Disc brake adaptation

[enjenjo]

I am working on a 36 Plymouth right now, and he wanted disc brakes with a 4 1/2" bolt pattern. He had a pair of adapters that he had made to fit Mopar rotors and calipers, but the rotor hit the bracket without the inner bearing seated, it was too deep from the face to the back of the rotor. I tried a Ford rotor, which was better, but there still was not enough room without moving the rotor out further than I was comfortable with, too much load on the outer bearing.

So what I came up with, was using the original hub, with a removable rotor. The rotor I came up with is from a 2000 to 2004 GM full size car, Bonneville, Lesabre, ect. It's an 11" rotor, with about 2" offset, and the bolt pattern was close to being correct. It is a metric bolt pattern, so it was off by .040".

To make the rotor fit the hub, I had to turn .100" from the outer diameter of the hub, and .020" from the pilot of the hub. The rotor then fit like a glove.

The original hub used lug bolts, rather than studs and nuts, which the owner wanted changed, so I used 1/2" by 2" Allen bolts for studs, loctited into place. I had to touch up the inside of the lug holes in the rotor to clear the studs.

For calipers, I used GM pickup calipers, 76 to 80, they are the right width for the thickness of the rotor. For a bracket, I used the bracket the owner had made, and modified weld on rear caliper brackets from UB Machine, at $9 each, cheaper than making them myself.

This whole mess will clear a stock Mopar steel wheel, and should make for outstanding brakes.

I'll add pictures as I get further along.

This moves the wheels out 1/4" per side from stock.

[Charlie Chops 1940]

Good thinking there boss.

Charlie

[t-vicky]

Next time look at Dodge Intrepid rotors. They are Mopar pattern. I used them on my Ford econoline PU.

[rooster]

You da man!

Nice setup.

[jaybee]

Outstanding!  Some of the Pro Touring guys have taken to using late, hubless disks on drum brake hubs or hub-style disks with the disk cut off in order to get big brakes.  They seem to be pretty happy with them and most of those guys use their brakes hard.

[enjenjo]

Next time look at Dodge Intrepid rotors. They are Mopar pattern. I used them on my Ford econoline PU.

I took a look at them today, they have a slightly too large ID to work this time, but I'll keep it in mind.

[enjenjo]

Well, I finally got back to the brakes. For a couple reasons, I didn't use the brackets from UB machine. The biggest reason, I would have to cut so much away, that it was easier to start from scratch. so I made new brackets.

After the brackets were made, and bolted to the calipers, I located them on the spindle brackets, and welded them in place.

That is the last part needed for the disc brake adaptation. Now it's just a matter of bolting it together.

This basic method will work on most applications where there isn't a kit.