Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing heat shield for a crossflow?

Simon

Still the original carburettor? I'm told the current pseudo green activity of putting ethanol in the petrol makes the fuel vaporisation problem worse.

However, if that is the problem, you need to reduce the underbonnet temperatures. I'd suggest trying wrapping the exhaust manifold first as if done carefully, it looks nice and does marginally improve performance as well.

A year or so ago several people looked into the ethanol in petrol issue. Supermarket fuel is the worst for this as they could legally put up to 5% Ethanol in then, it may be 10% now, but not sure if new legalisation has come in. BP high octane has very low ethanol content, with about 4+% being additives to improve burn and clean, I was told by BP less than 1% Ethanol. At the time Texaco and Gulf high octane had no Ethanol, Esso high octane is similar to BP with very low Ethanol. I use any of the 4 mentioned brands high octane in the Roadster and our Cooper S. My investigation came about as the high pressure pump on the Cooper S failed and the BMW Mini dealer said it was due to Ethanol in non branded fuels that attacked the plastic of the pump. Ethanol is corrosive and can decay jets and injectors, as well as plastic and rubber seals, it is hydroscopic and if it separates from the petrol will absorb water. The recommended shelf life of Petrol with Ethanol in a sealed tank is 90 days, in a vented tank 30 day, which is why the Ethanol is added when the Fuel Tanker is filled just before delivery. If you look on the net there is a load on it in the USA as they were foisted with it before us and has caused all sorts of issues in old and classic cars.

Thanks for all this! I think the last lot of petrol was from the local Jet garage, seems unlikely this is causing my problems but I'll try some Esso next time as there's an Esso garage near my workplace in Exeter. Will be looking into the heat shield and manifold wrapping suggestions as well! Not sure if it's the original carb. but it is a Weber. Car runs beautifully when it's running!

This has reminded me. I had the same problem last year when returning from Le Mans on a hot afternoon/evening. Let the car cool down and it was OK. It was thought the problem was with the starter solenoid getting hot as it is beside the exhaust in the CVH, but, of course, it could have been caused by French hypermarket petrol.