Correct clutch Master?

[Robert J. Alder]

I'm re-doing a Lola T-620 FSV VW Water cooled 4-banger. It's mated to a a MK9 Hewland with the standard VW throwout bearing arrangement operated by the usual outside VW lever activated by the ubiqutous 5/8" Girling slave. The clutch is a 7 1/4" Tilton with orange springs (heavy, I believe).

I note the clutch master cylinder is .75". My concern is that this combo is going to have a clutch pedal requiring a gorilla to push it in.

Does anyone know if that .75" master is too big or what diameter master would be best for this combo? I'm guessing I should drop it to 5/8" or invest in a fitness program for my leg.

[SCOTTY81]

Bob,

Go with the 5/8 MC. This will give a straight 1 to 1 ratio.

[kea]

The normal Girling external slave cylinder has a 7/8" bore.
The option has a 3/4" bore.

[revtom]

As Keith notes, the slave is usually 7/8's. In my SV, with same clutch, etc. I found a much better clutch feel by going with a 5/8's master, instead of the 3/4's the car originally had.

[Robert J. Alder]

That's what I thought. Actually the slave is .75 " (not 5/8" as I incorrectly stated). In any case, sounds like I should just go ahead and use a 5/8" master. Thanks for the help.
Anyone have an old 5/8" Girling master they want to unload?

[kea]

Don't forget, there is a .70" Girling also available, if you want to only slightly increase the needed peddle travel while slightly decreasing the pedal effort.
Old master??
Why take the chance.

[Albatross]

That outside VW lever takes an awful lot of strain and often begins to crack under that strain. Why orange springs? I know that a few of us just happen to carry an extra outside lever just in case. Presently, while I carry an extra lever in the tool box, the one presently on the car has been subtly reinforced by adding a 1/8 - 3/16 top and bottom rib to the lever where it necks down.

[kea]

The clutch arm on my 1979 Ralt S-Vee came with a reinforced arm and I've modified a number of others over the years. A simple strut on it's bottom side.
Once modified, it holds up quite well.

[Robert J. Alder]

To be honest, orange springs because it came with the car. I'm doing a restoration and the brand new Tilton assembly (with orange springs), still in the box, came with the project. I wouldn't have bought it otherwise. In fact, I might even try to sell it and get the Tilton with the "normal" springs.

Maybe the old clutch was likewise too strong (don't have it to compare) thus contributing the thrust washer failure???? There was evidence of thrust washer failure on the engine.

By the way. I need another lever. Any idea of where to get one? The one on the car doesn't clear the bell housing like it should and thus fouls the big return spring against the bell housing. In fact the prior owner just left off the lever return spring. (Duh!) That too could have contributed to thrust washer failure since any slight riding of the clutch pedal would have translated into unnecessary thrust washer wear.

[butch deer]

Just remember the smaller the diameter of the MC the less effort-longer throw to move the same amout of fluid. Wildwood also makes a line of MC almost dimensionally identical to girling at roughly 1/2 price new.

[Bob Clark]

To be honest, orange springs because it came with the car. I'm doing a restoration and the brand new Tilton assembly (with orange springs), still in the box, came with the project. I wouldn't have bought it otherwise. In fact, I might even try to sell it and get the Tilton with the "normal" springs.

Maybe the old clutch was likewise too strong (don't have it to compare) thus contributing the thrust washer failure???? There was evidence of thrust washer failure on the engine.

By the way. I need another lever. Any idea of where to get one? The one on the car doesn't clear the bell housing like it should and thus fouls the big return spring against the bell housing. In fact the prior owner just left off the lever return spring. (Duh!) That too could have contributed to thrust washer failure since any slight riding of the clutch pedal would have translated into unnecessary thrust washer wear.

Make sure there is a pedal stop on the clutch pedal!!! That will knock out the thrust washers fast if you don't have one. You should see what happens to the the pressure on the clutch when you go too far.....

[kea]

I normally don't use nor have I seen many use on the Mk series gearbox with external lever, a return spring. It's not like the heavy spring that VW used.
Thrust washer wear normally comes from long periods of holding the clutch pedal down (like on the grid), not completely removing your foot from the pedal or over stroking the diaphram springs.
I also shift (upwards) without using the clutch.
In which case, it's just little less time each shift spent loading the thrusts.

[Robert J. Alder]

Make sure there is a pedal stop on the clutch pedal!!! That will knock out the thrust washers fast if you don't have one. You should see what happens to the the pressure on the clutch when you go too far.....

Thanks for the reminder and the diagnostic re: thrust washer. I well know to set them up with a stop since over pushing a Tilton is bad news but hadn't thought about that (done badly) could also have contributed to the thrust washer failure. The prior owner could have also done that badly. Nothing else on the car was setup correctly. You wouldn't believe all the things these characters did wrong, stupid, or just plain ugly. It's been an adventure. but the car will come out nice when done.