So, I was digging around about bores for the CA and came along these two articles about max cylinder bore for the CA. Now, as we all know, max bore isn't very far for the CA, maybe 84.5 if you got a good block. What has interested me more is the topic of core shift. For those that don't know, it's basically when the molding of the cylinder bores and block get messed up during manufacturing process and the mold is moved (a careless worker, vibrations, etc). One of our down-under brothers was saying that this is a common occurrence with early CA blocks.

This pertains to max bore because if you have core shift, one of your cylinders will have a thinner wall than the other cylinders, not allowing further boring. Has anyone else seen evidence of core shift on their CA? Also, it got me thinking, that maybe the CA is best suited to be a sleeved block. I haven't seen anyone use sleeves on any engine build, as it's mostly an American thing to do on V8s or domestic cars, but it would be a really good option for the CA, since boring it to a large degree is impossible.

I suggest reading through these topics from our Aussie brothers.
http://sxoc.com/vbb/showthread.php?5062 ... ultrasonic
http://sxoc.com/vbb/showthread.php?3895 ... =84mm+bore

SXOC is based in the UK. They're the only people I've heard talk about core shift issues. I suspect (but can in no way confirm) that this was an issue associated with the 4 port European delivered blocks. The early 4 port heads also had issues with valve deformation that the 8 ports never had issues with. I can't find any information on this, but I've always wondered if the 4 port engines weren't manufactured in Japan, and as such, had poorer QC initially. The valve issues and core shift issues are only associated with early production engines.

float_6969 wrote:SXOC is based in the UK.

Lol! I always thought they were Aussie since they used similar language, like bonnet, boot, things like that. But thinking about it, the UK has that language too. Probably because their language is very much alike since Aussies are just people who were outcasts of Europe.

No worries. There is another big forum called hardtuned that's based in Australia. The CA is a very popular engine down there and they have a BUNCH of big builds down there.

don't see much need in boring any more than required to clean up
These bores don't "wear" well either imo. I've found uneven ridges in a few. Majority of mine r 4 port
Read of lots of aussie 'bent crank' threads too
The CA18 definitely aint no DSM 4G63 for instance... where folks have (and still) beat their original long blocks into crazy numbers

Sleeving the CA is not an issue, but the cylinder spacing is not very big so it kind of limits the bore anyways.
Cometic makes gaskets with whatever bore you want so that is not an issue.
I haven`t measured any CA blocks yet (im an UT (Ultrasonic Testing) operator.
Would be interesting to measure a few blocks, i have alot more than "a few".

Well I'm at 84.5mm on this build, so I guess I'm going to find out pretty quickly how much of a concern it is on this JDM block.

I remember seeing some NISMO 85mm pistons a while back, but they were for a naturally-aspirated CA18 engine.