CJM Report: Effects of E85 after 3 years?
 

Last month I removed my fuel system to upgrade to the CJM S2SE fuel system and a larger fuel pump so that I can go ahead and turn up the boost and push the stock engine a little harder.

This gave me the exclusive opportunity to examine the effects of long term E85 use on the 370z.

Since switching to E85, my car has only run E85. In the 3 years there is only a single exception of one time when I pumped 3 gallons of 93 in the tank to extend my range to the next E85 station. My car was stored winters with E85 in the tank. No special precaution taken at any time, not even when driving the car again after winter storage.

This over 40,000 miles, and 2 years 11 months of straight E85. The car is 60,000 miles now.

I will let you come to your own conclusions while mentioning my findings. Please note that this is a visual inspection. Due to the appearance and function of the components, I did not deem it necessary to send anything out for flow testing etc to measure exact performance.

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Pump module looks great from the outside. The factory hose left in there along with the CJM fuel pump install kit components are all looking good.


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Everything that fuel travels through was pulled off the car. The inside of the fuel tank looked perfect, good as new. So did the factory fuel pipe (not shown).


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The Aeromotive pump which is "not rated" for E85 looks the same as when I put it in.

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Hard to photograph the internals but everything that could be seen in the inlet and outlet looked good as new. This pump was just installed into a different car to continue its life as it has continued to perform flawlessly and quietly.


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This stuff is a little bit of a mystery. Hard to say where it came from. It looks like pieces of plastic or rubber, but when trying to remove, it was very much like a tar and smeared on the plastic and was extremely sticky.


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Everything I could see in the injectors looked great and clean.


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The fuel dampers looked slightly questionable. I cannot say if this is just some junk that got in there, or if something inside them was starting to come apart. It looked similar to the tar in the pump module. I went ahead and replaced them with fresh ones.


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The rails looked good as new anywhere I could get light and line-of-sight


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Injector outlets looked clean


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My lower intake collector showed no signs of corrosion. My intake ports also looked very nice. My car has never had any sort of PCV catchcan or anything... ports look great. I would figure the E85 has been keeping them clean.

So as far as my conclusion... I have no idea why people are so afraid of E85 damaging everything! So maybe the dampers were damaged? Hard to say for sure... but even if they were, thats a cheap price to pay. I have seen other vehicles that developed some white residue and corrosion. So far, with my findings, I have to say that I believe their troubles were caused by an extra factor. Perhaps their local E85 station is storing it wrong? Or perhaps their local supply has some additional compound in it that is causing the problem?

Some additional afterthoughts:

The fuel filter inside the sending unit looked OK although it was pretty dirty. I had to cut it out to do the Walbro 400 pump install, so I had a really good look at it. I guess I cant compare it to a gasoline 370z filter of the same mileage right now, but I do believe it looked dirtier than average. The paper filter, which many say is not compatible with E85, held up just fine and was not compromised or breaking apart.

Another thought towards the corrosion issue... I do not have an E content gauge to know how potent the ethanol is that I am putting in the car. I am told by those with gauges that its usually in the mid e70s. At my local station, a friend recently told me he got E77 when he filled up there. Perhaps people who are having corrosion issues are getting higher concentration of ethanol? I am unsure how potent the mixture typically is across the country.

Charles, Did you take a spark plug out and look at your piston heads? When I pulled mine off my car at 9,000 miles they had a thick layer of carbon on them. After I soaked one with ethanol due to a bad injector, the carbon started "melting" away. I am very curious to look at them again after I put on some miles.

The reason behind the melting is that I put a weld rod into my cylinder to find TDC for a leak down test and when I looked into the soaked cylinder you could see where the rod had been sitting. It was a round spot that was copper colored. I thought I had a chunk of something in there so I freaked out. After I tried with a magnet to get it out it became bigger and bigger till I realized it was carbon just getting pushed around.

I will take a peek in there soon and see how it looks! I expect that my pistons are nearly totally clean based on what I have seen with other vehicles.

I expect that your carbon buildup is from before you ran E85, and that the E85 will clean it away over time.

How many miles do you have on E85 now? If you already told me on the phone previously, my apologies.

Yes the carbon buildup is most definitely from before. I put 0 miles on when I flooded the cylinder with E.

Right now I have maybe 250 miles on the car running 68% corn blend.

Nice review and input.

It's hard to come by here in Maryland as there are only a few public stations that carry it, all of which are 60+ miles from my location. I went the direct-port methanol route since it was more feasible option for me.

Is this car daily driven? The reason I ask, they mention E85 sitting too long in the tanks causing condensation issues. I wonder if this is a reason why the popularity isn't as high with gas stations and stricter regulations than 93 pump gas.

Thoughts?

good to know. Kudos for for showing the way!

My car is mostly daily driven. But it does sit for a couple months during winter. A couple times a year I will drive something else for a week or two when I am sick of driving a loud bumpy car with difficult clutch.

What you bring up is similar to a conversation I had with a friend who builds GT-Rs in the area. He has seen a lot of E85 damage. We concluded that it might be possible that, while my car does sit around here and there... the GT-Rs are generally much more prone to sitting for several days or weeks more often between driving sessions. The more exotic a car is, the less often 99% of owners drive them. So perhaps what you mention... the sitting and condensation is the gateway to corrosion issues with E85, and that my car just doesnt sit frequently enough to do the damage.

I DRIVE my car. More than anyone I know with a highly modified vehicle. The week that I took it out of winter storage this year, I put 1100 miles on it in the first 7 days. The next week was 800 miles.

I may be able to contribute my faulty injector to E85. I had those in my 350 running E and when I took them out I just threw them in a small box and left them in my garage, which is where they sat for 9 months.

Alcohol does evaporate extremely quickly. But if it was trapped in the injector I don't know how it could have. So it may have just sat in there slowly deteriorating over time.

Those injectors were pulled out of the 350 in perfect running condition. After I put them in my 370 one was seized and the others sounded like hell. So loud that I thought I had valve tap and it idled like garbage. Not because one cylinder wasn't firing either, the engine was stable. Ordered a new set and it ran perfect and smooth.

Charles, when do you plan to pull a plug? I might check mine over the weekend.

Is that rubber grommet still in the 370 pump somewhere? Mine took a dump on me in my 350 and I had a few pieces of it left over on the bottom of the housing.

I can pull a plug sometime next week. I am mostly out of the shop this week.

The 370z doesnt use a grommet to seal the pump to the housing if that is the grommet you speak of. The 370z has a nylon or teflon hose pressed over the pump barb.

This makes me feel a lot better about running e85 in my setup. Mind if I crosspost this to the BMW forum since most of us are TT there and run e85?

A little off topic, but would there be any performance benefit to E85 on an NA engine? Just curious as I see no one thats really done that here before? I just see all you boosted guys switching over (which i know is to help with safety as well)

Could have been corrosion from the fuel lines? They say high ethanol content likes to break down and corrode rubber. A lot of people upgrade their fuel lines to stainless braided to help with this issue.

to be honest I didn't know it had anything to do with safety. I use it cause its higher octane and cooling properties. Paired with my tune it's amazing how much of a difference it makes. It also allows me to boost at 22psi :D

but to answer the NA question:
This brings up the idea that just like adding high octane race gas to a stock motor on stock timing, you will see little to no gains, the same is true with running E85 with no tune. In fact, you can actually lose power not to mention it takes 20%-30% more E85 to reach stoich so I would doubt the car would idle much less run on E85 without a change to the cars ECU to tune for it. E85, like race gas, is for those of us who are pushing cylinder pressures to the limit of detonation. What “potentially” makes it better than race gas is the price. Currently E85 sells for around $2.75 a gallon.

source: E85 Vs Race Gas | Cooling advantage and tuning Ethanol