NOx isn't measured on MOT is it?
No, but your biggest problem will be knock. Yes, the engine has knock sensors so it can theoretically cope but who knows how much timing adjustment the ECU will allow before it throws in the towel and goes into limp-home? Or maybe it will just lob in as much correction as it allows and yet still hole a piston?
Compression ratios this high are extreme even in tuned engines, and those generally have more aggressive cams which result in less VE in the medium rev range where knock can be a killer - meaning that the effective CR is lower until they hit high revs. They also generally have forged pistons at this level so are much stronger and able to cope with a little knock.
I think trying this with an otherwise stock setup where you can't adjust fuel and spark is asking for trouble - unless it has been tried before with success. It's an easy upgrade (just like 3.0 cams in a 2.5) so if it worked, people would be admitting to have tried it
(just like they do with 3.0 cams in a 2.5). The silence speaks volumes, IMO!
It would be a real shame to go to all the trouble and expense of a top end rebuild only to find out you've got an engine that doesn't run.
Kevin
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Topic: Elite top end rebuild (Read 2747 times)