Single or dual master cylinder for 1966, question

[Scott A]

Is it pretty common for a 1966 car to be converted to a dual master cylinder?

It seems, the conversion, to be pretty common for the serious 356 people.

[JT912]

There are plenty of 912s that have done this (as I'm sure 911). There was a recent thread over on the 912bbs that had links to the kits and parts needed for the conversion.

[edmayo]

I've done it on my 67 S. You'll need the push rod from the dual master pedal set, and I used a BMW dual chamber reservoir that can mount in the same place as the original reservoir. You'll also need the front brake lines and a banjo to mount the brake pressure switch.

[jim amato]

The blue 901 that was restored by ruf had two single reservoirs mounted in the smugglers box, so I copied that when i converted mine

[mathieulecomte]

It is pretty a common thing to do and for security purpose have the redundancy of the two circuits. It's pretty easy to do and parts are easy to come up, like Ed Mayo, I purchased an ATE BMW 2002 reservoir that fits in place of the original cylindrical version rather than the 68+ square that is located in the trunk.
What you need it you want to do it right is to get a 68+ pedal cluster that has the different rod/plunger and the electrical switch + the slightly different pedal cluster base (with the switch bracket). Then it's a few lines that you can either buy or make and of course the dual MC from ATE.

[Nickelplated5s]

Check out the Alfa Brembo thread. I went to a 22.5mm from ER.

[Chris Pomares]

It just makes sense for safety reasons. Just do it. You only want to upgrade the master cylinder bigger than 19mm if you go to bigger brakes. Stock brakes? Stay with 19mm.

[John912]

As I remember, you can cut/file down the plunger as long as you get the 1 mm clearance. Is my memory still good?

[66S]

I wonder if Porsche had a nickname for dual circuit brakes like they called seat belts “Chicken belts”. I’m sticking with single circuit on my 66. I remember a short story by Joyce Carol Oates about Vinny and his hot rod that ran on $5 junkyard tires, the kind that regularly blow out causing teenage carnage. “I can take care of myself” Vinny said. I don’t know why people install a dual 911 MC in a 356, a Beetle dual MC fits better and costs less. You don’t need two reservoirs, just put a T fitting on the hose.

[jim amato]

I wonder if Porsche had a nickname for dual circuit brakes like they called seat belts “Chicken belts”. I’m sticking with single circuit on my 66. I remember a short story by Joyce Carol Oates about Vinny and his hot rod that ran on $5 junkyard tires, the kind that regularly blow out causing teenage carnage. “I can take care of myself” Vinny said. I don’t know why people install a dual 911 MC in a 356, a Beetle dual MC fits better and costs less. You don’t need two reservoirs, just put a T fitting on the hose.

I also stuck with the single cylinder on my unrestored 67,Actually for what ever reason the single circuit has a better pedal feel than the duel circuit