Exactly, ANYTHING you change above the piston will have an effect on the final compression ratio, I usually CC the head and piston dish then calculate the actual ratio (been lazy since finding a calculator to do it ;))
I think in your application the stock IC just isn't going to cut it and is heat soaking badly :(
Personally I'd Bore and Hone and go the next up piston size.
83mm = 3.267" x 4 thou = 13 thou then add 4 for 17 thou top gap (don't forget to add in the new oversize bore)
83mm = 3.267" x 5...
I do the old school 4 thou per inch of bore top and 5 per inch 2nd and if I'm running the engine hard I add another 4 thou to the total and so far so good.
You appear to have caught it right at the start and it doesn't look too bad as far as closed gap damage goes so the comp figures would...
Damn....
Come on guys "doesn't look that bad" WTF are you smoking... :nono:
Dave: My educated "guess" after trashing my 7M in much the same way is it's a combination of lean and high AIT that's ran the cylinder temps high enough to close a couple of the ring end gaps :(
1: Yes (assuming you're NA you have to remove the TB)
2: Sorry NFI RHD here so we didn't get the monkey motion linkage garbage
3: It's the "BHG" light aka "Bird Has Gone", also might need to top up the Rad Recovery bottle.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.