Took the inlet valve / seat assembly out, gave it a good look, blew it out with compressed air, but it looked clean. Reinstalled it and re-set the float level with the car running. Seems to run fine since it's now cooled off. Fuel pressure was reading 7.5. Looks like one point for the winter fuel theory.
I have a mechanical pump and -6AN hard aluminum line that runs straight up from the pump and then curves over under the expansion tank, makes a 90deg right turn by the
oil filler tube and connects into a aluminum fuel log that runs parallel to the top edge of the passenger side valve cover. I noticed that the log was in contact with the front valve cover "tab" so I stuck a double layer piece of gasket material in there. I guess there is little in the way of insulation that is keeping the fuel in the line from getting a lot of heat from the engine and valve cover since it's all just aluminum.
I'm considering switching to braided line ie Earl's, Russel, etc. I assume that the rubber inside the line will provide better insulation than the aluminum and I could probably route it further from the block. I'd also probably have to do this to install a pressure regulator anyway as trying to re-shape the tubing will be a pain. Don't know if this will be enough to stop the boiling - if that's the culprit - but appreciate thoughts and feedback on the idea.
Also, would any kind of octane booster or other fuel additive raise the boiling point of the fuel, or do you just have to dilute it down with enough race gas to effectively lower the butane content that's causing the boiling?
Thanks!
Scott
