If you run the Mahle 906 pistons with the 67S heads you will be around 9.7/1 provided that the heads are not decked and it didn't have too many valve jobs. That is without head gaskets...If you ran current gaskets you will be about 9.3/1 approx..
If you run the Mahle 906 pistons with the 67S heads you will be around 9.7/1 provided that the heads are not decked and it didn't have too many valve jobs. That is without head gaskets...If you ran current gaskets you will be about 9.3/1 approx..
Aaron Burnham
Burnham Performance
1071 Avenida Acaso ste D.
Camarillo, Ca. 93012
805-240-6931
_________________________
Great info. Much lower (and safer?) than what I would have expected.
Thanks
Btw what would be the data using 67S pistons and since we are at it same question w stock 130hp pistons and heads? I understand there is dome difference, valve pocket and valve size that differs.
Richard
searching for engine (case) 903742
What head do you want it calculated from Richard?...NVM, glossed over the 130hp heads..
1967 S piston with a small valve head and No head gasket you are at 9.2/1
with a gasket you are at 8.9/1 approx.
This is assuming the dome volume is correct for the 67S piston.
In the end, If you want to go to 2.2, then I would advise switching to 2.2 heads. It's a better head in every way.
Last edited by BURN-BROS; 09-11-2020 at 12:24 PM.
Aaron Burnham
Burnham Performance
1071 Avenida Acaso ste D.
Camarillo, Ca. 93012
805-240-6931
_________________________
Aaron has not worked with the newest generation of Mahle P's and C's . C. R. will be in the 10's .
For awhile and maybe now when you ordered a Mahle '67 S piston and cylinder set you received a 906 set , and the 906's are not 9.8 : 1 , so it really doesn't matter what the specs are . And the air deflectors don't really fit around the bigger 906 cooling fins ; well they do with modification .
The advertised compression ratios are nominal, the measured numbers are different.
Aaron Burnham
Burnham Performance
1071 Avenida Acaso ste D.
Camarillo, Ca. 93012
805-240-6931
_________________________