750 Cylinder Does not have O-Rings


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Lawrenceville, GA
Anyone noticed that the BBK cylinder does not have any o-rings installed. What is the purpose of these o-rings? Could oil get between the sleeve and leak out the gasket. I would think the gasket would stop the oil. Just wondering If anyone knew the reason being using these two o-rings?
When an engine heats up, the fit of sleeve to cyl block loosens, even enough to slide out, as in sleeve replacement. The o-ring is supposed to prevent engine oil from wicking up between sleeve and cyl-block, maintaining heat transfer and preventing 'fretting', which is the inner wear of the cyl-block which reduces the interference fit 'grip'.

Disclaimer: This was a '60s-'70s Honda tech canned response. Modern methods and manufacturing may have made this moot. I've seen Loctite's sleeve grip compound, but never used it. Back then, when I bored cyl blocks for oversize sleeves, I used a little extra interference fit to ensure sleeve/cyl-block fit at temperature and heat transfer...
I'll add that the lip on the top of the sleeve is gripped pretty solid by the head gasket. I'd guess it's pretty safe from shifting even without the o-ring.