Originally Posted by
nitroexpress
As I understand it, there is .3mm built in clearance. So you are running a total clearance of .7mm. This is on 25% nitro.
On the MM site, it states that on 20%, he runs one .1 shim. This would be a total clearance of .4mm. This would be after break in. Anyone running this?
I'v only just started playing with shimming, so still new to it.
My 1st MG66 lasted 11.5 months with 62ltrs throu it before the ORIGINAL rod let go (did not change to 2nd rod on purpose as we were doing an experiment) main bearing didn't need changing untill the 40ltr point and I didn't change the shimming either from stock and still got great performance out of it.
This 2nd MG66 I decided to remove just 1 .1 shim to see how it goes and found it perform like its on 30% so I stopped there.
I feel once I find "what works for me", why change it !
I
may try removing another .1 after the scheduled bearing and rod change.
I can only post based on my own experiances, I do not speculate or assume what others do or why !!
I'll let MM elaborate on his shimming guide.
But yes, so far I have .4 shimming, not .4 head space.
I don't understand the head space thing, I just know what shims I'm running.
That is why this is such a good helpfull thread, because the people helping only comment on what they have had experiances with.