71Buickgransport!

Building LM7 What kind of numbers do u need after sonic testing cylinders to be safe after boring whats max thxx

Che70velle

iTrader: (6)

It’s always a mixed bag when sonic testing blocks. No two blocks will hardly ever be the same, and you’ll usually end up with an odd cylinder that’s a lot thinner than the other 7. Opinion takes over here, because the science just isn’t there. Lots of variables involved also, such as power level, usage, street or race, power adders vs. N/A, etc. But for a starting point and to make this a discussion, you usually want .140+ on thrust sides with a mild N/A build. I’ve seen .100 work just fine in N/A builds and last for years, but most builders would recommend much more wall on thrust sides.

71Buickgransport!

Thank you Scott ill see what the test shows

LS1Formulation

iTrader: (13)

I've heard as a general rule on iron 5.3's, that they can be bored out to 3.905" if the block doesn't have issues with core shift. I'm not sure on all aluminum 5.3's, but with my LH6 block, it also can be bored to 3.905".

71Buickgransport!

OK thxx got to get the test done core shift in cylinders or by lifter bores

LS1Formulation

iTrader: (13)

Core shift affects the whole casting, but you're going to be concerned with the cylinder bores. You might have a block with .250 on one side of the bore and .090 on the other. Obviously that's a bit exaggerated, but you're looking for similar numbers across the bore from each other.