had already replaced the spark plugs, plug leads, distributor cap, rotor, coil and condenser. After first practice, we decided that the only thing we had not changed was the distributor, and we found that one of the centrifugal weights had come off its spring. Lou took over and quickly overhauled the distributor and we were upbeat that we had found the problem, but the car still misfired. We eventually fitted an electric fuel pump in series with the mechanical pump and this seemed a lot better, However, the new electric pump seized during the race and the problem reappeared. The conclusion was that there must be some sort of blockage in the tank, which still had to be verified
The result was that the car was decidedly off form, but the racing was still fun. The car was shared by one of the British drivers, Max Wakefield, who has become a good friend over the past few years. Max is an enormously competant driver and has raced an array of fast cars. He owns and races a Ferrari P4 replica, which is currently being fitted with a Ferrari F1 motor, and has also raced an early 90's Bennetton F1. In 2006, he raced an Austin Healey at the Le Mans Retrospective, so there is no doubt that he's a man of quite some experience. Even though the Mercedes was a bit sick, Max was very impressed with the chassis and handling, and said that in his opinion, the car could have handled another 200 hp. His statement speaks volumes about the fundamental engineering of the Fintails!
The end result was an overall second in class, which pleased me, but the frustration of having an under-performing car was offset by a wonderful atmosphere of enthusiasm, good friends and beautiful cars.
In preparation for the next event, we set about finding the source of the misfire. We weren't sure whether the problem was fuel or electrical and decided that the car needed a smaller plastic fuel tank anyway, as well as a high pressure electrical fuel with a re-circulating system. We bought a smaller plastic fuel tank and fitted into a fabricated aluminium frame on the boot.
The new fuel pump as also fitted in the boot and a return system was made, along with a new fuel pressure gauge, which was mounted in the wood radio cover.
The battery was also moved into the inside of the car and a new control panel was made with an adjacent manual fuel cut-off valve
We took the car to the track to test it, but the misfire persisted. However, this time we could see that there was enough fuel pressure. Eventually we found that one of the channels that runs down to the needle and seat on the front carburetor had a partial blockage, and this explained the problem - the one carb was running out of fuel. The blockage was eliminated and we then sent the car for a dyno test. During the dyno test, the mixture was set to optimum by replacing some of the jets, as well as the timing. The result was that an extra 15Hp was found and the car was now giving 103Hp @ 6000rpm on the back wheels. That translates into roughly 130bhp on the engine at Highveld altitude.
The next round of the 'Legends of the 9 hour' series took place on Saturday 28 July 2007.
Raceday was a cold winter's morning and the wind was particularly chilly, resulting in a low spectator turnout. I went out for official practice at 8:45 and the car performed beautifully, achieving my best time yet of 1min 22.8 seconds. That placed me 10th on a grid of 20 cars - I was thrilled. The first race got underway at 12:10 and I ended up improving my time to 1min 21.8sec and finished 8th overall. The second race was one of the most exciting I have ever experienced. I got away 8th on the grid and by the second lap I was locked in a tight battle with Shaun Cabrita, who drives an Alfa Guilia. The race was extremely close and there were a few times that the car was pushed to its limit and I almost lost it. Eventually Shaun pipped me at the post and I came in 8th again. I set my best time ever of 1min 21.6sec during the second race and ended up winning my class. It's now quite clear that I'll be bumped up to the next class.
A lot of people were surprised at the Mercedes' performance, myself included. Shaun's Alfa is a good 200kg lighter than the Mercedes and the two cars have a very similar power-to-weight ratio - about 83bhp per ton. The Mercedes handles far better than the Alfa - I'm able to brake far later into some corners, and some corners I don't brake at all. However, the Alfa being the lighter car manages to pull out of the corners faster than the Mercedes.
The Mercedes has gone beyond all expectation and proven to be an extremely well balanced and surprisingly competent racing car.
We took a decision to race at the border 100 in East London in December. The existing fuel tank would have been too small - East London is a lot longer than Zwartkops - so we decided to fit a larger 45 liter tank
On our return from East London, we removed and stripped the engine. The valves had been touching the pistons, so we had the head skimmed slightly to ensure that it was straight, and then the pistons were pocketed to create a bit of extra clearance. The crankshaft, conrods and pistons were balanced and the flywheel was lightened by about 2kg. The inlet/ exhaust manifold was also sent away for ceramic coating, which apparently reduces under bonnet heat. We also went on a major campaign to reduce the general weight of the car, and all unnecessary plates, brackets and hinges were removed. We ended up saving about 45kg. The rear windscreen was also replaced with a polycarbonate sheet.
At the Kyalami meeting at the end of August 2008, the car developed an oil leak on the driveshaft oil seal. We decided to remove the diff to renew the seals and bearings, but at the same time we decided to weld the spider gears of the differential to stop the inside wheel spin through quick corners. We also replaced the bushes on the trailing arms with nylon bushes to further firm up the rear suspension. We found that the diff mounting was worn, as well as the yolk bush of the driveshaft. Both these bushes were sent away to be re-conditioned.
