Results 1 to 1 of 1

LSx motor purpose build for E85

This is a discussion on LSx motor purpose build for E85 within the Internal Engine forums, part of the LSx Technical Help Section category; Anyone know of a combination of LSx, LS1, Gen III heads, cranks, pistons that will yield 14:1 or higher compression ...

  1. #1
    Junior Member
    Join Date
    Aug 2006

    LSx motor purpose build for E85

    Anyone know of a combination of LSx, LS1, Gen III heads, cranks, pistons that will yield 14:1 or higher compression ratio for a E85 only motor? I want to try to mix and match stock or inexpensive components to evaluate PCM programming and a few different compression ratios before I build the final long block version with "good" parts.

    Anyone built an LSx motor to run solely on the 105 octane ethanol fuel?

    According to this article, E110 was used in a 19.5:1 compression ratio with good results. If this is to be believed, E85 at 14:1 ought to be childs play.

    As far as the rest of the fuel system, 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.

    What I am looking for is someone that has 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. 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.

    The GM Flexfuel fuel pump will likely be required as it addresses the fact that alcohol is electrically conductive and is not a lubricant. Dino fuel is non conductive and is a lubricant.

    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. It 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 14.5:1 compression ratio so I can get busy shaking out the computer reprogramming changes.

    Can anyone help me with the mixing and matching of basically stock engine components including cylinder bore, crank stroke, head volume, pistons, and rods to achieve something north of 14:1 compression ratio? I am not looking for big cubic inches, just big compression for a mule for PCM programming work.
    Last edited by Pecos Pete; 08-15-2006 at 01:41 PM.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts