TireSmoke.org

I think there's a problem with gas boiling in the fuel system of the 1978 Lincoln Continental. I'll post more on the issues and answers in the 1978 Lincoln Continental project thread but want to save some of the info found on the subject here.

There's not a simple answer to the question of gasoline boiling point, since gasoline is a complex mix of many liquids with different boiling points, but a range of 100*F-400*F for 10% gasohol is often seen. Had no idea boiling would start that low. A bunch of temperature readings of under-hood things will be done. Think I'll also look for a source of gas without alcohol.

This link is interesting. http://www.hotrodders.com/forum/boiling ... 59034.html

Fuel injection systems with pumps in the tank and recirculating fuel don't have near the problems that plague carbureted engines with block-mounted fuel pumps. Headers no doubt contribute to the problems by raising under-hood temps.

Back in the day when we ran Quadrajet carburetors on heavy
cast iron Oldsmobile motors, we had all kinds of vapor lock issues.
Typically, we could solve the issue by putting (pretty ugly) foam
pipe wrap around the fuel line, which was run out and away from
the engine block which was the stock approach. Usually that would
cure the issue. Sometimes, when it was hot outside and the car sat
for a few minutes after being driven for a while, you'd get some
vapor lock, but it would go away after you got the car running and
some cooler fuel came in from the tank. Fred32V used to run a heat
shield under his carb to keep the heat away from the QJet. The issue
with the QJet is that the fuel bowl is tiny and in the middle of the carb,
sitting on a hot intake. The stuff that we did cured the problem. I'm not
sure what the Ford offers for options, but I'm sure you're not alone
in the boat of Ford guys with the issue. We never had vapor lock issues
when we ran a Holley on the cars because they had such huge fuel
bowls, but when we ran the QJets, we were forced to be creative, and
we were successful. This is just another engineering task for you to
achieve. Good luck!

GM

Lots of vapor lock issues with the '60s 430 CI Lincolns. Ford put recirculating 3-hose fuel pumps on them to cure the problems. Some aftermarket replacement pumps didn't accommodate the return line and there were lots of problems with those as a result. There are businesses that rebuild the recirculating pumps and I've seen no vapor lock reports using them.

Others put an electric fuel pump back by the tank and that appears to be a cure too. Some leave the mechanical pump in place and run them in series. Seems like that would work fine if a high volume/low pressure electric pump were used.