LSx built for 105 octane E85

What I am looking for is someone that has experience or information building a LSx, LS1, Gen III that's purpose built to run E85. Purpose built to run 105 octane alcohol (ethonol) ONLY. I am not looking to include the Flexfuel feature, just run E85 all the time. That's the important thing. An engine that's built to run alcohol can scream, but it has to be optimized for the fuel. Larger injectors, timing, higher compression, maybe even the camshaft should be set up to take advantage of the cooler burn and increased octane. Basically this stuff is just alcohol with enough gasoline thrown in for cold starts. It is racing gas.

www.hybridcars.com/blogs/hyview/more-from-ethanol

The ECM programming will take some effort to get right. I know this. I understand alcohol burns at a different rate than gasoline, so the timing will be different. I also understand that the cylinder pressure from Alcohol lasts longer so a larger rod/stroke ratio will help exploite this. I also undertstand alcohol also burns cooler than gasoline, so it takes longer to light off the catalytic converters. O2 readings will likely be different. Wide band O2's may be necessary. Making it E85 specific simplifies things a bunch, but this will also be breaking new ground in uncharted terratory.

I am just looking for a straight forward combination of LSx parts to achieve at least a 14.5:1 compression ratio so I can get busy shaking out the computer reprogramming changes.

If I use a;

6.0 block => 101.6mm bore (4.000")
6.0 flat top pistons
4.8 crank => 83 mm stroke (3.268")
4.8 rods => 159.38 mm (6.275")
LS6 heads => 61cc
.040 head gasket height

I end up with a rod/stroke ratio of 1.92:1, a calculated static compression ratio of 11.98:1, and a calculated lower piston speed due to the short stroke that will allow 7500 to 8000 rpms on stock length 4.8 rods.

www.race-cars.net/calculators/compression_calculator.html]

What works best to get the compression up even higher? How much can the heads be milled? I know flat top pistons are best for flame propagation, but are domed 6.0 pistons available?

Anyone done something like this yet?

I want to end up with something like Westech's 302 motor, but optomized for E85.

http://www.camaroz28.com/articles/302camaro/index.shtml

Just incase you didn't know this, E85 eats away at plastic and alluminum. The entire fuel system will have to be stainless steel.

Thanks for the concern though, but I believe GM has this covered. All I have to do is gather up GM fuel system components used on their Flexfuel E85 ready vehicles. I believe GM started this in 2002. Look for the yellow gas caps -

http://assets.cobaltnitra.com/teams/repository/export/0ba/71e606c22100487b50003ba76d6c7/0ba71e606c22100487b50003ba76d6c7.jpg

http://www.gm.com/company/onlygm/li...llow/index.html

Anyone here have experience or information running E85 in an engine that's purpose built to run it. Purpose built to run 105 octane alcohol (ethonol) ONLY. I am not looking to include the Flexfuel feature, just run E85 all the time.

you think that rod will hold up to 8,000rpm and 12:1cr?...I dont..well..not for long

What works best to get the compression up even higher?


PUT A LONGER STROKE CRANKSHAFT IN IT...... More cubes is the easy way to get power and compression. A stock crank from a 5.3, 5.7, 6.0 or 6.2 will work MUCH better.

I might be the only odd ball out there who would put a 3.5" stroke in a LS2 block to get a motor that is between a LS1 and a LS2 for cylinder head testing purposes... it's a long story but if you can throw more stroke in there DO IT.


How much can the heads be milled?


LS1 castings can easily go .100" LS2/6 castings might be a little bit less



I know flat top pistons are best for flame propagation, but are domed 6.0 pistons available?


Yes, Diamond has domes and they can make you custom ones as well, which is what you will need if you stick with this short stroke, long rod deal.

Flat tops and a dual quench chamber like a Dart or LS2/6 head will work better than a LS1 or 5.3L truck head.

Bret