99 vette/VR4/Talon/jigster 750

[Superluminal]

I'd consider improperly seated thrust bearings causing crank walk and engine failure something "mechanically wrong" with the engine

Some motors, when newly introduced, tend to have problems which are later fixed during the production run. Even the LS1 suffered from piston slap and oil consumption during early production years (i.e. '97-98). Just like the 7 bolt 4G63, the motor was revised and updated with better mechanical components. The 7 bolt motors that come in the EVOs are pretty durable, as long as you don't run ridiculous amounts of boost on the stock turbo without supporting mods.

But yes, the early 7 bolt motors were all a ticking time bomb if not fixed. Most of these guys, usually went with an older 6 bolt if they decided to do an engine replacement.

[Wesman]

Some motors, when newly introduced, tend to have problems which are later fixed during the production run. Even the LS1 suffered from piston slap and oil consumption during early production years (i.e. '97-98). Just like the 7 bolt 4G63, the motor was revised and updated with better mechanical components. The 7 bolt motors that come in the EVOs are pretty durable, as long as you don't run ridiculous amounts of boost on the stock turbo without supporting mods.

But yes, the early 7 bolt motors were all a ticking time bomb if not fixed. Most of these guys, usually went with an older 6 bolt if they decided to do an engine replacement.

Piston slap was nothing more than a result of different expansion rates between dissimilar metals and did not affect performance or reliability whatsoever. The oil consumption issues were a result of a poorly designed PCV system which was later revised. Neither were mechanical failures and neither resulted in any engines blowing up.

[+stroker ace]

You consider improperly seated thrust bearings mechanical,but don't consider pistons flopping around in bores to be.If nothing else you are always predictable.

[big hammer]

You consider improperly seated thrust bearings mechanical,but don't consider pistons flopping around in bores to be.If nothing else you are always predictable.

one issue cause catastrophic engine failure. one caused noise.

[Wesman]

You consider improperly seated thrust bearings mechanical,but don't consider pistons flopping around in bores to be.If nothing else you are always predictable.

You obviously know nothing about engines or engine clearances.

The earlier LS engines were designed to allow the pistons to expand and contract in their bores a certain amount due to the different expansion rates of the cylinder liner metal and the hypereutectic pistons. So when the engine was cold, the piston to cylinder wall clearance was larger, making it audible. When the engine warmed up, the clearances became tigher, and the noise went away. It was in no was detrimental to performance or reliability. The pistons were in no way just "flopping around in their bores"

The 4G63 has inherent design flaws that caused them to blow up. Piston slap was a noise complaint, not a performance complaint.

[+stroker ace]

Wesman I've probably forgotten more about engines then you'll ever know.It's kinda funny there is a thread on the j body forums where you said you liked DSMs.What happened wes you get smoked one to many times by one.I won't comment any more because like all the threads involving you it will it will get closed.PS don't change wesman we love you just the way you are.

[Wesman]

Wesman I've probably forgotten more about engines then you'll ever know.It's kinda funny there is a thread on the j body forums where you said you liked DSMs.What happened wes you get smoked one to many times by one.I won't comment any more because like all the threads involving you it will it will get closed.PS don't change wesman we love you just the way you are.

Considering you think piston slap only on cold starts is as bad as crank walk blowing up and entire motor, I highly doubt that.