Gas

[wlewis]

What gas would be best for my Cobra's 351W crate motor and 65 Mustang 289 HiPo? E10 93 octane or 89 octane Ethanol free (marine gas)?

[Aggressor]

Aggressor is running fine for almost 10 years with 92-93 octane 10% Ethanol pump gas. Her 403 CI FE engine just turned over 21,250 miles. The last 9000+ miles have been with the Paxton blowers providing boost. The only problem to mention is the holley gaskets had to be changed in the 600's to more ethanol-friendly type.
It's an easy call - set your crate engine up to run on readily available fuel. I've driven many times to car shows hundreds of miles away and it's kinda nice not worrying about expensive specialty fuels at limited facilities.
I use the same fuel in my wife's 68 Mustang - 289 4-barrel engine.

-Geary

[Wareagle]

With regard to gasoline with 10% Ethanol, do you guys seem to have more problems with what appears to be vapor lock. I'm running an edelbrock with holly electric fuel pmp. and alot of idling or low speed in hot weather makes for issues. Of course the best answer is to keep the gas peddle depressed and the gears a changin but sometimes there are redlinghts.

rick

[Aggressor]

I had severe vapor lock problems with the first Unique I built in 1991. The smallblock would lockup as if on queue at the most inconvienient times. I was running solid fuel lines from the mechanical pump to the carbs. The solution then was to cut several inches out of the line near the carbs and replace it with rubber tubing. I switched over to Russel steel braided lines in 1992 with no problems since.

- Geary

[Slither]

What caused the performance change Geary? Was it a heat transfer issue?

[Aggressor]

Paul - I really don't have a hard lock on the reason why. The rubber tubing bit may have allowed expansion. Perhaps enough to release heat - If you compress air it takes on heat - expansion releases it -as in an air conditioner???? My engine bay has a lot of russell lines - many in direct contact with the FE. She's running hotter with the superchargers but handling it well.

If you look at the carb feed lines they both drop in front of the engine to hookup at a "T" fitting lying against the front of the engine, north of the waterpump, and under the distributor. From there they cross to the drivers side against a very hot engine. The heat at the idle set screws is so hot that the screwdriver in you hand will quickly become very uncomfortably hot limiting your tuning sessions.

I all I know is that its worked so far.

-Geary