I'm doing a bit of planning in advance of building a rear-engine dragster, (slant-powered, of course), and would like a bit of advice concerning brakes.

I can get a Ford 8.8 rear out of a former squad car, and it's equipped with discs. Knowing that calipers require a larger volume of fluid, and planning to have brakes only at the rear, I find myself slightly stumped as to what to do for a master cylinder.

I suspect an older single-pot won't deliver the needed volume, but a dual-pot will give me the problem of what to do with the fluid from the "rear/small" chamber. (I rather not run one chamber dry.) I wondered what might happen if I used a dual, with straight bores, (not the "stepped" variety), and tee'd both chambers together, sending all the fluid to the calipers on the rear.

Thoughts, suggestions, judgements that I'm insane?

Roger

You can purchase a Wilwood style brake pedal that uses a single outlet mastercylinder sized to your liking. You can pick up a used pedal and master for about $40 or new for about $100.

Im not sure if this is similar but,,,, we only use the front discs on our 4 wheel drive mudbogger. I was faced with a similar dilemma. In the end I used a manual master cylinder from a mid 60s Vetter with 4 wheel discs. I plumbed one chamber to each front caliper. The theory being I had a split system where failure on one circuit would still leave enough brakes to stop the truck. Light, cheap, balanced, split system.

Yeah,,,yer prolly insane.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

I have the singe pot MC on my 66 Dart with the KS 4 piston discs, it stops fine and does not loose much fluid into the calipers over time.
When the factory did this in 65-66 they put an extension on the single pot's reservor!
I don't have the extension, just top-off my brake fluid every year or so.
DD

For DD: How did the factory plumb the brake lines for the discs? Was it still a single distribution block or split F/R system?

It isn't too difficult of a task to build a custom brake system. First thing you'll need to know is the piston size in those 8.8 calipers. Once you know that you can do the system design. You also need to know your pedal ratio and the diameter of the rotors.

Once you know all of the info you can solve the equation for master cylinder bore size. Once you know that, you just go shopping for a single port master cylinder with the correct bore size.

The system uses a single distribution block and is not split F to R.
There is also a separate factory porportioning valve which is added into the rear line, to keep the pressure biased to the discs. The car is still a tad bit rear wheel lock-up pron in the wet, I should go to a aftermarket, adjustable P. valve to help that.

With any single pot master cylinder system, be sure your E-brake works and practice using it to bring the car to a stop, in an "emergency".
Also inspect those front flex lines and replace them at any signs of cracking. One leak anywhere in that single cylinder system and you will not have hydraulic stopping power.
"Brakes....don't need no stinkin brakes.." (I have anti-sway bars and good suspension)
DD

Get an ABS master from an 87-88 thunderbird turbocoupe and use the anti ABS rotors. Its already the right size. Might even bolt right up.

Wilwood, Tilton, and others make single-pot master cylinders with various bore and reservoir sizes for $60-100. Lightweight, easy to mount...

Lou

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