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COVIN944 FRONT/REAR BRAKE CONVERSION
ARTICLE SUBMITTED BY KEITH WOOLFENDEN.
Disc brake conversions for the COVIN fall into two categories – dead easy at the
back and very difficult at the front!!! Different people have done the conversion in different ways. I can only speak from my own experience. FIRSTLY, THE EASY STAGE OF THE CONVERSATION, NAMELY THE REAR BRAKES, FROM DRUM TO DISC. Porsche 944, up to 1985, are the parts to go for. The rear hubs, back plates, brakes and calipers are a straight swap for the Type 3 setup.
Make sure that you get EVERYTHING
from the breakers, as any parts for a Porsche are horrendously expensive. You will also need the wheel spacers to maintain the Covin track dimensions (£65 each from Porsche!!!)
The calipers are easy and cheap to rebuild – kits from Porsche are often cheaper
than from factors (about £10 per side).
You will need to modify the Type 3 handbrake cables, but this isn’t too much of a problem. I used the Type 3 outer sleeve, shortened, with specially made stainless inner cables with the correct Porsche type clevis at the rear and threaded adjustment at the handbrake lever end. These were made to my spec by Hywel Absalom at Spot on Control Cables Ltd. (01189 790682) The sleeve that fits into the back plate also needs modifying by cutting the middle section out and welding the two ends back together again. Another point to remember is to use the Porsche rubber (0) ring between the brake back plate and the bearing housing, the Type 3 one is too thick and wont let the two machined faces mate correctly. IMAGE SHOWING THE BRAKE SLEEVE MODIFICATION AND THE
THE ESSENTIAL (O) RING. SHOWN BELOW
FRONT END 944 BRAKE MODIFICATION, MORE TRICKY BUT NOT INSURMOUNTABLE, WITH
THE HELP OF A GOOD MACHINE SHOP
At
the front things get more complicated and entail machining of the Porsche hub
and the Type 3 stub axle.
IMAGES BELOW SHOWS THE CALLIPER MOUNTING STANDARD AND MODIFIED
The parts needed are the hubs, discs and calipers from a Porsche 944 post 1985.
You will also need the rear wheel spacers and long stubs to maintain the correct
track dimensions for the COVIN.
The Porsche hub is machined at the rear and fitted with a sleeve to take the
Type 3 inner bearing and the Type 3 stub axle is fitted with a sleeve at it’s
outer end to accept the Porsche outer bearing.
The Mounting “ears” for the Type 3 calipers are cut away and new holes drilled
and tapped to take the 944 calipers.
Splash shields for the front discs will need to be made from aluminum sheet as
neither the Porsche or the Type 3 ones will fit. I made mine by using a
combination of old discs and wooden templates to beat the aluminum sheet to
shape. I have the template should you venture
this far. At the rear the Porsche shield can be used.
The 944 calipers are single piston, but I am told that you can use the two pot
911 calipers or even 4 pot ones with this set-up. This will need checking with
someone like Simon Butterworth at Porscheapart. I thing that the single piston set-up should be perfectly adequate for most application – after all, it stops a 944!!! Although this set-up is mounted on my COVIN, and seems OK I must stress that the braking system has not yet been tested with the car on the road. Therefore, before going ahead with this conversation, consult with your local engineering specialist and ascertain his view on the conversation. I will of course notify you all how successful the conversation is when it is tried and tested. Regards and best wishes Keith Woolfenden BACK
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