E85 engine tear down

Eric68 · Post by **Eric68** » Thu Oct 09, 2008 4:59 pm

Thought you guys would like to see this. After two seasons on E85 I took the heads off and started to disassemble for inspection before it gets sold. Pistons are probably the cleanest I have ever seen on tear down. Heads have light / normal coloration (as far as I can tell).

Engine is SBC 4.145" bore x 3.800" stroke with SRP forged flat top pistons. This is a solid roller cammed engine that is 11.4:1 compression and has been run almost exclusively on E85 since spring 2007. It did have 6 months run time on gasoline before the switch. I was surprised at how clean everything is -- I did not wipe or clean the pistons before taking these pictures.

There was no ridge at the top of the cylinders, and no scoring or other signs of a lubrication problem in the bores. Engine has 250+ quarter mile passes on it and 15,000 street miles since it was last freshened up. I cruise on the freeway at 3400-3600 RPM and do NOT take it easy on this thing.

Dodge Freak · Post by **Dodge Freak** » Thu Oct 09, 2008 5:18 pm

I would have guess there be increase wear since alcohol is "dry"

Unkl Ian · Post by **Unkl Ian** » Thu Oct 09, 2008 5:56 pm

Notice how the carbon is biased towards the exhaust side.

Brian Rock · Post by **Brian Rock** » Thu Oct 09, 2008 9:37 pm

Eric, what are you replacing the 410" with?

Unkl Ian · Post by **Unkl Ian** » Thu Oct 09, 2008 9:39 pm

Unkl Ian wrote:Notice how the carbon is biased towards the exhaust side.

Do the chambers have similar coloring ?

Eric68 · Post by **Eric68** » Thu Oct 09, 2008 10:26 pm

Here is a picture of the chambers. These are the # 5 and #7 cylinders which match up with the pic of the odd cylinder bank above. They look a little darker . . .

Brian, building a 427 SBC. Spec'd for E85 (compression 12.8:1, 260* @ .050 cam, new heads, etc.)

Truckracer · Post by **Truckracer** » Fri Oct 10, 2008 10:23 am

Looks like you had a good air filter setup on the engine.

What oil did you use?

jdavis · Post by **jdavis** » Fri Oct 10, 2008 11:26 am

Looks pretty much like one I just got done tearing down for head work. I dare say the one I just tore down was a little bit cleaner even, but it had nearly no time on gasoline at all.

Might want to smooth that sharp edge on the exhaust side of the chamber while theyre off too?

Looks like you did very nice clean assembly work. Now get that 427 together

. How are you coming along on that project?

Eric68 · Post by **Eric68** » Fri Oct 10, 2008 6:46 pm

Thanks -- it's hard keeping things clean in the garage but I do try, not exactly a clean room.

I use Mobile 1 10w30 almost exclusively. Probably not what most here would recommend, but I've had good luck with it. I use a K&N and never run it without a filter.

Got the 427 bare block back from the 'sheenist today. Had to go to an X bearing because the mains were too tight (my Plastigauge was pretty close to his dial bore ind BTW). Dart seems to like to set up their Little M a little tight in the main bore and lifter bores. Time to start assembly.

BTW Dodge Freak. E85 being 15-30% gasoline isn't exactly as "dry" as you would think (if you're thinking methanol). From what I am told the gasoline component besides helping with starting also helps lubrication.

RL · Post by RL » Fri Oct 10, 2008 8:22 pm

It might be the picture but is there any cross hatch left, The bore kind of looks shinny

I suppose you won't see much wear in 15K are the valves coming out to see what the seats are like

Eric68 · Post by **Eric68** » Fri Oct 10, 2008 10:16 pm

Cross hatch is still there, much lighter than when it was assembled, but still there.

Actually, I don't think it's coming apart much further (at least by me) -- Have a buyer for both the short block and the heads.