rebuilding engine

[97cutlas$upreme]

my car has 135k miles on it.. im planning on buying a gtp sometime next year maybe around june or july.. if this doesnt happen im plan on getting the 3100 rebuilt. heres the question.... does any body know of a good engine master kit with pistons? and also whats the maxium recommendation on going over on pistons? i was think of going.50 over would this cause any problems or weaknesses?

[jackal2000]

do you mean .050? i would say thats about the max.

[bracketracer]

Max safe overbore

I will be picking up my built shortblock later this week, and it was bored over .060 (a 1990 Gen II 3.1 MPFI). My engine builder felt this amount would be safe based on the condition of the block I bought.

This is as big as it can go safely without being resleeved though, from what I've been told. I would have to get another block if I ever want to rebuild in the future, or go bigger. I would end up using my original factory engine since I will be keeping it as a backup.

If you plan to keep the engine for awhile longer, or it's in a daily driver that you want to keep using, you probably don't want to overbore it to the max. If you only overbore as much as you must to "true up the cylinder bores," it will leave you more room for a future hone or overbore. Once you go as big as I have, you're stuck!

Hope this helps.

[97cutlas$upreme]

yea sorry thats what i meant .050 so being 135k on it im pretty sure i could still use the same block right? i guess it just depends on the condition right?

[CNCguy]

I assumed the .50 measurement was metric or .020 inches. It seems most pistons come in .50mm or .020" increments like .020, .040 or .060 oversizes.

[jackal2000]

yea sorry thats what i meant .050 so being 135k on it im pretty sure i could still use the same block right? i guess it just depends on the condition right?

unless it has a crack in it or something you should be good to go with that block. bore and hone away!