While there is uncertainty about running unleaded petrol in modern cars, there is none at all when it comes to the classic era — the cars must use leaded fuel. Or must they?
Robert Shaerf, proprietor of LV Engineering of West Hampstead, which specialises in preparing and servicing MGs, also campaigns his MGB V8 in the Wilky MG Car Club championship. Though very much on a steep learning curve last year, he did well enough to win the MG Owners Club Hanks Trophy for the best novice. A lover of V8s for their grunt, he bought a well-raced model at the end of 1987, added decals to promote his business, and went racing. The suspension was badly out of sorts, but that was less important than his lack of track knowledge. “When I started racing, I knew the car was basically there. The suspension wasn’t bad but it hadn’t been set up very accurately. It wasn’t properly cambered and castered, but it didn’t matter so much as I was more concerned about learning the circuits.”
He quickly discovered that brakes were the big bugbear. “The problem with V8s is that they are standard. While the MGBs in the championship can use V8 discs and calipers, all we can do on the V8 is take the backplate off the front brakes and put on air ducting and any compound of competition pad. New Mintex brake pads are put on for the race and then used in practice at the next meeting, but they do tend to overheat due to the weight of the car. The rears have all got competition linings and I use Mini rear wheel cylinders because the rear brakes on the V8s are too powerful and can cause the car to snap round.”
Shaerf also found that it was better to skip overdrive third as it was the weak link on the ‘box, and that Yokohama tyres were the most suitable rubber. He was not a frontrunner, scraping around for class places well down the order, so it was a clever piece of promotion and opportunism which brought him into the public eye. His decision to run the V8 on unleaded fuel, however, was not a predetermined bid to attract publicity but a matter of chance.
Terry Burton, an old acquaintance, joined British Benzol as the retail manager and offered the budding racer a deal to run the V8 on a proprietary brand of oil. Always alert to sponsorship opportunities, Shaerf responded by suggesting that, to keep up with contemporary marketing priorities, he should promote British Benzol’s unleaded fuel on his car.
The response was positive, but added a further challenge: if the car was to advertise unleaded fuel, so the argument went, then it should also run on unleaded. Perhaps seeing his sponsorship prospects wavering slightly, Robert agreed wholeheartedly. Thoughts of running a special engine were soon shelved on the grounds of cost, and a conversion was investigated instead. The cylinder heads had already been off at the beginning of the year for a routine inspection, but naturally had to come off again for their suitability to run on unleaded to be checked.
Although Robert is an MG specialist he decided to send them to tuning specialist Peter Burgess in Derbyshire, but conflicting advice confused matters. Austin Rover stated that in no way could the V8 run on unleaded, but contacts at the Leyland Daf truck division insisted that the valve-seats were sufficiently hardened to accept it. The heads were replaced without modification and the car set up on Burgess’ rolling road. As a marker the V8 was first run on leaded, recording 160 bhp at the wheels. The tank and system were then drained and the timing altered, and then it was back to the rolling road for a lead-free test. Much to everyone’s surprise, the expected power loss of 5-15 bhp never materialised, the engine still registering 160 bhp. On the road Robert found that the car felt much crisper and had plenty of power. He did not expect to be suddenly propelled to the front of the grid, but he had his own personal marker in the championship against which to gauge himself. He was more than satisfied, then, when in the following race he managed for the first time to set a faster best lap than his closest rival.
A brief opportunity to run his car on a practice day at Snetterton confirmed just what a pleasant car it is to drive. I was expecting a nose heavy, slow braking, heavy machine, but instead found a car that possessed quite positive handling characteristics.
As Robert suggested, the brakes were obviously the weak link. Although I did not do enough laps to wear them out, I felt that in a close 10 lap race, there would not be much retardent left. The engine had plenty of torque and could make for lazy driving, enticing one to leave it in a gear higher than should be to pull it through long corners, fine for road driving, but less so for track racing. Although unacquainted with the MG’s V8 power, there appeared to be no discernible loss of power through running on unleaded.
It is still too early to make sound judgements on the success of the operation, but the only likely problem is that the valve-seats will not prove hard enough and the valves will sink.
By the time the engine is stripped at the end of the season, it will have done approximately 1000 miles, because Robert also drives his car to the circuit. All the information will then be passed to the research and development department of British Benzol and be made available to anyone who requests it, subject to the petrol company’s permission. Once the season has closed and Shaerf has had time to strip his engine and examine the consequences of running on unleaded, we will report on his findings. WPK