Generation IV Internal Engine - LQ9 max bore size

Will the LQ9 cast iron bore block go out to 4.065? Has anyone sonic checked one bored to this dimension?

Yes. There are guys going out to .090. As far as sonic checking at this dimension, I don't know the answer. I'd like to know myself. I'm going .065 with my ly6. I WILL sonic check mine when it's done. I can tell you that the gen 3/4 blocks are a far cry from previous sbc castings when it comes to quality. You just won't see the core shift issues that we used to, at least with the iron blocks.

This subject has been thoroughly beaten to death. Some simple searches should bring plenty of info.

I have sonic checked a 6.0 block at 4.080 it was at the minimum safe thickness, issue is its only one section of the bore that becomes relatively thin, not the whole bore.

4.030 max bore size for power adder
4.080 max bore size for N/A

Fraser

Thanks for the input. It may seem like an old issue but things change all the time. I retired from GMPT and change is constant. Can't spend $$ on old info. I need to decide whether to go LQ9 or LSX for my new build. I'd like to go 4.100 bore and 3.750 Callies stroke for 396 inches with the LSX block or 4.065 bore with a 3.750 stroke for 389 inches with an LQ9 block. The only benifit with the LSX is future rebuilds to bigger inches. Thanks for the feedback.

I trust Fraser@AES on his recommendations on the max bore for an LQ block, but check out this thread. It has a guy going out to 4.125 bore on an LQ block. Post 29

http://ls1tech.com/forums/generation-iv-internal-engine/1026866-how-big-can-you-bore-6-liter-block-2.html

If my calculations are right based on when I sonic checked an LQ9 block at 4.080, at 4.125" the cylinders would be down to .080" wall thickness, i'd like to be over .100 at minimum.

Fraser

Thanks for the input. It may seem like an old issue but things change all the time. I retired from GMPT and change is constant. Can't spend $$ on old info. I need to decide whether to go LQ9 or LSX for my new build. I'd like to go 4.100 bore and 3.750 Callies stroke for 396 inches with the LSX block or 4.065 bore with a 3.750 stroke for 389 inches with an LQ9 block. The only benifit with the LSX is future rebuilds to bigger inches. Thanks for the feedback.

If you really want a bore that size the smart thing to do is sleave the block. I would never bore one more than 60 over.

good info to know....thanx and GOD Bless, Rob ;)