Why 944 Mcyl vs 911?

[evilC]

[QUOTE=Humble;70404]The #'s on the MC are 26 and 20

QUOTE]

I too would have thought that the numbers refer to the bore but the information I have been able to gleen is that the 930 ran plain bore 20mm pistons. It maybe that my numbers relate to a different (earlier?) version of the model in the same way that the 944 m/c changed to a stepped bore from a plain bore. I presume that the #26 is at the pedal end of the bore?

Clive

[Simon]

[QUOTE=evilC;70407]

Originally Posted by Humble

The #'s on the MC are 26 and 20

QUOTE]

I too would have thought that the numbers refer to the bore but the information I have been able to gleen is that the 930 ran plain bore 20mm pistons. It maybe that my numbers relate to a different (earlier?) version of the model in the same way that the 944 m/c changed to a stepped bore from a plain bore. I presume that the #26 is at the pedal end of the bore?

Clive

The 930 Turbo 78-89 is a dual circuit 23,8mm MC (930 355 011 03).
AFAIK it was used with a brake booster as well (1984: 930 355 027 00, >1984: 930 355 027 02)

[Humble]

Originally Posted by evilC

I too would have thought that the numbers refer to the bore but the information I have been able to gleen is that the 930 ran plain bore 20mm pistons. It maybe that my numbers relate to a different (earlier?) version of the model in the same way that the 944 m/c changed to a stepped bore from a plain bore. I presume that the #26 is at the pedal end of the bore?

Clive

Actually 20 is by the pedal and 26 on the end. I thought I read somewhere that the 930 had the same 4 pot calipers all around but the piston sizes were different front to rear, the rear calipers being smaller.

[evilC]

Humble, The #20/26 can't be the piston sizes as the larger one would have to be at the pedal end! If the caliper piston sizes were smaller at the rear then it would have been more likely that the m/c would have the same bore size for front and rear circuit since the bias will have been controlled by the caliper sizing. It would be unusual for the manufacturer to have controlled it by both the caliper and the m/c (late 944 excepted). The 23.8mm (15/16") bore size does imply a power assisted pedal as it is quite large for non-servo assistance, which are generally </=19mm

Clive