E85 Advice

[Topsp33d]

I’ve posted a few threads about an engine we are machining and building a big stroke 351w based engine that has high compression and I’m leaning more and more towards e85 since we have a station nearby. The long block was on the edge of detonation so I am nearly convinced to run corn but then a video popped up in my YouTube feed that shows an example of problems associated with e85, namely sludge and deposits. Around 10:00 he shows the piston rings basically welded

https://m.youtube.com/watch?v=bPcVBc4-5Mk

I’m wondering what advice you would be willing to give to running that fuel, specifically about issues regarding milking and condensation and carbon deposits etc. also any fuel plumbing precautions I should take.

This particular engine will be run on the street, raced on the quarter, and hopefully make it to a road race event a few times. I was hoping to run carburetor since braswell is in my town and we could dial it in but my machinist and tuner recommend efi, so any issues specific to carb or injection are very welcome as well.

[BLSTIC]

I've heard of oil dilution being a thing with high alcohol content fuels, which would certainly match "milking and condensation". It was also a concern with high water injection levels in ww2 aircraft.

The general solution to keeping it at bay between services was to get the engine and oil up to temp fast, keep it that way, and have long drives in the mix. This evaporates alcohol and water oil from the oil (as well as most parts of gasoline that might also be mixed in there).

One way to do that is with a coolant-oil heat exchanger so that the oil temperature heats up with the coolant instead of the usual several-minutes-later situation. If you're concerned about oil *over* heat road racing with one of those as an only cooler there's nothing stopping you from also running an oil-air cooler on a thermostat controlled circuit.

I imagine that a crankcase vacuum system would also help with boiling out contaminants, as it's certainly been reported that the oil looks cleaner. Constant vacuum can almost be achieved under street driving with a trick PCV setup, or all conditions if you run a pan-evac as well and don't have cat converters or o2 sensors.

Anything that helps mixture preparation is going to be your friend as well, as you'll be having less excess fuel in the mix. If you can, get an annular venturi on the primary side at least.

[KnightEngines]

Vac pump to keep the oil dry, 6-8" of vac is plenty.
A bit of methanol fuel stabiliser additive to keep seals etc lubed.
Seal the fuel tank between drives (put a note on the steering wheel so you don't forget to uncork the breather).

If it's going to sit over winter or whatever then drain the fuel, put some regular fuel in & run it till it splutters. Misting the engine isn't a bad idea either.

There are far more horror stories than thruths out there.
It's not a big deal to run a Streeter on e85, just do the preventative maintenance & everything will be roses.

[tuffxf]

Listen to Tony above,
if its milking the oil your tuneup is out to lunch or set up is completely wrong.
Treat it like methanol and you wont have an issue, treat it like normal fuel and you'll have dramas.
Fogging oils and upper cyl lubes like Klotz uplon are great!

[chimpvalet]

Any suggestions on coolant-oil heat exchanger choice?

[fabr]

I have run e85 for many years.I am a firm believer that 99.9 % of issues are due to running pump e85. Use high quality anhydrous e85 (I buy drums of e98 and blend to 85)and there will be no need to drain the system if left to sit over the winter.Ditto on the efi being best choice and always cap the tank vent after a drive. The note reminding you to uncap it is more important than it would seem. LOL!! BTDT LOL! Milking is just piss poor tune.

Note: the above does not necessarily apply to drag only use.

[Topsp33d]

Is it better to run a higher cooling system temperature?

[BLSTIC]

Is US pump e85 actually e *up to* 85? Changing by season and location?

I don't know how a carb would deal with that variability in fuel.

[Topsp33d]

Yea honestly I think it varies by location and time of year for pump ethanol. I called my local hot rod shops and they can get me torco “t85” with the additives for $60 a pail or $500 a drum. Those are guaranteed 105 octane or whatever but it’s triple what the local pump is offering, hmmm….

[mt-engines]

Is US pump e85 actually e *up to* 85? Changing by season and location?

I don't know how a carb would deal with that variability in fuel.

In a pinch while leaving a popular cruising spot I stopped at a gas station to fill up because it was the only one close enough with e85. 5 gallon fuel cell, 5.38 gears and a 30 mile trip I had to buy whatever... well about 2 minutes into the drive it started misfiring so bad I thought I lost some pistons.

Trailered it back, checked the fuel and it was barley 75%..

From pump to pump.. both measuring 85-88 I've lost .300 to the 660. With some gas stations fuel. Some smells like whiskey and. Some smells a skunk. Maybe they water it down, after all your only measuring the petroleum hydrocarbon conten.

There are a few golden places around me that sell it around 88-90 and its super cheap at around $2/gal.

The stuff I use at the track is leaded e85? Its a lot more expensive, but on a nitrous engine or a boosted engine its cheaper than buying new parts.

[KnightEngines]

All of our local pump e85 comes from a single source & tests at 89-92% consistently, but I know this isn't the norm even in other parts of Australia.
Local street/strip guys have it dead easy, consistent e85 on pump all over the city.

[Rick!]

Is US pump e85 actually e *up to* 85? Changing by season and location?

I don't know how a carb would deal with that variability in fuel.

Here are the specs for E85 in the US. It's blended in the tanker at the fuel depot/terminal. YMMV.

[Topsp33d]

Yea the scariest part of converting to ethanol is the wild range of pump gas. I am aware of racers testing their fuels before race day so they can compensate delivery, it seems archaic almost, but if you are running at the limits it must be necessary.

My tuner suggested we run a flex tune setup where it just computes the correct amount of fuel depending on the grade. That’s actually a comfortable program pending you have all the sensors, which I do not. I have an accel dfi vii rig and the consensus is to just upgrade to have the adjustment but i still kinda want a carb and a distributor haha

[fabr]

The scariest part is all the BS horror stories.99% of which are wild exaggerations or are not actually the fault of ethanol.

[VW16V]

Needs decent oil temp (enough to boil out condensation) when running E85