Clutch Selection for the 460 CRATE

[cobrashoch]

MY EXPERIENCES----------
After fooling around with almost all the big clutch setups and a 31 spline toploader, then switching over to a automatic some comments.
Clutch Pedal Stops---
A centerforce clutch needs little throwout movement to actuate the pressure plate. You will most likely need to put a pedal stop on to keep from going over the pressure plate centerline. This will keep Centerforces as well aftermarket diapram clutches from sticking on the floorboard. A pedal stop will also keep you from bending a finger on a Borg and Beck 3 finger clutch. A block of wood on the floorboard can be used for the mechanically challenged and emergencys.
Diapram Pressure plates-----
Diapram pressure plates are limited to about 26 or 28 hundred pounds of clamping force. A Centerforce pressure plate uses weights to increase clamping force about 200/250 lbs at high RPM's. A lot of racing types around these parts take off the weights. About the practical street limit on a street car of about 2800 lbs is about 450 horsepower. Centerforce pressure plates work well with stock factory disks too. Any more power than 450 requires a ,,,,,,,

Borg and Beck (3 Finger) pressure plates.---- Skys the limit on clamping force but the 3200lbs limit I would put on most Cobras are about all thats needed on most a street cars. 3200lbs will also wear out you left leg too. Higher pressures also cause hydrolic throwout bearing problems. Borg and Beck PRO pressure plates are what I recomend to all that listen to me, because they have heaviier case castings, are rebuildable, and have zero disk deflection when you drop the hammer. All pro clutches have at least 12 bolts though, and require their own 12 bolt flywheels. I can't stress this enough, in my eyes a pro clutch is the ONLY way to go on a street car that takes weekend racing abuse. You can also run slightly lighter clutches with them. Been there, done that. All big inch strokers and big block cars need to look these guys over. Yes, they cost more too.

Double and triple disc clutches - For racing only, street cars and even most road racers need not apply here.

Transmission Hydro. Throw out bearings. (inside bellhgousing type)---- Tiltons, designed for Centerforce pres. plates only. Do not use with any more than 2800 lbs pressure plates. You will blow seals and they will pump (leak) on clutch ingagement. On McClouds make that about 3000lbs. Understand, they will ALL work for a while if you abuse them,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

External slaves/actuators for Throw Out bearings.
Only way to fly- but they are harder to fabrcate up and require a fork thats hard to find. I welded up a bracket on my scattershield to mount one up, but my NHRA tech guy wasn't impressed, and rejected my shield handywork.
cobrashock