.....Need info/Help

[OrangeBlk08Busa]

Doin some R&D $$$ on all motor and turbo and need your advice...and hopefully i'll know what direction i will be going.

option 1
All Motor Block ...... APE exchange package...1441cc
On this exchange package.....are the pistons and rings usually pre-fit'd sized for each dedicated cylinder?



option 2
Turbo route .........Stock Bore JE's 8.5 + spacer.080 and 1 gasket.090
08 busa with 0 miles on tach.....But,started twice at garage and of course factory run.
Can i fit stock bore Turbo JE's into....... my stock block with no honing since block is still New and rings not broken in yet ? .....or would i still need to hone/clean up bore?

What would be best ring end gap for both 1441 na and stock bore turbo pistons?

Thanks

 

[Mr Bogus]

end gaps vary with "bore" more bore, more end gap.. check with the ring maker for specs on a particular application.. I run gapless rings when ever possible in the second groove.

Rule of thumb (well on my big motors) is .004 per inch of bore

 

[OrangeBlk08Busa]

Thanks! MR.B

 

[Area-51]

I agree with Mr. B to an extent. He is correct most use a general rule of thumb of .004" clearance per every 1.00" of bore diameter.

1441cc NA set up would be .010"~.012" top ring, .012"~.014" second using JE rings. Yes, being the amount of time on the engine you can forgo the cylinder deglazing with a brush hone and just go straight to a detergent wash of the bores and install the new pistons / after you have clearanced your rings.

1441cc Turbo set up .012"~.014" top ring, .014"~.018" second ring groove. The added clearance is to deal with the heat to keep from the compression ring tabs from butting, and additional clearance on the second to keep from lifting the top ring and breaking it's vital seal. Same holds true on a super charged application. You do not want to run a total seal gap less ring as a scraper in either application from the testing results I've seen. The gap less rings should only be used in the top groove (compression ring groove only).