Scarebird Disc Brake Conversion

[68droptop]

Has anyone installed the Scarebird Disc Brake addaptor system that is advertised on E-bay? It is a bracket that mounts to the existing drum spindle and uses 1990 Chevy Celebrity disc brake calipers. I know that it is not pure Olds, but I am more interested in stopping safely in modern traffic. The other plus is I will be able to reinstall the drum system if I want. I just want to know if anyone has any experience with the system.

[texasred]

I Googled and this was one of the few boards discussing Scarebird that actually stayed on topic...http://www.hotrodders.com/forum/scar...ets-79303.html

And a Cutlass Ciera is the same thing as a Shi*lebrity, so you CAN keep it all Olds!

C.J.

[68droptop]

Thanks for the link. It seems that folks are pretty happy with the conversion, and yes, Ciera it will be!

[Scarebird]

I designed especially for the Olds SS1 rims. Years ago I had a 1966 442 convertible with these rims; and could not find a disc conversion. So years later made it my goal to build one. They work well, but if you are running a mean-ass W30 type motor, you may want to step up to 15" rims and get bigger rotors!

[Oldsguy]

Hi Mr. Scarebird.

Thanks for your personal input. Nice looking cat....

[joe_padavano]

I've not used the Scarebird parts personally, so I can't comment one way or the other.

I do want to suggest an alternative, which is the currently available repro A-body caliper brackets. These seem to go in the $40 range on ebay. The 64-72 A-body drum and disc spindles are identical except for the upper bolt (there are three bolts holding the backing plate to the spindle, two of which are used to hold the caliper bracket in the factory configuration). You can have your drum spindles drilled and tapped for this larger bolt at any competent machine shop (or do it yourself with the proper tools). Now you can use readily available stock rotors and calipers (still available at all auto parts stores). You'll need a new master cylinder, proportioning valve, hoses, and hose brackets in either case.

[68droptop]

Thanks Joe. Just two questions, do the A-body brakes work with stock 14" rims or did the disc brake cars have 15" wheels? If I understand your reply I only need to re-tap the upper bolt, the other two holes will work, is that correct? Thanks Again

[joe_padavano]

Originally Posted by 68droptop

Thanks Joe. Just two questions, do the A-body brakes work with stock 14" rims or did the disc brake cars have 15" wheels? If I understand your reply I only need to re-tap the upper bolt, the other two holes will work, is that correct? Thanks Again

Yes, the factory 10.75" rotors clear stock 14" rims. Just be aware that many rims built in the 1960s and early 1970s (both factory and aftermarket) do not clear the disc brakes. As an example, all Olds 14" SSII and SSIII rims will clear, but only the painted SSI rims offered in 1971 will clear. The older chrome SSIs from the late 1960s do not. The profile of the outer rim section of the wheel is different. If you look at the wheel with the tire removed, you'll see a drop-down section between the areas where the tire bead seats. On drum-only wheels this drop-down section is centered between the beads. On disc brake wheels the drop-down section is offset towards the outside to clear the caliper. It's very obvious when you have two wheels side-by-side.

[68droptop]

Great! I hate to be a pest, but could you give me a quick answer on the second question about re-drilling the spindles? Thanks

[joe_padavano]

Originally Posted by 68droptop

Great! I hate to be a pest, but could you give me a quick answer on the second question about re-drilling the spindles? Thanks

Sorry, I missed that one.

The factory spindles have three bolts that hold the drum backing plate in place. The two bottom ones are through-holes with a bolt and nut that also hold the steering arm to the spindle. The top bolt threads into a tapped hole in the spindle and (if I recall) holds the bracket that retains the pistons in the brake cylinder.

Unbolt these three fasteners and the drum backing plate comes off the spindle. The two bottom holes are unchanged for the disc configuration, but the top threaded hole needs to be enlarged and tapped for a larger bolt. I don't have the thread specs here at work, unfortunately. When you reassemble the spindle, the disc brake splash shield is held on with all three bolts. The steering arm uses the bottom two, and the caliper bracket uses the top one and one of the bottom two, depending on which side of the car it's on (the spindles are the same, just the bolt-on arms and caliper brackets are RH and LH). The through bolts that hold the steering arms should be long enough to also hold the caliper bracket.

[68droptop]

Thanks a million Joe.