[Healeys] Brakes -rear wheel cylinders

[Bluehealey]

A big Yes!
The rears are over braked with the big cylinders. The line pressures are higher with discs and it becomes easy to lock the rears on 1” cylinders. BMC knew what they were doing.

Alan - from my iPad

> On 24 Mar 2019, at 22:19, Bob Haskell <rchaskell at earthlink.net> wrote:
> 
> Listers,
> 
> The rear wheel brake cylinders are 1" diameter on the 100 and 100-6. When the disc brakes were introduced on the 3000 MkI, the  wheel cylinder diameter changed to 3/4".  So if one is fitting a 3000 disc brake set up to an earlier car, should the rear cylinders be swapped out too?
> 
> If I'm doing the math correctly, the force on the brake shoes with the smaller cylinders will be 56% of the force with the large cylinders, for the same hydraulic pressure.
> 
> force = pressure * area
> area = PI * (dia / 2)^2
> 
> 1" cylinder -> area of 0.785 sq. in.
> 3/4" cylinder -> area of 0.442 sq. in.
> 
> 0.442 / 0.785 -> 0.562 or 56%.
> 
> Cheers,
> 
> Bob Haskell
> Austin Healey 3000 MkI registrar
> http://www.ciahc.org/registry_3000mk1.php
> _______________________________________________
> Support Team.Net http://www.team.net/donate.html
> Suggested annual donation  $12.75
> 
> Archive: http://www.team.net/pipermail/healeys http://autox.team.net/archive
> 
> Healeys at autox.team.net
> http://autox.team.net/mailman/listinfo/healeys
> 
> Unsubscribe/Manage: http://autox.team.net/mailman/options/healeys/bluehealey@gmail.com
>