Hot starting issues/boiling fuel

[Peter.Kent]

It’s one thing at modest speed. The draft takes the heat away. Stationary, the Chrysler V8 has 2 caspt iron exhaust manifolds weighing c 50meach. The cast iron takes ages to cool. Then the cast inlet manifoldq and the rest of the engine. It’s no wonder the heat builds up and explains why we see many Bristol’s on a hot day parked with the bonnet popped up. Add that huge Rotomaster to the mix and it’s no mystery that all that insulation has been added. I found that steel tubular manifolds were a good place to start.

[PEU186F]

I second Peter Kents comment re tubular manifolds. My 410 now has free flow, four into one, each side, a fine piece of knitting, and the under bonnet temperature is markedly reduced. The standard cast iron manifolds concentrate heat right up underneath the heads, about as far out of any airflow as it is possible to get.

I have started to get interested in air intake temperatures to the carb and there are now temperature indicator strips dotted about the inside of the air filter casing and we shall see what we shall see when I get a chance to drive it again.

I suspect a supply of cool air to the filter intake might prove advantageous but how to achieve this is not obvious.

Martin Barnes put me on to something that is well worth knowing re hot running and starting issues and handed me the solution free of charge. This was a new pair of float valves. He told me that the float valves wear over time, resulting in over full float chambers and too rich a mixture particularly at idle. After I'd fitted them I realised that the slow running jets had been screwed further and further in over time in an attempt to compensate for the overfull chambers until they were effectively up to the stops.

The slow running jets are now well out and can be adjusted effectively and sensitively.

The car now starts on the button when cold, after a very few turns of the starter when hot AND now behaves impeccably in hot slow moving traffic, whereas previously there was always a risk that it would stall as one moved off.

Hope this may help somebody

Roger