Has any body installed the Scarebird conversion on their cutlass? It uses 11 1/2" jag rotors and chevy truck calipers. I was wondering if 15" SS111 wheels work with it.

 

I can't speak for the Scarebird products, but I used Inline Tube's disc conversion kit. I had to go with 15" wheels, which worked fine.

 

I guess I don't even understand why there's a market for this. The stock rotors are 10.75" with calipers that use 2.75" pistons. The factory disc brakes CAME with 14" wheels, so fitment is a non-issue. GM single piston disc brake parts pretty much grow on trees, so availability is extremely good. More importantly, the Scarebird caliper mounting brackets do not support the sides of the caliper the way the factory brackets do. All braking loads are carried through the caliper mounting pins, which are not designed for that load.

 

I'll also add that if you want larger brakes, here's a cheaper way to get 12" rotors on an A-body. No, these will not clear SSII/III wheels.

http://www.pozziracing.com/cheap_big_brakes.htm

 

Because most of us aren't as knowledgeable as you are, and the vendors tell us that we have to use 15" wheels. In my case, I really didn't mind since I'm not showing my car in judging and I liked the idea of going to 15" wheels. It's easier to buy the complete kit from a vendor as opposed to rounding up the individual pieces, especially when you don't have the knowledge you should have. Plus, there seems to be this perpetual myth that 14" wheels will not clear disc brakes. All that plays into the hands of the vendors who are happy to help.

 

With the exception of the 1969 H/O, every single 1967-1972 Olds A-body that came from the factory with disc brakes also came with 14" wheels. I've asked several vendors of disc brake kits why they specify 15" wheels. The answer was always that it was too much trouble to educate the buyers about the differences in 14" wheels.

This photo has been posted a bunch of times. The wheel on the left is a GM 14" disc brake wheel. The wheel on the right is a 14" drum-only wheel. The inboard side of each is to the right in the photo. Note the difference in the shaping of the center drop part of the rim (green and yellow arrows). The disc wheel is shaped to clear the caliper. The bead on the backside of the disc brake wheel (lt blue arrow) is visible even with the tire mounted. Every single SSII/III wheel ever made by Olds clears the factory disc brakes.

 

Joe ,the ponzzieracing link for cheap big brakes ,is almost the exact same thing as the scarebird system. The jag rotors scarebird uses are 11.5 x 1.1 calipers used are chevy truck with 2.94 pistons I can get pro stop calipers from autozone for $1.29 out of pocket shipped to the house. Using coupons and credit card points Pro stop drilled and slotted rotors, from rock auto for $ 80.24 shipped . The brackets are $95. Ponzie racing has been racing cars for years , with flat caliper brackets. Dont think I need to worry about about the caliper pins. I havent ordered because I dont know if SS111 wheels fit

 

Their web page shows mods to the OEM brackets for the 12" rotors, not a flat plate bracket. In any case, think this through. Why would GM, who pinches every penny possible in the cost of building a new car, waste money on forming far more complex brackets that fully support the caliper if they didn't need to? Do you think they are trying increase the cost of building cars? Maybe they don't want to make too much profit?

The caliper pins are 1) not intended to take bending loads, and 2) are mounted in rubber o-rings. Neither of these is what you want for the primary load path for a brake caliper. Yeah, I'm sure it's fine for a car that only gets driven to cruise night and back. As an engineer, I certainly won't use that design on my cars.

 

Not everyone can be an engineer, and when an engineer speaks, instead of listening and learning, a lot of people bull up and feel affronted.

The reason the scarebird system is junk is because it uses the drum spindle with some weird brackets that don't account for the loads well.

 

Why even bother with Scarebird stuff when there are plenty of other options for 15" wheels??

 

You could use a shorter upper control arm and a spindle from a 70-81 F Body, 73-77 A Body, or 77-96 B Body. You do however, lose some turning radius due to the longer tie rod mounting location. I just happen to have upper and lower control arms....and the spindles....all you need are rotors from the 89-91 F-body to retain your bolt pattern and you get a 12" rotor!!!

 

The problem with the later tall spindles, even with the correct upper control arms, is the bump steer due to the incorrect steering arm shape for the 64-72 A-body chassis. Yeah, the stock suspension still has bump steer, but the later spindles make it worse.

 

Joe is right . the Scarebird conversion is scary. Not going to use it. I had their conversion method mixed up. with two of the methods on pozzieracing.com . The one I think I will use does use flat plates . It is 12" brakes by By Rich Downing. This on looks safe What say the engineers?

 

This is apple and kumquats.

The Scar(Y)bird conversion uses thinner flat plates with a sliding caliper supported by pins only. This much thicker plate only mounts a factory support bracket (the black part around the caliper). This is exactly the right way to mount the Corvette calipers, but it doesn't apply to mounting a single piston GM sliding caliper.

 

Thanks Joe. I did mix the information of the three conversions up. I now am going to proceed withe the last one I posted.
Again thanks