29-09-2018, 09:54 PM
Jon,
I'm interested to know the theory behind removing the hotspot. I always understood it was there to help vapourise the fuel after atomisation. I realise that modern petrol has a lower vapourisation point but doesn't this create problems in the body of the carb rather than in the choke area? Are you trying to reduce heat transfer back to the carb body?
The reason I'm asking is that I have a special with a tubular exhaust manifold and SU carb which runs well in warm weather but badly when it's cold. Living in Inverness this reduces the Austin Seven season down to a couple of months! I suspect part of the problem (just part) is lack of vapourisation.
Peter.
I'm interested to know the theory behind removing the hotspot. I always understood it was there to help vapourise the fuel after atomisation. I realise that modern petrol has a lower vapourisation point but doesn't this create problems in the body of the carb rather than in the choke area? Are you trying to reduce heat transfer back to the carb body?
The reason I'm asking is that I have a special with a tubular exhaust manifold and SU carb which runs well in warm weather but badly when it's cold. Living in Inverness this reduces the Austin Seven season down to a couple of months! I suspect part of the problem (just part) is lack of vapourisation.
Peter.