Folks,
Churchie and I are going to rebuild our LS-1 next weekend, and we've been driving everyone nuts asking about what we should and shouldn't do to our LS-1 donk.
What dropped out of the conversation were some facts behind the "known LS-1
oil burn problem" (thanks to Boxhead and a couple of others)
Older LS-1's have an
oil burn problem primarily due to the rings they had fitted at the factory.
Apparently the standard pistons also (they have quite a short skirt) tend to rock a little in the bore when the engine is cold. This can cause a "piston slap" noise that is audible when the motor is cold, and goes away once the pistons warm up (and thus increase slightly in size). In cars that have done a lot of kms this can remove the hone on the bore and make the bores slightly out of round, thus creating a gradually worsening
oil burn problem.
Holden's solution to this is to replace the pistons with teflon coated ones, that are the same size as the original...but due to the coating - don't make the noise.
So the moral of the story with an LS-1 with an unknown history is:
1. defintely replace the rings
2. definitely check the bore to make sure it is not "out of round" and if so hone it, then measure and if outside tolerance - get new pistons
3. if it is still round and inside tolerance, get new pistons, but only if you don't want the start up noise. (I figure we're not going to hear it over the exhaust anyway !)
4. Do all the other normal things you do when rebuilding a motor.
Of course if this is your second motor, and you already have rego....then ignore everything I've just typed and go nuts with some nice forged puppies and a cam !!