E10 vs Recreational(no alcohol) fuel

[gofastsandman]

Originally Posted by Bushwacker

Conner sent me a note a couple days ago about a temporary problem he'd had with both his main and kicker engine. Here's the reply I sent him along with the relevant links to the E-TEC Forum, which is an excellent forum BTW, much like CSC, with support from a number of very knowledgeable BRP techs:

Here is some background info on some of the characters in the discussions in attached links to give you a feel for their credibility: LourPitcher is a retired NASA engineer and electronics expert in Texas that runs a 75 mph bass boat and comes from a family in the oil/gas business; Steelhead is a private pilot in Alaska and may be a petroleum engineer. Seahorse is a very savvy BRP tech rep. Evinrude/Joe is the owner of the website, dealer Barnacle Bill in NJ. Huey is a dealer/tech in Australia that's been selling all brands of outboards for 40+ years, and seems to be very knowledgeable. Olypopper is another very experienced dealer/technician in Alaska. jimh is an electrical engineer in Michigan that tends to over-analyze everything, but occasionally comes up with some good info.

1. This thread was started by a guy with a 250 on a bass boat that blew a hole in a piston, evidently due to detonation, either from bad low octane phase separated fuel or lean combustion/restricted fuel flow. The relevant discussion begins with post #40 on P3. Very interesting info about a dealer finding small amounts of ethanol in gas that was supposed to be ethanol free! I have an ethanol tester and I guess I should start checking the Rec 90 gas I've been buying!
2.This thread was started by a guy that somehow got a lot of water in his fuel, asking what to do about it.
3.Another thread with a very good discussion of ethanol related problems; see post #9 for a discussion of problems/myths/truths of E-10 gas by petroleum engineers; see post #21 for comparison of water and ethanol molecules sizes in microns vs. Racor filter capability.
4.Good discussion on mixing E-10 and Rec 90 gas.

I think Pelican is right - the amount of water that gets into a tank via the vent/moisture condensation is miniscule and I think that was proven by some tests/calculations run by jimh. Will have to see if I can find that post. Water in the fuel most likely comes from the dealers tank, or a leaky seal on the filler cap, a vent line without a loop in it to prevent sea water from entering in rough seas, leaks around the sending unit, or corrosion in the tank! During the ~700 mile S. Fl. circumnavigation trip I made in 2010, I used 158.5 gallons and refueled 9 times with Rec 90 gas at marinas. Since I have the Racor with the plastic bowl and drain fitting, I drain a bit of fuel to check for water every day on such a trip before refueling. I found water after 4 of the 9 refuelings; the places is suspect had water in the gas were in Clewiston, St. James City, Gasparilla Marina, Sanibel, and Chokoloskee. Those places are close enough together, that I wonder if maybe they all got watered down Rec 90 fuel from the same distributor?! I've removed my tank a couple of times and it has zero corrosion on it (not foamed in!), the sending unit is well sealed with Permatex No. 2B gasket sealer, I had replaced the filler cap O-ring before the trip and the vent fitting had a special inverted U in it to prevent water entry, so I'm sure water was in the fuel when I bought it. I found NO water in the fuel after Flamingo or any subsequent fuel stop on the east coast of Fl.

The real problem is the margin on the sale of gas.

E 10 caused me to change three filters within 60 hours when I bought my 20.
A strong solvent. Sludge factor 5.
Great clamshell for the vent.

Why is he always smarter than I am?

Did he plan on keeping his boat for 50 years?
He has a 340 mill in that old bathtub glass Cuda...

[NoBones]

Originally Posted by gofastsandman

Why is he always smarter than I am?

Quite simple..

He is a rocket scientist (literally)
You, a carpet bagger...

Me just try to keep up...

[DonV]

Originally Posted by NoBones

Quite simple..

He is a rocket scientist (literally)
You, a carpet bagger...

Me just try to keep up...

Ken, did you mean "slacker carpet bagger"?

Me, I gave up trying to keep up.....

[cdavisdb]

Ok, I got the idea on the fuel vent, will see what I can do. Given where mine are located, it really should not be a problem.

I've now looked at a bunch of ethanol testers, most too small to be very precise. I've got one coming that is larger and has some colorant to make the gas/water line more visible.

From what I've read, the real danger is small quantities of ethanol in the Rec90, like one percent or less, so that a minimal amount of water will produce phase separation. That can happen multiple times and the sludge build up in your tank. I feel the need for a testor that will measure small quantities of alcohol.

I'm still going to check everything. The holes in the top of the fuel tank is a real possibility, I had very close to holes in the top when I took the tanks out 4 years ago.
Hard to see, too. Otherwise, the tanks were perfect. My setup allows my nose to access the area around the fuel tank, never noticed any smell, not sure that is definitive.

[Capt Terry]

Even when I have a comment on an issue, I usually wait because Bushwacker will do a bang up job of explaining it (just like he did when I was a young engineer at the jet engine plant). I was going to skip this one too until it sounded like Connor had too much water. I previously reported some of my issues from several years ago with E-10 with an 1985 Merc 150; I was having a devil of a time. First thing I was getting larger quantities of water than one would expect. My fuel hatch was not caulked (but that may have been part of the problem) which made the hatch to remove for inspection. I seldom had a fuel odor and didn't lose fuel. But, upon removing the foam along the sides of the tank discovered some holes about halfway down on the tank. At the time the boat was stored outside, so apparently some of the water was leakage from wash down or rain. I subsequently replaced the tank. My issue got much better until I was having engine running problems usually after a lunch break (almost like a vapor lock- soft fuel bulbs, etc.) I replaced all the rubber, filter, etc. up to the engine and converted strictly to non-ethanol fuel and my problem was resolved. I continue to use only non-ethanol on my 3 year old ETEC 150 HO and replace the water separating fuel filter at least once a year. So far so good, am approaching the 3 year maintenance.

[Capt Terry]

[QUOTE=Capt Terry;244318] which made the hatch to remove for inspection. QUOTE]

This was suppose to be this made the hatch easy to remove. Trying to watch the 2 & 4 year old grandchildren while typing didn't work too well. Any other errors, you'll catch the drift!

[DonV]

My issue on water entering the gas tank, which might help someone else.

On my 18' Kenner the "pie hole" cover was not sealed at the deck when manufactured (very sloopy production) even though it's a waterproof cover with an o-ring seal. Water was leaking down directly on the fuel gauge sending unit. After many tries resolving the excess water in gas issue, draining the tank twice and three or four Racors later, I figured out the water was leaking into the tank at the rubber gasket at the sending unit. Real simple, just put water on the high side of the gasket with an eye dropper and it disappeared under the gasket. Every time it rained or you washed the boat water was entering the tank. Some 5200 around the mounting base of the pie hole plus generous amounts of Permatex #2 on the sending unit gasket and no problems since!

[76Red18]

Fill that tank up after every outing to get that humid air out.

[Bushwacker]

Originally Posted by cdavisdb

. . . From what I've read, the real danger is small quantities of ethanol in the Rec90, like one percent or less, so that a minimal amount of water will produce phase separation. That can happen multiple times and the sludge build up in your tank. I feel the need for a testor that will measure small quantities of alcohol. , , ,

If you approach the Rec 90 vs. E10 decision from a "consequence of failure" standpoint, I think it becomes a simple decision IF Rec90 is readily available in your area:

Rec 90: Probably safe to assume that some Rec90 will either have some water in it as purchased or be contaminated with ethanol by putting Rec90 gas in tanker trucks that had carried E10 and were not completely drained first. Worst case scenario is repetitive sludge build up from continuous use of low % ethanol laced Rec90, where the corrosive sludge overloads both the Racor and on-engine filters and possibly kills the HP fuel pump, and worst case, some fuel injectors. The E-TEC HP pump is ~$150, but the injectors are $400 ea., so it could get expensive in a hurry if it were to kill injectors. At least the Rec90 octane level would not be affected. Preventative Maintenance required: Test all fuel for ethanol contamination before filling tank, and check Racor frequently for water/sludge and drain it out before it overloads filter.

E10: Worst case scenario is somehow getting enough water in the tank, via vent fitting, leaking O-ring on fill cap, leaks around sending unit gasket, or corroded holes in tank, to phase separate ALL the ethanol, dropping octane level from 87 to ~83-84 octane! The larger E-TECs (3.3-3.4L 90 degree V6 motors and all the new G2 models) have knock sensors that will detect the detonation from the bad fuel and display a "Knock Detected" warning on the I-Command gage if the EMM is not able to retard timing or enrich mixture enough to eliminate it, but the smaller E-TECs (60 degree V-6 and V-4's, and all I-3 and I-2 models) do NOT have knock sensors, so first sign of low octane fuel will probably be when detonation blows a hole in a piston! Fixing this will cost much more than replacing a fuel pump and/or some injectors! With a 4-stroke motor, you MAY be lucky enough to be able to hear the valves rattling and throttle back before it fails a piston, but ANY 2-stroke motor without a knock sensor is especially vulnerable to detonation because there are no valves to rattle! Preventative Maintenance required: Test all fuel to insure ethanol content does not exceed 10%. Inspect fuel tank to insure no corrosion holes, and inspect sending unit gasket, gas filler cap O rings and vent hose routing and fitting to insure NO water can find it's way into the tank. Check Racor frequently for water or phase separated water/ethanol. If running E10 gas, you should expect to NEVER find any water in filter bowl. If you DO find water/ethanol sludge, it's a big red flag that you may have a load of low octane fuel, so you may want to drain tank and burn it in your truck, lawnmower, etc., or at the very least add some octane booster or top off the tank with some premium 92+ octane E-10 gas!

Although this isn't a real scientific risk analysis where you'd have to multiply (Probability of Occurrence)x(Cost of Occurrence) to quantify potential costs of a worst-case failure of each option, I've concluded that Rec90 is fundamentally lower risk because loss of octane is not an issue. I know the Racor will trap water and/or ethanol sludge and it's easy to monitor that. Conversely, I can visualize situations where significant amounts of water could get into a tank of E10 without my knowledge, and the resulting octane loss could quickly destroy any engine without a knock sensor!