M Calipers and Vented Discs on rear of a SWB

[SteveF_911]

I was wanting to replace the solid rear discs on the rear of my 66 SWB 911, with vented discs and M callipers.

I have a set of M callipers and discs off a SC but the mounting bracket on the swing arms do not fit the M callipers.

Is there an adapter plate available?

Has anyone done this upgrade?

[Grady Clay]

The issue with the SWB rear brakes is both the caliper bolt spacing and the axial position of the caliper. In ’67 Porsche put the vented rotor onto the S. They took the original caliper and added a spacer between the two halves. They also added a half-thickness spacer between the caliper and the trailing arm. (Incidentally these parts will fit 356C axle tubes.)

Another issue you will need to address is the LWB parking brake is smaller than the SWB parking brake so that entire assembly must be changed. Quite an operation.

Best,
Grady

[SteveF_911]

Thanks Grady.

Look like I might stay with the solids. I have never had braking issues I just wanted it to look a bit tuffer and scare the oposition.

[dsfnctn]

I have a 66SWB and was wondering the same thing then I finally just took all the stuff to my machine shop friend and he made an adapter. I had a 82SC parts car and now the complete front suspension and rear brakes on my 66. It is a night and day difference.I used the newer parking brake shoes on the old hubs .

[mjmoran]

dsfnctn,

I am interested in what your machine shop did on your 66. Please elaborate!

Grady,
Have you seen some do the parking brake changeover to the smaller type? What is involved? This would be a great upgrade as the rear hats would be much easier and cheaper to get for theSWB. This along with the vented M rears would be great. Not really much reason to change out the front the the later suspention with S calipers if your stuck with skinny Ls in the rear...talk about break bias issues! Im sure Biil V could elaborate further, but sounds like a disaster to me. I remember a long time ago I had a guy named Dave Troutman make a set of front and rear SWB brakets to mount the later brake stuff. Also, is there a post somewhere on how the put the 944 rear rotor on the SWB? I saw it somewhere a while back.

Cheers,

[Grady Clay]

Michael,

You do some searching on all the forums. The 944 rotor or others might work. When the front rotor was made thicker, did the rear rotor change? I’ll go over to some of the shops and test fit later parking brake shoes. This has been a sore point for many years and deserves some work. Ideally some readily available later parts can be used and only a caliper adapter manufactured.

I have ‘73RSR front suspension on my SWB and it is night and day better. It still has the original ‘68S rear vented brakes which work great with the aluminum S calipers in front. It moved the brake bias slightly to the front with great benefit.

Best,
Grady

[mjmoran]

Thanks Grady. I, right now for an interim have mounted SC M rears on the front and keeping the rear non vented Ls. My L, for some reason, did not have the vented disks as my 67S does. Will see how this holds up. In the mean time I will look for some 944 hubs to try out. Look forward to hearing what you find out in your research.

Cheers,