1992 Miata, LS1, then LS3 swapped

[GySgtFrank]

Originally Posted by mazpower

Interesting...I'm running a SLP front dampener on this build cause its keyed, as is my crankshaft and I wanted solid timing marks (LSx engines don't have keyed pullies or cranks from the factory, no timing marks either). The engine is pretty damn smooth through the rev range. I've heard that spec clutch assemblies can be out of balance though, I wonder if that contributed to it? I've been running the same flywheel/clutch combo since the beginning and this is the first time I've had this happen.

It may not happen again, who knows. The six we were running had been internally balanced when the engine was built and it ran very smooth. Had the flywheel and clutch rebalanced too, didn't help. One of those weird things that you couldn't really tell just listening to it. It may be a balance issue or like you said it may just be the bolts, maybe something else. Have to see if it holds this time.