Pulling timing with high intake temps on E85?

[MalcolmV8]

The day where I noticed my rails were luke warm to the touch with e85 was a much hotter day 80-90degrees out, I could put my hand on them and hold it there no problem. I don't have a temp reading from a similar outside temp though. But I cant contribute it to anything other than the ethanol absorbing heat from the rails pulling heat from the engine bay.

Humm that makes no sense. Something else had to be going on. Like you just put a fresh full tank of fuel in (cold from underground tank at station) and it hadn't warmed the fuel yet. Or you have a massive fuel cooler with a powerful fan pulling heat from your fuel. Or your car hadn't been running very long and the fuel in the tank was still cool.

Like I said I've done a lot of testing on this and I know for a fact regardless of E85 or pump gas the rails will heat to scolding hot, 200+ F, and the fuel inside the tank is that temperature. You can check the fuel lines, the fuel filter etc.
It makes sense too. You circulate the fuel around the motor and back to the tank and repeat over and over you've essentially created a powerful hot water heater but with your fuel system. Eventually the entire gas tank is completely heat soaked and the same temp as the engine.
That's the whole reason I switched my return system to a dead head. It dropped my fuel temps by over 100F as you probably saw in that link I posted. That's fuel in the tank, lines, FPR. The fuel going up to the rails in the dead head configuration still get very hot. Not as hot as before but still hit around 160F as I recall. It varies in dead head because slow cruise or idling means the fuel sits in the rails longer getting heated where as more aggressive driving consuming gas at a much more rapid rate won't sit as long in the rails... plus the faster driving has more air flow in the engine bay which probably helps.

The only way I'd get cool rails after the car was heat soaked like you pointed out is if we pulled into a gas station and filled up. The rails, fuel filter, FPR, and lines would all have a much cooler feel till the engine heated all that back up too. Like I said the majority of my fuel heat tests were done on E85.

If you're experiencing cool fuel rails once fully heat soaked and driving around for a bit on 90 degree days I think we'd all like to know your secret

 

[JeremyH]

I was quite surprised to see that they were that cool to the touch myself, I have never noticed them that cool ever. It was a hot summer day at a track rental at MIR and had just made a few quarter mile passes. I popped the hood to let it cool and sit like I normally do and that's when I noticed the rails were warm to the touch an not boiling hot like I'm used to. Normally every thing is pretty steamy in general under there after a few passes. Prior to the track runs I drove 2 hours there. I had around 1/8 to 1/4 tank left. I don't have any vapor lock issues and run a low (40psi) base pressure. Most recommend a higher base pressure than that in warmer climates to prevent heating of the fuel in the rails causing hard to start conditions. Since I first noticed it I now check the rails from time to time and its never been too hot to touch since I started running e85.

I really want to do some temp testing again this summer now with pump and e85! I would like to measure feed line temp, fuel filter body, rail temp, regulator body and return line. And do this test on both fuels on the same day after running the car for the same amount of time with the motor still running.

My setup runs a smaller 320 pump as the always on primary pump, it draws 8-9amps and I have 6 gauge power and ground wires going to the controller and 10gauge power/ground going to each pump. My second 465 pump is on a hobbs switch trigger and only comes on when I'm in boost.