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Drum to Disk conversion?

Posted: Mon Dec 14, 2015 2:13 am
by DanWalkowski
I'm trying to assess what it takes to change my 1963 356B drum brakes to disks and hubs like a C. I'm heading down a path of brake and suspension upgrades for the car. My brakes need a rebuild, so I thought I could box up the drums and upgrade to disks. However it's not clear to me exactly what this entails on a 356. Has anyone been down this path? Any advice appreciated...

Re: Drum to Disk conversion?

Posted: Wed Dec 16, 2015 7:43 pm
by Conrad Carter
The list is long! I am in the process of acquiring the parts. Includes: Front spindles, front/rear calipers/rotors pads, brake lines and hoses, mounting plates, rear bump stop brackets, e-brake cables, bearing flanges, bolts, nuts, washers, etc. Best to log onto Porsche website and print out parts list for a C. Look for Illustration 501-00 (Rear Axle), 401-00 (Front Axle), 602-10 (Brake), 604-05 (Master Cylinder), and 604-10 (Brake Lines). I can send you a detailed list but won't be where my computer is until 28th. Hope this helps. Conrad

Re: Drum to Disk conversion?

Posted: Thu Dec 17, 2015 5:42 am
by Mike Ruddy
Some reading here...

viewtopic.php?f=1&t=26675&

Re: Drum to Disk conversion?

Posted: Thu Dec 17, 2015 7:08 pm
by DanWalkowski
Conrad, I was wondering if you had to order C parts to accomplish this. I would welcome the list you offer.
Mike, I've read through the thread you reference, and have talked to Airkewled.
I'll continue to evaluate....
Thanks to both of you!

Re: Drum to Disk conversion?

Posted: Thu Dec 17, 2015 10:21 pm
by Glen Hamner, Jr
Will the faithful in the know wade in here? I have considered the benefit of moving to a disc brake setup, but have been left wanting. My memory of reading the details is that the move to disc by Porsche was to keep up with the Joneses. I have come away form the discussion, right or wrong, with the belief that the Porsche drum brake assembly is both lighter in unsprung weight than the disc, and equal or better in stopping power, provided all the elements of the systems where in good working order and proper fitment. If my memory is correct, there is nothing to be gained by moving from Porsche 356 drums to any disc assembly system in the marketplace? All told, the advantage in handling and stopping power with properly maintained drums is superior to anything with disc, per my reading of the tea leaves.

I remember when there when the myth began that disc brakes did not fade in the wet like drum brakes. Wellllllll, my experience is that if they are both run through high water, neither system works very well until properly dried out, and both pads and shoes take about the same length of time to come back to full functionality. Soooooo, why are folks spending their limited/excessive hard earned resources to move to a braking system that is in all respects inferior to what Porsche originally installed on our beloved B model tubs? Is it just so they can mount a set of Fuch wheels, or some other disc compatible wheel that only fits on the disc brake lug pattern?

Those in the know, please clear the air on this one.

Re: Drum to Disk conversion?

Posted: Thu Dec 17, 2015 10:32 pm
by Martin Benade
From what I have heard for racing the disks are clearly an improvement, but for most road use the drums do quite well, as long as you don't need to slow down from 80 mph five times in a row, at which point they are getting pretty hot and fading.

Re: Drum to Disk conversion?

Posted: Fri Dec 18, 2015 6:30 pm
by Geordie Greenwood
I converted my A coupe to "C" disc brakes when I started to vintage race the car in the late 80's. There is no doubt that disc brakes offer much better resistance to fade than regular drums, and are much less expensive to maintain than drums with this type of usage. I did race a car with 60mm drums at Laguna Seca many years ago, and would say they are equal to discs, but at a substantially higher cost.

If you intend to drive your car fast and hard on twisty roads, you can't go wrong with converting to disc brakes, and if you use "C" brakes, you are simply updating with the correct Porsche parts.

Geordie

Re: Drum to Disk conversion?

Posted: Fri Dec 18, 2015 11:01 pm
by C Richey
Geordie:

E-mail please. There is no e-mail within your profile.

Thank you,
CRichey

Re: Drum to Disk conversion?

Posted: Sat Dec 19, 2015 1:21 am
by Greg Bryan
To check your 356 Registry E-mail and to confirm that the 'email' button is visible to other members, go to this thread and scroll down to find the appropriate post

Frequently Asked Questions
viewtopic.php?f=1&t=38165

Re: Drum to Disk conversion?

Posted: Sat Dec 19, 2015 2:40 am
by DanWalkowski
Glenn H, you raise valid points.

I was researching this as an alternative to consider vs the work and cost I was about to face to correct a progressively softening pedal feel. I use the car for touring and spirited driving at best. I'm going through the steering, suspension, and drive train to renew where it's needed.

At this point, I'm replacing rear cylinders, along with new shoes and springs and drum resurfacing all around. This will dramatically improve stopping.

Another project is to correct about 1-2 inches of free play by rebuilding the accelerator linkage from pedal to carbs, which will improve the "go" side , but that's for a different thread...

Re: Drum to Disk conversion?

Posted: Wed Dec 23, 2015 10:42 am
by Doug McDonnell
Registry Magazine volume 24-6 page 16 has a Technical article written By Vic Skirmants that should help.

Re: Drum to Disk conversion?

Posted: Wed Dec 23, 2015 1:57 pm
by Glen Hamner, Jr
Excellent reference Doug to all the reasons I never considered the need to move from drums to disc. Vic make it perfectly clear that there was a modification trail to follow that in many ways reminds me of the paths some have taken to install an early 911 rear suspension into a 356 chassis. Why do folks do these things, well, because they can.

Interestingly, in the same publication are some of the answers as to what happened to bits of the vehicle James Dean was driving when he met his Maker. All this history right within our Registry's digital fingertips.

Yes, its took my MAC a while to download all the files from the above mentioned magazine article, but, its well worth rambling through these past publications to become more fully immersed in the 356 lore.

Re: Drum to Disk conversion?

Posted: Fri Jan 13, 2017 6:45 pm
by Hugo Karasawa
I know this post started a couple of years ago.
I would like to know if any of the interested people did the drum to disc conversion ?
And if you did the conversion could you please let us know what you did and what problems did you encounter.

Re: Drum to Disk conversion?

Posted: Sun Jan 15, 2017 10:39 am
by Bill Sargent
For probably about the same (in today's market) it would cost to purchase a complete C disk brake set up to convert a drum brake car you may want to consider an alternate route. Purchase a set of GT front drums, have your front and rear backing plates converted to GT with the scoops and it will stop just as good as disc brakes. I have a 64 C cab with discs and a 59A cab with the GT brake set up. It is a toss up as to which stops better.

Re: Drum to Disk conversion?

Posted: Sun Jan 15, 2017 3:49 pm
by Paul Lima
I have the 60 mm GT brakes on my Roadster, and for street use, they are more that you could ever need. When I Vintage raced this car, it wasn't difficult to over drive the brakes; disks would have been much better (but not legal) so you learn to drive as fast as the brakes are up to the task.