Clutch Pack Questions

This is my first posting on the site, so everyone take it easy on me. I notice that when a clutch pack is taken out of the car the discs and floaters are not flat (even if they were ground before the run). They tend to warp (dinner plate) towards the hat/pressure plate. Are the units designed to do this, or is this a design flaw in the clutch unit? It would seem to me that this takes alot of energy (horsepower) to bend the metal discs and floaters? Also, the clutch wouldn't be as consistant as if the plates stayed true and flat. Does anyone have experience with a clutch unit that warps the discs / floaters little or none? Or has anyone pre-ground their discs / floaters with this "warp" already built in?

 

The warpage is an un-desirable effect of the extreme heat and pressure generated by the horsepower of the motor and the load the clutch carries. The floaters have been made thicker over the years to minimize the distortion, but there doesn't seem to be an easy answer. That is why the clutch packs are changed or re-ground every run.

 

Back in the early 70`s, i ran a BB/A With a crower glide two disk, back then shaffer was building clutches ,they had a floaterplate that was round it had holes in it, for the stands to go thru, i used that set up for years, never warped any thing just wore it out then they stopped making that type of floater and you know the rest of the story. my point is for the sake of weight the clutch people made the floaters with scalloped ends and thats why they bend . to many ends for the heat to go out of , instead of one continuous ring. Gene Sr.

 

Today floater disks are manufactured two different ways. The less expensive ones are made by stamping them out of flat stock, then ground to the proper thickness. These disks warp more because the grain pattern runs across the disk. The more expensive floaters are machined from round stock with the grain pattern running from the disk’s front to back making them more stable.

PICK YOUR POISION, spend less money up front, then, when surfacing, more material will need to be removed. More money up front, then, when surfacing, less material will be removed. The thing to remember is all disks warp from the abuse they receive, just make sure your getting what you paid for. Ask your disk manufacture which method they use. In the end the cost is about the same, they all have to be surfaced between rounds, it’s just a question of how much, and that will dictate how often they will be replaced with new.

Gene I would like to see how the old style Shaffer floaters would hold up in today’s cars, (read torque/hp) even with the additional weight I believe they might perform well enough to add some et/mph. Especially in today’s fuel car, where the disks really get abused.

 

I miss spoke, thay changed the way they are made for two reasons, # 1 the weight #2 the old floaters wont fit in the bell housings any more ,( to big in diamater) after they made us put the 1/8 in ring inside, so am i dateing myself or what? just a tought it might work in a BA/D they use a 10 in clutch , pleanty of room.,may be even a 10.7 funny car, back then we used a 11 in .

[ January 25, 2005, 10:00 AM: Message edited by: ttutubono ]

 

The new Trick Titanium can we bought last June came with two 1/8th inch rings (per the rules). I really never measured the inside diameter of the rings but still has plenty of room for the 10.7 crower we run. (The bigger the can the more titanium used the more you can charge LOL)

I wonder which clutch (new or old) took the most abuse. “Back when” did you have any way of telling at what RPM/location on the track the clutch would lock up?

As you know in IHRA funny car, most are locking them up half way through low gear, and trying to keep them locked at the gear change? Less slip = quicker times = less wear and tear on the plates. Maybe?

 

we never locked up the clutch, the sooner you lock it up "drag the motor down" the less power your making (low rpm,s no boost) thats way they call it a slipper clutch. at least thats the way i ran ours. Gene Sr.

 

Funny Car Summer - One of the reasons that floaters warp after a run is partly because of your aforementioned "design flaw" in the hat and pressure ring (donut) design. The flaw is in the location of the clevis that holds the levers. The pressure applied to the donut through the clevis is not in the center of the donut and floater on most clutch units. Therefore, when the lever applies pressure towards the top of the donut, it is trying to bend the donut and the floater. Over time, depending on the material used and how it is made, your donut will warp as well.

To see what I mean, check out the location of the clevis on your unit and see where it is located in relation to the center of the donut and your floater.

 

Paul is correct. If you don't keep the donut flat
it will cup and so will the floaters.

 

Hey Paul have you ever done one of these things before, you kinda talk like you know what your doing

 

can you tell me who has the best clutch out there right now for top alcohol with a blower , i know gene likes the crower glide .

 

Fat head Joe, my e mail is down, i think i got a virus,i`ll give it a shot of penicillin, ( i once met a chick that was willin, now i`m usin penicillinn, thats from the 60`s red fox ) I`m back in a state of limbo , i`m not racing with any one (yet) my brother is having ron zavarella drive for him, you must rember him from the hot rods from hell days, if i can help in any way let me know, my house goes on the market within 2 months, I might be down there sooner that i thought, rember to have fun racing, Gene Terenzio Sr. P/S if you come across a crower glide 6 finger ,and send me the hat i`ll fix it up for you and you will never go back to a peddal clutch! lots less wear and tear on the motor,trans, and rear end, and it will leave harder or just as hard as a peddal clutch.

[ January 30, 2005, 11:05 AM: Message edited by: ttutubono ]

 

I wanted to thank everyone who replied to my message / question. The brain trust that is on display here is impressive. It was my thought that the pressure applied to the pressure plate and the lack of center (middle) support lead to the warping of plates. Thank you to P. Lee for pointing out the information about the location of the levers. Two follow up questions. Does the fact that the levers place force on the clutch pack in a rotational manner (as the fingers leverage outward) have any effect on the warp problem? Does the location of the static springs (from the center of the clutch)in relationship to the levers have any effect? Thanks again to everyone for their input!

 

Does the rotational speed of the clutch disc's come into play i.e. more speed on the outer diameter versis the inner diameter of the disc creating unevan heat in the floaters?

 

Was thinking more about the clutch warping, maybe because the clutch is disingaged and free to warp wile being towed back to the pits,::::just for the hell of it maybe some one might disconect the driveshaft coupler at the end of the track ,it has to be done anyway, and have the clutch ingaged wile towing the car back to the pits, just to see if it makes a differance? i know the hot spots will be there, but if it dont warp its less grinding,and more use of the parts, less money, on clutch stuff. Gene Terenzio Sr.

 

That is the way we tow ours back to the pits coupler out clutch ingaged and it does the same thing. Dave

 

dmwells, Do you have a way to cool the clutch wile your towing it back to the pits?, If its still hot when you take it apart it will still warp. Gene Terenzio Sr.

 

Why do you have to disconnect the drive shaft?

If you have a Lenco transmission can't you just pull it out of gear and tow back with the clutch out?

Gary