Exploding cutch/pressure plate issue

[Kitcat]

I have posted this issue on Slowmove's engine rebuild thread but think it deserves its own thread. I will attach another picture here of my failing pressure plate. My question today, is, for those of us with Zetecs and Caterham 6sp transmissions, what is the best insurance against this potentially catastrophic failure? It is also relevant to anyone one with a se7en and a high rev-ing engine.

 

As Skip and others have noted, my pressure plate and clutch were close to exiting the bell housing and my ankles were the likely to be removed in the process. That was my mechanics comment as well:"Man, you don't know how lucky you are...."

 

Some have mentioned a SFI rated clutch system. But there don't seem to be many (any) for this set up. Others says a bell housing wrap/scatter-shield. Again, rather than reinvent the wheel, what is out there already. Since our Caterham 6sp apparently use the T9 bell-housing, someone must have an off-the shelf item?

Edited July 16, 2015 by Kitcat

[xcarguy]

Mike,

 

Try shopping these. Even if nothing is readily available, I would consider a bespoke unit. Several years ago, a buddy of mine had the clutch assembly let go in his 57 corvette at 9K during a 1/4 mile run; it scattered shrapnel all through the tunnel and footwell. Luckily, he walked away unhurt, but he never ran again without protection. You can't put a price on your health.

 

 

http://americanpowertrain.com/p-29455-bellhousings-bell-adapters.html

 

http://lakewoodindustries.com/drivetrain/bellhousings.html

 

 

http://www.deist.com/bell-housing-blanket-p-99.html

[coffee break]

Of the clutch explosions, under what conditions have they occurred? Standing start?

[scannon]

The ones I have heard about occurred at high rpm speed shifts.

[inchoate]

My Cat came to me with a rather robust scatter shield. I was honestly thinking of getting rid of it as I have no intention of tracking the car, or really wringing it out for that matter. Now I'm thinking maybe it can stay. Better to have it and not need it than to need it and not have it.

[BruceBe]

I have posted this issue on Slowmove's engine rebuild thread but think it deserves its own thread. I will attach another picture here of my failing pressure plate. My question today, is, for those of us with Zetecs and Caterham 6sp transmissions, what is the best insurance against this potentially catastrophic failure? It is also relevant to anyone one with a se7en and a high rev-ing engine.

 

As Skip and others have noted, my pressure plate and clutch were close to exiting the bell housing and my ankles were the likely to be removed in the process. That was my mechanics comment as well:"Man, you don't know how lucky you are...."

 

Some have mentioned a SFI rated clutch system. But there don't seem to be many (any) for this set up. Others says a bell housing wrap/scatter-shield. Again, rather than reinvent the wheel, what is out there already. Since our Caterham 6sp apparently use the T9 bell-housing, someone must have an off-the shelf item?

 

Hi-strength Loctite on the PP bolts. I would bet that the PP bolts were backing-out, causing the flange of the PP to slip and work against the shank of the now-loose bolt. And, I know what you might be thinking - no, we did not install the clutch on that engine. The engine/gearbox came as an assembly from Caterham USA, and then installed in the car :-) Those bolts have a serrated flange, but high-strength Loctite is a must for track cars, especially those with Aluminum flywheels.

 

Cheers,

-Bruce

[James A]

I think Bruce has the answer, pressure plate bolts should have Loctite and the bolts should be torqued to specification. I know the ACT clutch kits have the following instructions (I am paraphrasing): Use high temperature thread locking compound, use new pressure plate bolts metric grade 10.9 or SAE grade 8 bolts, torqued to: 10mm - 50 ft-lbs or 3/8 x 24 to 48 Ft-lbs.

We have never had a failure of the pressure plate on the race car or autocross car following these instructions. We have used ACT clutches and Fidanza flywheels.