LS-1's and oil burn/piston slap

[hewey]

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 !!

[Philm]

HI Hewey,
You could put all that piston slap and oil burn s*#@ behind you and put in a ford engine!!

Seriously, do what you can afford. I would only say that while it is out of the car it is easier to do these things.

If the bore is out of round I would get the block machined and fit new bearings, oversized pistons and rings etc.

I have mikes bore gauge here, I would ask Mike if you can borrow it and I will get it to you.

I have finished my motor and hopefully put in in this week end. I have some pics in my gallery.

Phil

[G1947]

Gee I must be the luckiest bloke in Oz.
I keep hearing all these horror stories about oil burn and piston slap, let me tell you the other side........
My wife bought a new VT Series 11 SS Commodore in October 2000, first model with the LS1. The car had 10k's on the speedo when we test drove it. Engine was noisy on startup when cold, sounded like lifters. Traced to noisy belts on the early engines, all engine pulleys and belt changed, no more noises.
Dealer serviced every 10000k's, we always complained about drive train noise, and told "that is normal for these cars". At 90,000, transmission was slipping, replaced under warranty. Then, with the noise from the tranny gone, you could hear the diff.
Diff replaced under warranty at 95,000 k's.
The car is now my daily driver, (as she has bought herself an MX5) and has 286,000k's on it. It has had new pads, front struts, rear camber kits etc, but apart from being serviced every 10,000k's, the engine has not had a spanner on it. It used no oil up to 150,000k's, and even now, I only add 1 litre after 6-7,000k's, between services.
The only problem I have now is when I book it in for a service, I am told, "Our service schedule only goes to 200,000, we don't know what to do!"
I sure hope the LS1 I buy for my Cobra is as good.

[G1947]

Oh, I forgot to add, I am a tried and true Blue Oval man, lots of Ford V8's over the last 30 years, this is the FIRST "Hold On" I have ever owned.
Regards
Garry

[Rebel1]

Gawd, You're gonna rebuild an LS1?. I thought you just threw em away like an empty stubby, melt em down and make another one. .

Get one of those LS2 thingys. ....

[HSVREDSLED]

This is very funny,

In the last minute I posted this reply on another site.

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Personally I think it is the case of the silent majority versus vocal minority. I would like to see a survey as to who has had dramas and who has not.

As for me...chalk one up for a reliable motor, 85,000kms in 3 years. No slap, no oil issues.

cheers

Sled
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I would still like to see a survey done.......