'64 master cylinder conversion

[garth64]

has anyone ever converted their non power brake master cylinder to a dual cylinder? and if so, what's involved? thanks.

 

[rohard]

Zip Corvette offers a Daul Master Cyl conversion kit for your 65.



Go Here..

http://www.zip-products.com/Zip/pro...47629A9B67A7F77


And Go here for brand new O ring Calipers.. thses guys are the best IM

http://www.vbandp.com/

I asked the same question a couple of weeks ago. Above is courtesy of VietnamVet. Look back a page in this section for more info. Ordered the kit from Zip, awaiting delivery.

 

[Ol Blue]

JohnZ mentioned to me that for drum brake cars one could use a dual master cylinder from a drum brake Camaro. From what I understand, the disk brake master cylinders have a residual valve in them that helps keep the brake pads close to the rotor. Maybe ZIP has that problem covered when you tell them you want a dual system for a drum brake car, but you might want to really push them to answer the question.
Ol Blue

 

[stepinwolf]

Easier solution

The Camaro MC are expensive, and tend to be hard to find. Use a dual 67 rebuilt MC that can be had from any " auto-parts " store with a 1 1/8" bore, and ad a 20$ residual valve to the rear line. Works great, and very reliable.

As a zillion builders of Hot-Rods, they all have'um and they work.

 

[Mike McKown]

The question I'd have to ask

is what is that 1 1/8' main cylinder bore going to do to brake predal effort? The Corvette drum brake cylinder is 7/8".

 

[stepinwolf]

Normally you should need less pedal effort for the same results as before.

BTW it's not necessary to specify the size, the only reason I mentioned the 1 1/8" is because it has become the norm for the twin reservoir replacement MC's.

If you don't mention it to your parts store and just inquire about a replacement for a 67 Vette, this is what they will be supplying you with.

Bob

 

[Mike McKown]

I'm confused

Normally, a small main cylinder bore will result in more pressue/ less volume to the brake system with longer stroke. A larger main cylinder bore will result less pressure/more volume to the system with less travel.

Can you explain how the two piston '67 Corvette, 1 1/8" bore cylinder will give LESS pedal effort than a 7/8" stock cylinder?

I've often wondered about '63-'64 drum brake Corvette owners that complain about high pedal effort if someone hasn't replaced their 7/8" main cylinder with a 1" from a pass car. It does result in quite a bit higher pedal effort.

 

[JohnZ]

JohnZ mentioned to me that for drum brake cars one could use a dual master cylinder from a drum brake Camaro. From what I understand, the disk brake master cylinders have a residual valve in them that helps keep the brake pads close to the rotor. Maybe ZIP has that problem covered when you tell them you want a dual system for a drum brake car, but you might want to really push them to answer the question.
Ol Blue

It's the other way around - drum brake master cylinders have 10 psi residual pressure valves in the outlet ports; that constant pressure in the system partially overcomes the retraction springs on the shoes so less fluid displacement (pedal travel) is required to get the shoes in contact with the drums when you step on the brakes. Disc brake master cylinders don't have any valves, as the pads are essentially in constant light contact with the rotors and very little fluid displacement (pedal travel) is required to get the pads in contact with the rotors.

With a front disc/rear drum system, the master cylinder has an RPV in the rear outlet port for the rear drums, and none in the front outlet port for the front discs.

 

[Ol Blue]

My apologies to all, esp. JohnZ. I should have checked my facts instead of trying to go from memory. The Air Force always said go to the manual to check specs instead of going from memory. Those props falling off in mid-flight is NOT recommended. Given that I'm talking about reciprocating engines maybe you can understand how my memory wasn't so good. I'll do better!!!

Ol Blue

 

[JohnZ]

Those big Pratts were fun, weren't they? I always marveled at the 4-row 36-cylinder turbo-compound "corncobs" on the B-36's in Fort Worth; a plug change on one of those "aluminum overcasts" only required 432 spark plugs (!)