Piston to block measurement
Turbo Mini Forums

So iv read through everything I can find and I’m struggling to get the correct measurement.
Iv got a standard 998 a+ 1989 city e
Have flat top pistons standard cam standard rockers lifters from 998 head etc
I’m using a 12g940 head and trying to work the compression ratio out.
I can do everything apart from the piston to block measurement as don’t have the correct tool.
The block has not been skimmed and as far as I can tell the head hasn’t either
Can anyone shed some light on this?
The Haynes is not really helping either

A crude method would be to put straight edge across the block face and use feeler blades under it to determine the clearance.
Though a proper depth mic would be better and can be picked up cheap enough off eBay.

Phil.

WWW.TURBO-MINI.COM

Second that, or use the tail of a vernier but this isn't as accurate as a depth mic'.
Shane

Thanks guys
So iv done it hopefully, does this look ok
Also would you drop the comp for the turbo?
998 =249.5cc
Head 21.4cc
Head gas 3.8cc
P/b 1.37cc
Rlv 0.5 cc
Pistons are flat top
Giving me 10.50 using the compression calculator someone put on here years ago.