Clutch/flywheel explosions...let's hear some stories.

Don't know where your drawing the line as to being "modern", but the Chalenger that was in my shop was within the last 3 or 4 years and the trany blanket was less then a year old at the time.For those of you not understanding, a cast iron bell is just one small step above a cast (or any other type) alumium bell. For a compairison, a steel safety scattershield is several steps above the cast iron bell. Somewhere between the scattershield and a cast iron bell is a 1/4" plate welded to the trans tunnel. But the plate welded to the tunnel will not contain the fragments like the scattershield will, and we have all read where the scattershield has failed to contain the fragments when the bolts are ripped out of the motor block. Even with all the pictures and the horror stories seem as some are still not comprehending the power of a clutch/flywheel when they fail. Lets see if I can shed some light on the subject for those of you still not understanding. If you intend to rev your motor over 4,000 rpm (ever) or intend on power braking your auto trans (ever), BUY A NEW SCATTERSHIELD for your manual trans or a NEW SCATTER BLANKET for your auto trans. When you put your scattershield on your motor, also put in the 1/4" block plate and install it with grade 8 bolts. Broken car parts and messed up cars are part of racing, broken or missing human parts should not be. Be safe, life is already too short. Gene

 

All the tri-five Chevy stories in this thread are kinda freakin' me out tonight! This ol' gasser of mine has some serious engine setback with the engine shoved back halfway under the dashboard. I'm running an ancient RC Industries scattershield from the early sixties. Looks like aluminum but its really Manganese-Moly. A very heavy, thick-walled casting that says NHRA-AHRA approved. I really don't think that it's legal anymore because I think NHRA now requires a stamped steel scattershield these days.

 

I think it's the current issue of Super Rod, it might be some other rag, but anyways, there are pics of a Mustang that blew the clutch at 7500, and another pic that shows a pair of scattershields puropsely blown up by SFI. Scary shit. The caption on the one says that SFI purposely "cripples" the flywheel, and then causes it to let go at 8500 RPM. The SFI approved Lakewood in the pic held the explosion, but you could count the ring gear teeth in the aftermath. Look for it at the news stand, it's a sobering pic.

 

Maybe it's due to just having been injured in an accident, but these stories are FREAKING ME OUT!!

Is it possible to drive from the back seat?

 

Don't sweat it Coop, just run a scattershield. Oh yeah, if you are doing a clutch job be sure to inspect the flywheel and if you see heat checking (surface cracks) have it re surfaced.

 

This is really a good topic to make people aware of what can happen. I have been telling some of my buddys about the possibility of clutch & flywheel explosions but they think im Mr overkill buy using a scattershield & steel flywheel in my ride . I guess I just like my feet attached to my body...LOL

 

Regarding aluminum bellhousings: climb up onto a 10-foot ladder, raise the bellhousing over your head and hurl it at the concrete floor below you.
I don't see it surviving.
Cast iron is brittle. It will not stretch or deform--or absorb energy. It cracks, chips and breaks. In a clutch explosion, you've now added the material of the bellhousing to the mass of fragments coming through your car.
Formed steel is going to absorb the energy and contain most of the fragments. It shouldn't become part of the problem.

Blow-proof bellhousings aren't expensive.

It seems like something that used to happen a lot more in the old days, before the technology caught up to the flywheels. I won't put one on my '62 Suburban, because that thing will never be shifted hard or aggressively...and the engine won't ever be wound out. I wouldn't run my '57 gasser without one, and I have one for the 283 I'll be putting in my '56 too.

-Brad

 

You and me both! I've got an aluminum bellhousing. Thank God I drive like somebody's grandma. I usually shift around 4000 RPM, 5000 if I'm feeling "hot roddy."



-Dave

 

I've been seeing lots of scatter shields at swap meets that are past the certification date but still undamaged, so guys replace them rather than send them back for recert. Those should still work for most street engines, offering lots of protection for not much money. It's cheap insurance for anyone the thinks of driving their car like a hot rod.

 

If you go the route of using a used scattershield check the runout before
installing. If it's out it can be adjusted with ofset pins.

I have seen used Lakewood runout in the 0.020 range and that will kill a
bearing. My new McLeod came with indicator marks on it and runout of less
than 0.003.

 

somewhere in San Antonio, there is about 1/3rd of a nice flywheel embedded into the asphault.

My Friend Turtle (if you've been to the round up, you've seen his car. 50 Chevy, Flat roofed, back halfed with a big block and a 6 speed. and a couple holes in the hood and cowl. it's no beauty, but I digress.) was goofing off- not racing, just doing burnouts and such.

when the flywheel let go, it tore that car apart. wrapped a big tube header around the frame- it looked like tinfoil wrapped around a 2x4.

the dash- screwed. cowl, screwed. it took ALL the pedals out from under his feet. if he hadn't been wearing Steel toes, he would be less all of them on his right foot. the ENTIRE mounting boss on the back of the block was just gone. it almost looked like it was supposed to be that way. 1 side of the frame was completely severed. firewall looked like a fat girls ass.

he eventually re-built the car on a different chassis, which explains alot of how the car is today.

every time I remember carrying that scattershield ALL THE WAY ACROSS the springfield swap meet, I think to myself. "It was worth it." I also just ordered a billet flywheel and a centerforce clutch. I figure that if I kill it, at least my pile of rubble will be an expensive one, and I will be able to WALK over to it an show my friends.

 

As others have said, this post kinda freaks me out. I've heard stories about clutches blowing up, but these pictures are all too graphic.

I'm using a NPG A833 trans. (3 speed & OD) out of a '84 Chevy p/u behind a 327 in a 46 Chevy p/u. The trans. bolt pattern is MOPAR and, of course, the aluminum bell hsg. is SBC to MOPAR trans. I don't find any scattershields available for it. Is the only choice installing 1/4" steel plate on the bell or floorboards or can a conventional scattershield be reworked to fit? Anybody ever done it? I guess I don't care to end my life without legs.......

 

I have heard of people loosing there leg and explosions from putting the clutch in backwards (whatever that means ) Don't know how true it is though

 

Hey, I carried it part of the way!

I can't remember who told Angie that story when I wasn't around. I think it was Tyler. Anyhow, she came and told my how I had to get one of those "safety protection shield so you don't lose your toes or your balls goes over the transmission type thingies". So I got one ordered up right away and put it in the coupe.

 

I think the year was 1966 and one of my fellow racers at Pittsburgh International Dragway decided his Tri-Power '64 GTO was going back to street duty rather than race and street. He still wanted to race and found a Austin-Healy 3000 that had a SBC in it. It was a 301 with solid lifters so a scattershield was in order. He put a new clutch disc and pressure plate in and changed the bolts holding the flywheel to the crank. I think at the time a SFI flywheel wasn't required. He did say the flywheel had heat check marks on it, but it was going to be changed out over the winter. The scattershield was already in the car since it was raced before. It was the 2-piece style that bolted both halves together along some fabricated frame rails. He ran the car one night and made quite a few passes. The following weekend he showed up to race, and on his first pass, the flywheel exploded. He lost part of his right foot and all his toes. One part of the flywheel went through the fence missing people who were in the area and hit one of the spectators cars. I was working that night and wasn't there, but friends said there were thousands of pieces of the flywheel/pressure plate/disc.

 

I've got the same trans/bellhousing sitting on my shop floor. I THINK Lakewood makes a bellhousing to mount a Mopar trans behind a Chevy. Check their catalog, or better yet give them a call. I'm reasonably sure there is an a-dapter-kit for that conversion.

OR, you can also look around a little more for the same trans with a Chevy bolt pattern. I just got one of those. The retooled the mounting on the trans case, so it bolts to a Chevy bellhousing. I'm putting it in my '62 Suburban, which uses the old-style bellhousing with engine mounts, so I couldn't use the other aluminum bellhousing. Again, it's going it a tow rig/daily driver, so I'm not worried about the clutch in it blowing up. But if I was putting it in a hot rod, I'd dig a little more for the Lakewood.

-Brad

 

Ive also heard of using conveyer belting being legal for Nascar Super Stocks in the 1980's at the local roundy round track

 

Does anybody have the NHRA rule for this handy? I saw it last night searching another forum, but am having trouble finding it now. It has information on requirements for making your own scattershield if a manufactured one is not available for your setup.

Thanks,
Kurt

 

I hate it when that happens!!

 

So the Cast Iron Scatter Shields can fail that badly, and just turn into more shrapnell?

Like the Ansen I posted a pic off earlyer?

I might have to rethink the setup I am putting into my little Euro-Ford.
It is getting a high RPM Motor...

 

How about stock type harmonic balancers....they will come apart on you too! I saw one brake on a FED, not pretty.

Craig

 

hi Kev

You will like this although there are not a lot of Americans who will relate to the vehicle. A freind of mine had a hot MK 3 Zephyr which would stumble a bit when subjected to idling around town. He was on his way bout of town , ( going up the hospital hill if you know Nelson ) so he gave it the big rev to clear tke engine and the flywheel came off and came thru the bell housing and thru the floor narrowingly missing his left foot!

 

Exceptions to this rule: Certain engines are not required to have a shield when they are normally aspirated and gasoline burning, and certain engines must use a steel billet flywheel in lieu of a flywheel shield. Some engines for which an SFI 6.1 or 6.2 Spec adapter shield is not commercially available, must be equipped with a flywheel shield made of 1/4-inch (6.35 mm) minimum thickness steel plate, securely mounted to the frame or frame structure and completely surrounding the bellhousing 360 degrees. The flywheel shield shall not be bolted to either the bellhousing or engine. The flywheel shield must extend forward to a point at least 1-inch (2.5 cm) ahead of the flywheel and 1-inch (2.5 cm) to the rear of the rotating components of the clutch and pressure plate. Other engines, where an SFI 6.1 or 6.2 flywheel shield is not available, may use an SFI 6.1 or 6.2 flywheel shield from another application and mount it to a motor plate which is mounted to the engine block at all available bolt holes. The FIA Drag Racing Commission will establish a list of such exceptions, to be published annually in the FIA Bulletin.

 

Back in 1960 while running at the old Houston Gulf Freeway drag strip near Dickinson, TX, I blew a clutch in the dragster. I was sitting on the line ready to go. The flagman pointed at me, I naile the throttle, he pointed at the other car and just them wham..........out it came. Flywheek, pressure plate, disc,,,the whole thing. I had a scatersheild, but it flew off also. One piece hit the car I was running, a blown Pony gas dragster and knocked a chunk out of his brand new MT valve cover. He was pissed. One piece hit the flagman and sent him to the hospital and one piece broke the window out of the timing tower. I was unhurt, but spooked for sure. We went to a solid one piece scatter shiled after that.

 

Kev,I must have been with you when that Chev 'spat the dummy' .I remember vaugely that the guy driving owned the engine and the car was larry Knights Fiat altered."Once a Knight.."
Contrary to rules he was running a Stock flywheel,a cast iron one..The rules called for steel only.He was also banned from racing at Meremere .
Then there was Ian Rainbow in Auckland who had a red hot '38 chev Coupe,running a 327 ,again with a stock flywheel ,it let go and cut the car in half....
A couple of years back I was forced to sell my hemi,amongst the spares was a stock flywheel I was going to use as pattern to make a lighter steel one.
The new owner proudly informed me he had bolted this shitty item up to the engine......
This is an engine that took me to 121MPH in first(1st gear!) on the OZ salt...
I notice a few of the guys mentioning their explosions have all used the stock flywheels,it's a dumb idea in this day and age.A steel flywheel or a alloy flywheel is miles better than some old cracked item with a few hundred thousand miles of abuse on it.
Regarding trans blankets,when you go through scrutineering they check the dates on things like trans blankets and seat belts.
On the lakes you are expected to replace every few years,so don't be tempted to buy that fleabay or swap meet item to save a few bucks.

 

While watching a street race in the early eighties, a guy in a '55 sedan with a bbc in it lost the crank bolts and the flywheel/ clutch asy. buzz sawed its way out the cowl and hit a spectator between the legs. The heat from the flywheel carterized the wound so there was no blood but the guy had no pants on when we helped him up off the ground. If the flywheel were to have been another 1/2" higher he would have been castrated as well!
We did find the parts about a half mile into a lettuce field an hour later. To this day I still can't beilve that of all the nights that the cops did'nt show up this would be the one.

 

Had to add this pic to this thread, I sure hope it's a rear engine car! (note, clutch can top left )

 

Scared me bad enough when a pressure plate disintegrated on me about 25 years ago in a '55 Chevy pickup with a bone stock 2 barrel 283 and 3 speed as I pulled away from the drive-through at Hardee's on Thornton Avenue in Dalton GA. Probably under 800-900 RPM. The cast iron bell housing held, no damage to the truck body or my body which is much harder to get parts for, but it did break a rear motor mount (old Chevy with bellhousing mounts). Rebuilt pressure plate that had been in it maybe two or three weeks of nothing but normal driving.

 

When I was in high school one of the "older" hot rodders had a 65 galaxy 427 4 speed. One night he was showing off down town and stopped at the light for a road headed off the cruising loop, at the green he launched and they guy riding with him said the tach went past 7000 when he went for second and missed. The whole mess went through the floor, firewall, and cowl. The windshield and dash trim parts were busted too. Both driver and passanger went to the ER with lacerations to the legs and feet.

Few years later I was riding in a 74 chevy truck with a 400 and an M-21, The guy driving went to do a burnout in the driveway of a friends house and dumped it at about 6500. The cluster gear came out the bottom of the case, and the pressure plate came through the stock bell housing, we found pieces stuck in the holes in the floor. This was a McLeod borg & beck plate with a bronze puck disk too. Oddly enough the factory 400 flywheel held, and we were not injured.

I don't care how un-traditional it is, I run a scatter shield and drive shaft loops in anything more than a daily driver. Any injury you suffer from this stuff is going to cost way more at the ER than the few hundred for a proper housing.

 

good god this is some freaky shit...