[bwcobra15]

Originally Posted by PaulProe

Bobby,
Number of things:

1) are you getting full stroke with the longer pedal. I suspect it is bottoming out before you move the mastercylinder puck to its limit

2) What size is your slave cylinder? Using a .70 diameter mastercylinder for a clutch is extremely rare. You probably aren't pushing enough fluid

3) Most pressure plates require 1/2" movement at the throwout bearing. With the Ford clutch lever, that translates to about 7/8"-1" at the end of the lever, where the slave cylinder attaches - meaning the slave cylinder has to move that same distance. If your slave is any bigger than the master cylinder diameter, you will have issues.

The Wilwood slave is 7/8" bore. To move it 1", you need .6 cubic inches of fluid. The Wilwood masters used on Hurricanes have 1.25" of stroke. To get that much fluid, you need the 13/16" bore and it needs to move full stroke. It would be better with a 7/8" bore but Wilwood doesn't make one in that style.

With less than full movement, you reach a point the clutch releases but doesn't let the disc free wheel. Two issues - the transmission won't shift right and the clutch will wear quicker.

Remember in school - why do I need this math, I'll never use it

Very good info, Paul -- reminder: I have the Tilton hydraulic TOB, so no slave cylinder or clutch lever arm I"ll confirm which M/C I have tomorrow night when i get back home.