Finished the scarebird conversion, a few notes.

gsxrken said:
All wheel drum cars don't have prop valves b/c the wheel cylinders are sized differently Front and Rear, which serves the same purpose.

What I am interested in hearing more about is that both these guys seem to have had braking issues with the shuttle valve out of position... I have been led to believe that that shuttle is strictly for the light. Are you two saying it did interfere with brake fluid flow too, and that centering it (or getting a new one) imporved your braking?

Yes it did affect the braking, markedly as described in the two previous posts. I couldn't get it to recenter, so I replaced it with an adjustable Proportion valve.
 
  • Sponsors (?)


Scarebird Bolts

What bolts did you use to attach the scarebird brackets to the spindles?

I am doing the scarebird conversion with a upgraded dual MC.
Any additional information on how to run the lines of the MC and where to attach the PCV would be appreciated.
Thanks
 
Just to update this thread...with my results of my Scarebird conversion and the ensuing hunt for a MC that gave decent pedal travel, and pedal pressure required to stop the car.

After putting the 74 Maverick MC on my car and being grandly dissappointed...way, way too much pedal travel...I went back and did some research on the calipers used in the Scarebird kit. They are from an s10 truck, and are what is known is a "quick fill", or "rapid take up" design.

Basically, back in the 80's GM designed a caliper with specially designed seals that pull the piston further back into the caliper than a "normal" caliper. This reduces drag, and gave slightly better gas mileage.

However, it requires a specially designed master cylinder that essentially has two pistons, one larger, one smaller. When you first push on the brake pedal, the larger one first moves - pushing a large volume of brake fluid to the caliper to push the piston/pads into contact with the disc - then the smaller piston takes over and provides the pressure to really stop the car.

So, you MUST use the right MC or you will never, ever get the feel of the brakes right. I have yet to find a quick take up MC for manually brake cars. Too bad Scarebird doesn't tell you this up front.

The good news is that with a little modfication, you can make the stock s10 master cylinder work, but you will have to live with the extra pedal effort since you are using a power brake MC on a manual system.

Just trying to give everyone the heads up.

Good luck...
 
...I went back and did some research on the calipers used in the Scarebird kit. They are from an s10 truck, and are what is known is a "quick fill", or "rapid take up" design.

Basically, back in the 80's GM designed a caliper with specially designed seals that pull the piston further back into the caliper than a "normal" caliper. This reduces drag, and gave slightly better gas mileage.

However, it requires a specially designed master cylinder that essentially has two pistons, one larger, one smaller. When you first push on the brake pedal, the larger one first moves - pushing a large volume of brake fluid to the caliper to push the piston/pads into contact with the disc - then the smaller piston takes over and provides the pressure to really stop the car.

So, you MUST use the right MC or you will never, ever get the feel of the brakes right. I have yet to find a quick take up MC for manually brake cars. Too bad Scarebird doesn't tell you this up front.

I do not believe that is the issue. We have used many post 1979 GM calipers with no ill effect. The amount of piston retraction is minimal: this is accomplished by the seal having been "coined" - formed with a radial twist. We have been told the amount of retraction at the caliper is about 0.020", which translates to about 0.065" master piston travel - this is a negligible amount at the pedal.
 
so which is it? the maverick master or another unit? btw, I want a ten dollar refund not knowing that i could of gotten ten bucks off when i ordered my set for my 65 a couple of weeks ago.:shrug: