Heat soak vs fuel pressure

[Ranger16]

OK, that makes sense. Maybe just for the hell of it, next time I take it out I'll put an IR temp gun on the float bowls and see what kind of temp reading I get.

 

[ckessel]

Airflow across the engine makes a huge difference. Also where you live as far as altitude, weather, local fuel mixes make an impact on the boiling issue.

 

[Ranger16]

Maybe just for the hell of it, next time I take it out I'll put an IR temp gun on the float bowls and see what kind of temp reading I get.

Last night - :45 min. drive, ambient temp was 80° - 85°, coolant temp was 180°. Float bowl temp was 148°.

 

[383man]

Airflow across the engine makes a huge difference. Also where you live as far as altitude, weather, local fuel mixes make an impact on the boiling issue.

Yes that all can attribute to fuel boiling and vapor lock. I had some issue's a few years ago with the fuel boiling in my carb bowls and the fuel would boil and push its way out of the internal bowl vents and flood the eng. Also when you shut your car down after its good and warm on real hot days the fuel vapors while sitting can push out the bowl vents and into the eng making the eng flooded when you go to start it after a 10 minute hot soak. And if the fuel boils in the fuel lines it can block off the fuel from getting to the carb causing vapor lock and then you don't get any fuel to the carb. On my car a phenolic spacer made a huge difference to help fuel boiling when the fuel in the carb bowl gets to hot. You cant use a metal spacer as that will still let the heat right into the carb as you need to use a phenolic or wooden spacer. And if you run a heat crossover in the intake you can block it off to help. I also routed my fuel line out from under my hood as much as I could which helped a lot for fuel boiling. And I also went to a 9" air filter because the larger 14" air filter held much more heat over my carb fuel bowls so the smaller filter also helped and that took care of my fuel boiling. This cheap pump gas of today will boil around 190 degrees with all the ethanal in it. I also noticed if I was stuck in traffic and turned on my electric fan it would blow more heat over the carb and want to start the fuel to boil. If you have vapor lock trouble running an electric fuel pump can help because the fuel will boil at a higher temp when under pressure being pushed up to the carb. With a mech pump the fuel is being pulled up to the carb by vacuum and it will boil at a lower temp in the fuel line. I just hope they don't make the pump fuel any worse because I don't want to run fuel inj on my 63 as I prefer a carb on it. Ron