disc brake conversion

I have had disk brakes on my roadster for years....with no vacuum assist..and I would not want one...it stops easy and quickly...works fine...there are some tricks though...

The kits most places sell will not work using wire wheels...there is too much setback on our rims to allow for the caliper clearance.... it won't work using our wheels...

The rotor hats I used were Suzuki Samari ....they are 5 on 5 1/2 pattern and have a large setback... the calipers I used were Willwood brand but Volkswagen would also work...

You will want to use a AMC master cylinder as the outlets are on the oposiite side than a Chevrolet dual master....you will be mounting the master cylinder backwards so you want the outlets pointing toward the frame... you will pull the tube seat out of the front part of the master cylinder as you don't want residual pressure in that front line...or you will drag your disks..

By using deep rotor hats you will position the rotor surface in line with your kingpins so it will not cause any kind of pull in a panic stop...plus you will not need to space your wheels out...I think that kinda look mickey mouse when I see a car where they have done that...

I use 40 Ford rear drums so I use a late model Ford proportioning valve that I make adjustable...(easy to do).. but you can buy adjustable valves if you want.
The only thing I would like to do now it to change the backing plates on my drums to make them servo brakes ....as they are now they have 2 anchor positions ....and do not self energize.

Joel
Retired College Shop Teacher
 
Check with ECI (Engineered Brake Components) 860-872-7046. I bought a kit from them to to put Disc Brakes on my 46 Coupe but kept the drum brakes on the rear.
 
Sure it will work on your 46 coupe...but that does not have Model A wires...and the rim on your 46 is almost flat...the A has a huge setback in the rim...

Joel
 
Is there anybody here who has 4 wheel disc brake set up without boost???
What set up did you use and what feedback can you offer???
 
Is there anybody here who has 4 wheel disc brake set up without boost???
What set up did you use and what feedback can you offer???

Yes. I have a complete Wilwood kit on my 30 2door. No power.
Swing pedals, dual cylinders with adjustable bias bar, mechanical parking calipers, carbon fiber pads, et al.
I used the Wilwood aluminum hubs so I could run aluminum wheels. This essentially the same setup I have on my race car.
When I first did the conversion I made up a set of model A wheels to fit but later decided I wanted more rubber on the ground. I don't do parades or shows any more so I don't need the original look.
 
Anyone have an idea where I can locate some rear servo style backing plates ? or better yet, an idea of what servo brakes would work in the rear with a parking brake??


Joel
 
Yes. I have a complete Wilwood kit on my 30 2door. No power.
Swing pedals, dual cylinders with adjustable bias bar, mechanical parking .

Heck, using two M/Cs with the appropriately-sized bores and a bias bar makes it a piece o' cake, 'cuz the required fluid volume (using two M/Cs) isn't compromised by running out of available pedal stroke first, as is usually the case with a single (appropriately-sized bore) M/C in an UN-boosted system.

If a M/C's diameter is small enough, and the available stroke of the piston is long enough to supply the volume of fluid required at the four wheels, AND if the pedal travel is available to facilitate that piston stroke (at an appropriate and comfortable pedal ratio), then NO.....you wouldn't need a booster. Trouble is, in the real world, M/Cs don't have a long-enough stroke (at the proper diameter), and the pedal doesn't have enough available stroke. In most cases, the best COMPROMISE is a booster, with the pedal ratio optimized, and with the M/C diameter sized just a tad too big. DD
 
Heck, using two M/Cs with the appropriately-sized bores and a bias bar makes it a piece o' cake, 'cuz the required fluid volume (using two M/Cs) isn't compromised by running out of available pedal stroke first, as is usually the case with a single (appropriately-sized bore) M/C in an UN-boosted system.

If a M/C's diameter is small enough, and the available stroke of the piston is long enough to supply the volume of fluid required at the four wheels, AND if the pedal travel is available to facilitate that piston stroke (at an appropriate and comfortable pedal ratio), then NO.....you wouldn't need a booster. Trouble is, in the real world, M/Cs don't have a long-enough stroke (at the proper diameter), and the pedal doesn't have enough available stroke. In most cases, the best COMPROMISE is a booster, with the pedal ratio optimized, and with the M/C diameter sized just a tad too big. DD

Yup, all that is true, BUT, I have a single master cylinder
on my race car with the essentially the same kit and I can VERY EASILY lock up all 3 brakes at 110 mph at the end of the straight.
As I see it a power booster is added to compensate for poor engineering. A cheap way out.
 
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