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8.1 lt L18

Discussion in 'Chevy Trucks' started by scottr, Feb 29, 2016.

  1. scottr

    scottr Senior Member
    Messages: 405

    Im very new to the Bow Tie engines, and this is not related to snowplowing. But I'll ask anyway. I've been thinking about a new project to build and decided to build a rock crawler. I have access to a fresh built 8.1 lt and all the controls needed to run it. ( ECM, etc) question is, what are some weak points of this engine or things to be aware of? I know it's heavy and likely not a real mileage getter. I've been researching on line, but would also like to hear from you guys that use and work them. Thanks for your input.
  2. Joe D

    Joe D Senior Member
    Messages: 605

    Define built. The cam, heads, intake are the weak points in the 8.1. Unless you already own it, go with the 6.0. For short money you can get great power out of them.
  3. scottr

    scottr Senior Member
    Messages: 405

    I followed up on this some more last night, I was told it has less than 50K on the motor, I took that as "re-built" come to find out, that's all it has on it. Belongs to my buddy who will give it to me for this project. Thanks for the info about the intake, do they tend to suck air? leak oil? This is the only reason for me using a 8.1 price.Thumbs Up
  4. secret_weapon

    secret_weapon Senior Member
    Messages: 437

    What year is the engine? Earlier engines (pre '03?) had some crank sensor issues.
    They burn some oil, so check level often.
    Any major upgrades will be very expensive $$$$. Cam and heads. The stock intake flows just fine even with an aggressive tune. Stock exhaust flows just fine too.
    I have heard of some engines having problems with eating lifters and cams but nt sure on years.
    It is not a revver, keep rpms low and use the torque just like a diesel.
    The only oil leaks I have on mine are the oil cooler lines.
    Put a 180 deg t-stat in it.
    ac delco 41-993 plugs gapped to .045
  5. Rat_Power_78

    Rat_Power_78 Senior Member
    Messages: 184

    Not as much aftermarket support compared to the 4.8/5.3/6.0 but if it were given to me, Id run it.
  6. scottr

    scottr Senior Member
    Messages: 405

    Great info, thanks for the help Guy's Thumbs Up Oh, it's an 06 vintage.
  7. Clarkmac1985

    Clarkmac1985 Member
    Messages: 30

    Throw a high torque camin it from gm. They built a HT 502 and the cam is a direct bolt in from what I read. Also most of the BBC heads for a gen VI bb wil fit them I think anyway.
  8. Philbilly2

    Philbilly2 PlowSite Veteran
    Messages: 3,797

    These are the two that I have seen.

    They are fairly bulletproof motor though. The cattle farm that I worked on years back had an 03 that had 200,000 plus miles on it. It spent very few hours of it's life without a 30' cattle trailer not attached. I always said that Chevy should have made the "Like a Rock" commercial about that truck... not a straight piece of tin on it, but it started every time and ran the dang tires off that cattle trailer...