[72 Challenger (Hans)]

Hey guys, have a question one of you might know... at least I hope you do. As you know I'm dropping in a hemi this winter. But with a hemi in an e-body you can't remove the valve cover when you have power assisted brakes with a regular brake booster. So I'm thinking of dropping the power part and go to manual brakes.

I could use the stock master cylinder and use another rod for the right pedal height. But is there something out on the market which would give me a better pedal feel? Something less hard... I drove my buddy's cuda a couple of times which has done the same conversion using his stock master cylinder and I think it stinks braking like that.

Also thought of getting a brake booster from a hemi car, but I can't find a business who reproduce these... By the way I don't think my cam will give me enough vacuum anyway with 283@050 duration...

Any input here?

[dave-r]

I think the aftermarket disc brake conversion kits use quite a small booster?

But anyway. I use a more modern MP alloy and plastic master cylinder with NO power assist. It is lighter than the old iron thing. They come in different bore sizes. I think I am right in thinking that a smaller bore size is easier to press but travels further down? So go for a small bore.

I posted something on this a long time ago..

...here it is http://challenger.mpoli.fi/phpbb/viewto ... =5404#5404

[Christer]

I think the aftermarket disc brake conversion kits use quite a small booster?

Take a look at www.ssbrakes.com for instance. I think their boosters are 7" and 9" in diameter. (By the way: The kits that they sell use drum brake knuckles!!!!! Didn´t know that until yesterday, actually. I thought my drum brake knuckles were worthless.)

I think I am right in thinking that a smaller bore size is easier to press but travels further down?

....but the big differance is that drum brakes and disc brakes use different bore sizes. I think that drum brakes use a larger bore.

[Christer]

But with a hemi in an e-body you can't remove the valve cover when you have power assisted brakes with a regular brake booster.

...but is it possible to do that if your car has a "hemi-booster"? (the booster that hemi-cars originally were equipped with.)

[72 Challenger (Hans)]

How's your opinion on how your car brakes Dave without the assist?

I'd rather have non-assisted brakes as besides I don't have enough vacuum anyway I'd also like the extra room I'll gain without the booster.

I just checked out master cylinders from mancini but these are suitable for cars up to 2800lbs and we all know how heavy our cars are!

By the way I have discs in front now...

Anybody out here know a source to get a hemi booster. I know I can get away with one of these.

Thx so far!!

[dave-r]

At first I thought the brakes were poor. But I have a feeling it was the pads because they are a race type and seem to work better when warmed up a lot.

But now I have a few thousand miles on them they don't seem too bad. In fact my passengers all seem to think they work very well.
Sure you need to press hard so if you are used to power assist it feels like nothing is happening.
But now i am used to it I find them fine. I have even had to brake hard on a bend from 90mph and it was no problem.

[72 Challenger (Hans)]

Well, let's just say I didn't built mine to corner very well...

You have that 2800lbs version Dave?

[dave-r]

No idea Hans. No idea why they have put a weight limit on that part anyway. The pressure from your foot and the diameter of the piston is what counts along with the surface area and diameter of the brake surfaces.

If you look in the big MP dealer parts catalogue you will see there are quite a few of these listed. I don't know what all the differences are but all mopars used them from the late 70s on. Like I said. If you are worried about being able to push hard enough with your foot pick one with a piston one inch in diameter MAX.

You will also need an adjustable proportioning valve to prevent rear wheel lock-up.