I have a 1966 Delta 88 that I will be doing a front brake conversion on this year.

Anyone with a 1965-1970 full size Oldsmobile knows the story: front disc brake B body cars made from 1967 to 1970 were rare, and, forty years later, those rare front rotors are a replacement part that is no longer being produced.

So far I have purchased a set of 1969 Delta 88 spindles from a disc brake equipped car and have purchased all the other brake components needed to do the conversion EXCEPT the rotors.

I found a set of late '60s Chevy B body rotors; the plan is to take them to a machine shop to have them permanently mated to the hubs from my '66, making a rotor that will be a satisfactory and effective substitute.

I have been looking on the internet for the specifications for the original rotors. To date I have come up empty handed.

If anyone has a set of original or replacement rotors on a late '60s full size Oldsmobile: would you make available some photos of the rotors (installed or not, or both), or the measurements? And if there is anyone that may have the published specifications for this brake component, would you consider sharing such information?

While I think I'm heading in the right direction, any information would be greatly appreciated.

Thank you
Dave

Hi dwesty,

Welcome to TOC.

I used rotors from an '84 "C" body on my '50 "A" body.

Made the the caliper brackets to fit the spindle and position the calipers. Then machined the rotors to fit the original hubs, and line up with the calipers.

You could install a bracket/disc combo along with a hub, and do the measurements for yourself.

Have fun.

Norm

Thanks for the post, Norm.

Getting all the parts needed for the conversion at a reasonable cost included buying a conversion kit that came with brackets that bolt on to the original drum spindles. I don't plan to use the brackets that came with the kit; I have concerns about their long term suitability under heavy braking.

A vehicle moving at highway speeds has a lot of kinetic energy that has to be converted into heat in order to slow it down, and its even more intense under severe braking conditions. I'm not sure how the disc brakes would fare over the long term on a full size, heavier car that requires even more braking effort in order to slow down or stop it.

Last year I picked up a set of spindles from a disc brake equipped 1969 Delta 88. Those spindles are almost identical to the drum spindles in my '66, except for the backing plate mounts and the caliper guides. Those guides on the disc spindles are sizable and hold the caliper in position to prevent the calipers from moving forward when the brakes are operated. They also minimized the amount of stress against the caliper bolts.

With the bracket kit I bought there are no guide areas to hold the caliper, so the forces against the caliper under braking conditions is transferred through the two bolts holding the caliper to the bracket. Those bolts aren't designed to be the sole means to take all that stress (they are designed to allow for inward & outward motion of the caliper), so how long will it be before those bolts start to bend under constant pressure from the caliper trying to move forward? I don't know, and would rather not go in that direction if it may mean potential brake failure.

Not to say that those brackets should be avoided, but I think that the best solution is to replicate the original engineered setup as close as possible, which is why I want to either find a set of usable rotors or get all the specs so that I can have a set made.