Hydraulic clutch cylinder sizes?

[Michael C Henry]

I had problem with my clutch asperities in my past. My car came to me with a 7/8" ID Tilton master cylinder. It had very little free travel and barely enough clutch release. The adjustments got away from me and the throw out bearing seized up taking out the pressure plate forks and damaging the aluminum flywheel. I sent the fly wheel and pressure plate to McLeod to have them repaired. I had the flywheel cut for a full 12" clutch heat shield and had it installed. the pressure plate came back like new. Why I reinstalled the 10 1/2" clutch disk, I don't know. I had installed a new Tilton 15/16"ID master cylinder things were better .
Several years later I started chasing the free play adjustment only to run out of adjustment room. I made a new adjustment rod. I changed to a larger 1" ID master cylinder. Still the free travel kept disappearing. Then I removed the slave cylinder and discovered it was rusted and pitted inside. I went to the local clutch and brake store and showed the man at the counter what I had. He left and came back with a new boxed slave cylinder with bright finish and new rubber bellows Turns out it was an OEM slave cylinder all along. I installed the new slave cylinder and my new adjustment rod, I had made. I made and installed a heat shield for the slave cylinder. I installed a new 12" McLeod clutch disk and throw out bearing Other than the foot pressure it take to operate it's great. I have to wear shoes on the small AC pedals. I have lots of free travel and full clutch release. When you go to a larger master cylinder you gain volume and give up leverage. The pedal travel can't change. The slave cylinder has to move far enough to have free travel for the throw out bearing to escape the moving clutch and still push the throw out lever and bearing enough to have full clutch release.