Carrera USA/EURO

[DIANA]

What is different?
I know that compression USA is 9.5:1 and Euro is 10.3:1
Where is difference?
-crankshaft
-rods
-cylinder
-piston
-head

Thanks

[Bill Verburg]

If you ar asking about '84-89 3.2 Carrera, the diffference is in the pistons/cylinders, exhaust and DME parameters.

All the Euro 930/20 or /26 w/ 10.3cr used forged Mahle pistons w/ Nickasil cylinders, the 9.5cr 930/21 or /25 used either forged Mahle or cast Kobelschmit Alusil

the 930/20 has a pre-muffler the others a cat

[DIANA]

Well ,but why the reference cylinders in PET is the same for 930/20/21/26?

Thanks

[Bill Verburg]

Originally Posted by DIANA

Well ,but why the reference cylinders in PET is the same for 930/20/21/26?

Thanks

They may be physically interchangeable as sets but the fact of the matter remains, at original assembly the 231hp 903/20s all got forged Mahle 10.3 w/ Nikasil cylinders, all the others got either 9.5 forged Mahle/Nikasil or cast KS/Alusil. Which you got was hit or miss w/ the purported preponderance of KS going to US cars

[DIANA]

Originally Posted by Bill Verburg

They may be physically interchangeable as sets but the fact of the matter remains, at original assembly the 231hp 903/20s all got forged Mahle 10.3 w/ Nikasil cylinders, all the others got either 9.5 forged Mahle/Nikasil or cast KS/Alusil. Which you got was hit or miss w/ the purported preponderance of KS going to US cars

But the difference of material doesn´t mean that the CR is different.
There must be any difference in height piston or cylinder,and reference is de same in PET

[Bill Verburg]

Originally Posted by DIANA

But the difference of material doesn´t mean that the CR is different.
There must be any difference in height piston or cylinder,and reference is de same in PET

That's correct, but the 10.3 pistons are all forged Mahle and are used w/ Nickasil cylinders

and

the 9.5 pistons can be either forged Mahle(w/ A lower piston top to give less compression) or KS cast. The former will have Nikasil cylinders and the latter will have Alusil.

I don't understand what is so confusing about that.

for the Mahles there were 4 different weight classes for 930/20/25/26 and 4 more for 930/21


for the KS there were 4 more different weight classes only used on 930/21

on the production line the spec is to have all pistons w/i 4 g, for service afterthe fact the spec is to be w/i 8g

[Bobboloo]

Originally Posted by DIANA

What is different?
I know that compression USA is 9.5:1 and Euro is 10.3:1
Where is difference?
-crankshaft
-rods
-cylinder
-piston
-head

Thanks

The pistons are what made the compression difference. They had a higher dome. The crank, rods, cylinders and heads all had the same dimensions for both Euro and USA.

If you wish to change the compression just make sure that you match Mahle pistons to Mahle cylinders or KS to KS. They can't be interchanged between the two brands.