Quote:
Originally Posted by 1948F-1Pickup
The movement increase is about 3/8" at the master when comparing the larger bore master of 1 1/16" and the greater amount of piston movement with the smaller bore master of 1 inch. (0.866" piston travel in the 1 1/16" bore to move 1 cubic inch of brake fluid vs 1.27" piston travel in the 1" bore to move 1 cubic inch of brake fluid)
With that extra 3/8" AND the pedal ratio, you might very well bottom the brake pedal into the floorboard on some vehicles/applications.
It wasn't a problem on my '48 truck but it just underscores that you wouldn't know the true story unless you did the math.
|
Gonna have to disagree with some of the above math.
1" master cylinder piston travels 1.27" for 1 c.i. of fluid movement.
1 1/16" master cylinder piston travels 1.12" for 1 c.i. fluid movement.
The 1" piston travel increase is
.150", or just over 1/8",
not 3/8". This results in pedal travel increase of .750" with a 5:1 ratio, or .9" with a 6:1. As I stated previously, using a 1"
is doable in most cases with minimum effort. The resulting higher pressure output with a 1" works better with common disc/drum systems by slightly lowering the pedal effort.
I
know converting to a dual master cylinder is the
best hydraulic brake upgrade you can make, but does require some thought and extra effort.