Fuel for the summer

**outasite** · 04-10-2016, 11:46 AM

As we SLOWLY warm up, I'm starting to think about fuel for the summer.In the past @150 psi, been using 50/50 90 rec no ethanol and 100LL @32-1. at that mix I think the octane is a little higher than needed, but has worked well. 90 rec, is getting harder to find,but 92 and some 93 with ethanol is all over.If the ethanol fuel gets all used in a day or so,and not allowed to sit in the tank,is it still poison? This would still be a 50/50 mix so the 10% ethanol would be a fairly small amount per gal.thoughts?

**FMP** · 04-10-2016, 12:00 PM

Been using 91 no alc Shell for years at 165psi and 35* no problem even running to lean side, good oil but no more than 50:1. 94 with alc runs smooth and if you don't let it sit around in the carbs and pumps etc it's fine but be warned it will eat as it's moving through. 100LL even smoother but need to jet it a bit leaner and might be octane I'm not needing so I don't use it often since a rejet and ign takes 20min. Just remembered... "ACES" additive.

**OMCFREAK** · 04-10-2016, 12:52 PM

I add some things to my fuel depending on what type of fuel exactly I'm running. If I'm using an ethanol fuel I put about an ounce of diesel in per gallon. For me this has pretty much eliminated any negative effects of ethanol. I usually also run about a half ounce of Naptha per gallon, as this will eliminate deposits and carbon in the engine. If I'm going to not use the fuel right away I just mix in a couple ounces of IPA with these other ingredients. I've never had any trouble storing my fuel for months this way, ethanol or not. My dad was an industrial chemist and taught me all this stuff.

**eli** · 04-10-2016, 01:00 PM

diesel is like sea foam ,great cleaner. naptha is a drier removes water thats all i know

**Slimm** · 04-10-2016, 01:52 PM

I have been running my 1999 carb 2.5 200 with +180# compression using Shell 93 and ACES mixed with Penzoil Synth Blend @40:1 with no problems. I have a 19 gallon tank and drained about 7/8 tank after sitting for about 3 months and had no water and no sediment on the bottom when I inspected with my tiny little USB camera. Made some unexpected changes over the winter due to an out of round hole and bad sleeve. Plan on running the same this year after I get it broken in.

EDIT: I run what I guess is standard 25° max. I have ran it as high as 28°, but just because I got distracted while setting timing and when I returned to work on the engine I didn't double check the indicator to make sure I was where I needed to be. Luckily I had no trouble from it.

Slimm

**outasite** · 04-10-2016, 02:34 PM

Three different post and three different blends.All good information! Maybe we should start a "share your blend" thread.Where you could post your compression,timing,and mix that you burn.Its always nice to pickup a little tidbit of useful information.So! Some of you other guys sitting on the sideline SHARE! Just please don't turn it into a bash fest on any one fuel,or oil.

**OMCFREAK** · 04-10-2016, 03:38 PM

I mix 93 ethanol fuel with 110 Sunoco to get a 96 blend. 3 liter looper with 160 pounds and 15.5 degrees.

**FMP** · 04-10-2016, 07:56 PM

Originally Posted by OMCFREAK

I mix 93 ethanol fuel with 110 Sunoco to get a 96 blend. 3 liter looper with 160 pounds and 15.5 degrees.

will it make more with more ign?

**90 5.0** · 04-10-2016, 09:30 PM

That doesn't sound like enough timing for that fuel and compression??

everyday boating I'm at 150psi, 93 ethanol fuel and 24 degree total timing with zero additives.

Running a br9hs plug @ .040