Ma12 max head skim.

[bikepmist]

Hi there,have the high com k10 engine,putting ma12 head on ,need to know max skim in mm i can take off
i am no good at formulas for cr,so if anyone knows in mm to skim it would be great!,thanks guys!

 

[frank]

i had 3mm skimmed off iirc, but that is quite extreme, and needs cam re-dialing and the belt adjuster on full, its probably over 11:1 c/r at that

 

[bikepmist]

Hi Frank your up early!,busy man i suppose?,how did it run with 3 mm skim?,i am just worried with the higher compression pistons, that is less of a "dish" on the tops,
that i might have piston to valve issues?,thanks for the reply by the way!,you are a good man and always willing and helpful to give advice,which i and other people
really appreciate!! thanks again!
B p.....

 

[frank]

nah, pissed the bed mate
mine was a stock ma12 daily driver (dished piston) with a lightened flywheel, and it was quite nippy
the stock 9:1 is pretty low by modern standards, so you need a decent skim really
and any p 2 v contact will be near the outer edge of the piston on a hemi head, (so dish is irrelevant tbh) its just duration on the cam you have to worry about

 

[frank]

if you are running flat top pistons they will have raised the c/r about one and a half points i guess (10.5:1 ?)
so a 1.5 or 2mm skim maybe ? there are some online c/r calculators we tried on here a while back

 

[bikepmist]

Thanks once again Frank for your time and help!,i hope the bed wetting problem dries up,i do not want to have a mental picture of you in my head
wearing "a nappy"!!,lol...... B p