360850 Throwout bearing force and travel vs. pedal force and travel

[awatkins]

I'm setting up the clutch linkage for a car using a 360850 pressure plate.

I have a lot of freedom with slave cylinder diameter and cluch arm length. In order to decide what ratios and lengths to use I'd like to know the typical travel for the throwout bearing moving from just completely engaged to just fully released, and what would be the maximum force exerted by the throw-out bearing force during that travel?

Also, in general what do you consider to be a moderate pedal force for operating a clutch like this, and what range of force is considered "heavy".

Obviously what I'm working up to here is deciding what overall mechanical advantage my foot should have over the throwout bearing, and from that determing arm lengths, cylinder diameters, etc.

Thanks,

Alan Watkins
San Diego, CA.

[BillyM]

I have a lot of freedom with slave cylinder diameter and cluch arm length. In order to decide what ratios and lengths to use I'd like to know the typical travel for the throwout bearing moving from just completely engaged to just fully released, and what would be the maximum force exerted by the throw-out bearing force during that travel?

We like to see between .100" to .150" freeplay between the face of the bearing and the fingers on the pressure plate. From there you need .500" of travel once the bearing touches the fingers for a clean release.

Also, in general what do you consider to be a moderate pedal force for operating a clutch like this, and what range of force is considered "heavy".

40 # at the pedal is considered moderate. 80# would be considered heavy.

[awatkins]

One more question: I'm using a Mcleod throwout bearing 16525 (Big Block Ford to ZF transaxle) and that bearing is listed as "constant running". My Girling slave cylinder has a light spring behind the piston, so can I run the bearing in constant (light) contact with the fingers? That is, zero free play?

[BillyM]

Yes, Yes & Yes.

[awatkins]

Great! Thanks. This forum is a godsend.