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

Discussion in 'The Hokey Ass Message Board' started by Kiwi Kev, May 28, 2007.

  1. i had a sfi issue one day in columbus,oh. the drive train was a blown hemi on 50 percent. bruno convert/lenco three speed. the fly wheel was a ati. i had 1/2" bolts going from the converter to flywheel grade eight lock tighted. duing the burnout the bolts broke. anyone who has raced at columbus knows how far away the stands are on the right side of the track. the bolts hit the track and flew over the wall over the grass over the return road and up to the top rows of the stands. a guy was sitting there with a camera around his neck. one bolt went through the lense and out the back destroying the camera. the bolt hit his leg and burned it slightly. needless to say when i got back to the pits the nhra golf carts were already there. they inspected the car. all sfi stickers were there on flywheel and bell housing. they asked why there was no cover on the bottom of the bell housing and i told them they dont come with one and i cant modify it due to your rules. nothing came of it. so you can have all sfi parts and still have a on track incident. about the same time my friend with a similiar set up had the same problem. we both went to 5/8 bolts and never had a problem again. at the grove years ago a fuel dragster blew a clutch and pieces flew into the crowd killing three. my friends hemi gtx blew a clutch and parts went through the headers and floor. i was driving the original candies and hughes 65 funny car and rolled a sprag in the 727 when it blew parts went through the dash and frame and right side front fender and it had a shield on it. removal was easy we pulled the drive shaft and it just fell out. when they first asked me to drive the car i told them i wont unless it had a shield. good thing i did.
  2. elba
    Joined: Feb 9, 2013
    Posts: 624


    I was at the U.S. Nationals in 1965 ( I think ) and a AA/FD had everything blow up. Clutch, flywheel and blower. The spectator stands where a lot closer to the track back then. Shrapnel went flying into the stands on both sides of the track. People were hurt, and spectators on both sides were calling for help. I don't think there were any life threatening injuries, but it was scary.
  3. GeezersP15
    Joined: Dec 4, 2011
    Posts: 555

    from N.E. PA

    Back in the mid-60's, a neighbor had a 57 Chevy. IIRC it had a pretty hot 327 in it. Rumor had it that it was the fastest car around town. Well, one night he was in a street race, and missed a shift. The clutch and pressure plate let go, and came thru the floorboards as though a bomb had exploded under the car. Shrapnel destroyed the radio, and smashed the dome light, and left a gaping hole in the floorboards. He was on crutches for a long time afterwards.
  4. sasquatch12
    Joined: Nov 6, 2013
    Posts: 38


    Just one for me, and i didn't see it, but about 20 years back firemen responding to a house fire slowed for a red light then as the power again was applied the clutch let go badly cutting the drivers feet.
    Nothing to fool with, spinning flywheels and clutches will kill you if they explode!
  5. ttpete
    Joined: Mar 21, 2013
    Posts: 178

    from SE MI

    In the '60s, I was working at a small independent shop. One day, they towed in the wrecker from the local Mobil station. It was a one ton 58 Chevy with a 283 and a 4 speed truck box with a PTO for the winch. The bellhousing was mostly gone, as was the clutch, and the trans was hanging from the drive and PTO shafts. Surprisingly, there were no holes in the floorpan, although it was beat up pretty good. The engine was hanging on the front mounts because the rear ones were gone along with the bellhousing.

    I asked the owner how it happened, and he said that his night driver told him that he had parked it, went inside, and then it blew up. We had a good laugh about that. He said that one piece had hit a car on the street that was stopped for the traffic light. My thought was that maybe the driver wound it up in granny first or was just free revving it. We put it back together, and it went back into service.

    Later, I worked at Ford Engineering and spent some time working with the dynamometer lab. I saw some spectacular blow ups there, including the Indy engines. Their cell was all burnt black inside from them blowing up and catching fire. Most cells had the operator sitting inside at a console facing the unit that had a bedplate at each end so two engines could be mounted and one run while the other was changed or serviced. It occasionally got a bit hairy sitting next to an engine, even though they'd cover it with a chain mail type cage if they were running things like valve toss. One of the most extreme things I saw was a 427 sitting there with the oil pan blown off and all of the main bearing webs broken out of the block. One operator described being in a cell with a flywheel that came adrift and was roaring around the room, up the walls and across the ceiling.
  6. 1971BB427
    Joined: Mar 6, 2010
    Posts: 6,899

    from Oregon

    This is on my winter list of upgrades to my gasser! Picked up a Lakewood bellhousing to replace the factory Chevy aluminum bellhousing. I've never had a explosion, but figured it's cheap insurance.
  7. khead47
    Joined: Mar 29, 2010
    Posts: 1,762


    Back in 1969 I had a stock 1967 Z28. Showing off I did a big smokey burnout and missed the 1-2 shift burying the 8000 tach. BOOM! Clutch and PP instant grenade. Stock bellhousing contained everything. Young and dumb and LUCKY!
  8. Devin
    Joined: Dec 28, 2004
    Posts: 2,351

    from Napa, CA

    This thread has really got me thinking about something I never ever considered before. I'm about to swap a fresh, hot 327 for a tired 350 in my roadster. I originally was going to reuse my 57 cast iron bell housing, but now I think it would be best to use a scatter shield. I don't think I will have enough clearance at the firewall and toeboard with the traditional Lakewood scatter shield. I was wondering if one of the quick time bell housings that are more tapered would offer the same level of protection?

    Posted using the Full Custom H.A.M.B. App!
  9. 270dodge
    Joined: Feb 11, 2012
    Posts: 742

    from Ohio

    I had a G/SA Dodge ;) that I raced at a southern Ohio track. It was the spring championship race of 1969 and I got caught cheating and put into C/MP :(. I stayed and raced. Did good in MP but later in competition eliminator lined up with a D/G Anglia with Jegs painted on the side! That dude spanked me bad at the half track but I saw a puff of dust and parts come from under his car. He missed a shift and grenaded his clutch. He went through the traps at 42 mph. I went through at 117 mph and he still nearly beat me! Back in the day we wanted to be on the right side of the track because all of the shrapnel went to the left.
    The automatic tranny worries began when the 60 through 62 Mopars lacked good torque converters and resorted to the neutral start. That placed a huge load on the rear Sprague and it would eventually fail. That sent the front drum into a 2.5 to 1 overdrive. The engine at 5000 rpm x 2.5 = 15000. A failure was inevitable. The worst injuries were from the hot oil bath! 250- 300 degree oil= 2nd- 3rd degree burns.
  10. dwrfab
    Joined: May 21, 2006
    Posts: 407

    from Dallas TX.

    The most televised clutch explosion in drag racing history. Jim Nicoll at 230 mph at Indy 1970.
    Don Ross

    Attached Files:

  11. Devin
    Joined: Dec 28, 2004
    Posts: 2,351

    from Napa, CA

    Holy Shit! What were the extent of his injuries or did he even survive? That looks BRUTAL!
  12. dwrfab
    Joined: May 21, 2006
    Posts: 407

    from Dallas TX.

    Only bruised ribs and ankle. Worst thing was the gurney rolled back out of the bus when they took off. They stopped and reloaded Jim back in and took off.
    I am just about finished recreating the car at this time.
    Don Ross
  13. Devin
    Joined: Dec 28, 2004
    Posts: 2,351

    from Napa, CA

    I hope he bought a lottery ticket!

    Posted using the Full Custom H.A.M.B. App!
  14. Is this more of an rpm thing or a power thing? should I worry about this with my tow rig? It has a slow rpm 3000 or so 400hp / 800ft lb diesel?
  15. With some real power especially in a light car, I'd agree. I used cast iron truck bells in everything for years. I was a bug about clutch hardware and torqued everything.

    For the scatter shields, you can usually get some dimensions and mock one up out of old pizza boxes to get an idea.

  16. JB_roadrage
    Joined: Feb 25, 2011
    Posts: 372

    from Caintuckee

    I did that once.. I was street racing a Camaro and my C6 decided to let go at the top of high gear.... put chunks of the case through his windshield... worse part was that was back when I was young and dumb and didn't run a driveshaft loop... talk about a scary ride when the driveshaft hit the ground at well over a hundred, and my truck started to turn sideways.... I swear I don't know how I kept it on four wheels that day, but I've never ran without a driveshaft loop since....
  17. chriseakin
    Joined: Jan 21, 2009
    Posts: 381


    My brother put the clutch disc in backwards on my parents' station wagon a long time ago. Wouldn't move, so we pushed it to the local gas station to get the problem fixed. Mechanic said my brother wasn't the first one to make that mistake. I suppose if you revved it enough it would blow up whether it was backwards or not.
  18. Gene Boul
    Joined: Feb 9, 2006
    Posts: 805

    Gene Boul

    Wasn't a clutch it was a tranny! B&J overdrive not underdrive...
  19. Speed Gems
    Joined: Jul 17, 2012
    Posts: 3,337

    Speed Gems

  20. Mr48chev
    Joined: Dec 28, 2007
    Posts: 29,515


    Thread is so old I had to scroll through it to make sure I hadn't posted on it before.
    Around 1974 I had a 57 Chevy Panel truck with a hot 327 that had Jahn's 12.5 pistons, Engle solid lifter cam, 202 heads and a 2-4 early Corvette intake and carbs. I left the dealership where I worked to go to lunch and at the light was a Mercedes coupe, he poked it' I poke it and the race was on, I was pulling him when I went for second and dropped the whole clutch and part of the bellhousing in the middle of the street. I coasted into a parking lot and checked the damage and the wrecker from work shows up and Robert proceeds to hook up to my panel. Frank Weaver Jr had seen me take off from the light and had heard the clutch go and paged Rober t and sent him after me.
  21. Deuces
    Joined: Nov 3, 2009
    Posts: 20,492

    from Michigan

    Damn!!!!!........ :confused:
  22. jnaki
    Joined: Jan 1, 2015
    Posts: 5,965


    Here is our drag racing build and final end: There have been various parts on the HAMB somewhere in different threads over the last several years. This is a clutch explosion post that fits the new/old thread.


    My brother and I built a 1940 Willys Coupe in the early 1960. After racing our 1958 black Chevy Impala in the A/Stock class almost every week at Lions, we thought it would be fun to build something faster. The 40 Willys was set up to run 6 Strombergs on the 283 SBC motor, Howard Cams flywheel, and LaSalle/Chevy adapter, (LaSalle trans, 4:11 Chevy rear) first and ran well at Lions.

    This set up included the all important legal approved 2 piece thick metal scattershield. This version ran well, but was under powered against those hot local B/Gas super stars. (Pittman, Thompson, Cook, Hirshfield, etc.)

    Found in the Drag News 1959

    The Willys then had a full rebuild to 292 c.i. small block Chevy, Howard Cam plus full kit, Jahns pistons, ported & polished heads, Joe Hunt Mag, with a 671 supercharger and 6 Strombergs on top. It was one of the first 671 kits available for SBC motors.

    The car had red primer, no insignias, Traction Master bars, and black rims with Bruce slicks. With welded in steel plates in the trunk, it ran in the C/Gas class with times in the 12:60’s e.t. during all of July and all day on August 13, 1960.

    We were in the finals at 9:00 pm against the class champion and my brother had a two car lead just past the tower. He was at least 3 cars ahead by the traps, when the clutch blew and exploded the Moon Tank in the cab. Later, my brother told me he tried putting out the fire with the on board extinguisher, it did not work as the fire was too strong.

    The car was on fire going through the traps and my brother jumped out going about 60 mph ( as told to us by the racers on the return road) The car immediately turned right and crashed into the chain link fence on the spectator’s side.

    Everyone nearby, tried over 10 bottles of fire extinguishers to no avail. My brother was put into an ambulance and taken to the local hospital. He had 3 degree burns over 30% of his body and face. The car burned to a crisp, wedged into the chain link fence. Lions was shut down very early with a lot of top eliminator races still to be finished, including the consecutive win streak of the Albertson Olds FED driven by Leonard Harris.

    The next day, Atts Ono and I found shards of metal wedged into the dash, door, glove box, etc, The scattershield was nowhere to be found. There was a huge hole in the floor of the cab where the explosion had ripped open an escape route of flying pieces, the Moon Tank was melted away, the bolts were the only thing left, the glove box door was slightly melted from the heat. We took the burned out car back to Atts Ono’s house for disassembly. Then after an all-day, de-construction, we trailered the burned out car to a salvage yard near Lions Dragstrip.

    The clutch explosion was such a force, that it blew the bellhousing to shreds, blew off the metal scattershield to somewhere and the resulting fire was the melting point of most things inside the cab. At this time period in drag racing, Moon Aluminum gas tanks inside of the cab with a pressure pump were completely legal and most every hot, race car had them nearby.

    After this horrendous event, the rules committee banned all Moon Aluminum gas tanks to the trunk or in front of the motor. Sorry, if this started those ghastly, Moon Tanks mounted externally on later model gas coupes and sedans.


    In that last race, I thought it was Tom Sturm’s C/Gas modified Chevy. But no one can remember. I have talked to Eddy Grist of the Grist Family. He was on the return road with his family after his dad had just made a run in A/Gas. He saw the whole explosion, resulting fire and crash. It was something he will never forget as quoted to me back then. There were other families and racers on this return road, but they remain a mystery.

    Last year at the June 2017 Lions Dragstrip Museum opening event, I talked to the author/editor of the “So Cal Thunder, When Lions Roared”… book. He was a 19 year old in the spectator stands all day, watching our Willys race and win against all opponents. He was impressed. But, at that 9:00 P.M. final race, he described the huge clutch explosion, sparks under the Willys, a ball of fire racing through the cab and out of the windows. Then he saw the driver door open, more flames following and something falling.

    The last vision was the 40 Willys veering toward the spectator’s fence burning and stopping, finally, wedged into the fence with flames coming out of all windows and doors. He will never forget that sight and was giving me chills as he was describing the series of events that took place right in front of where he was sitting.

    From the Vintage Scattershield thread:

    My brother and I were ready to install the 283 SBC /with 6 Strombergs to the 3 speed LaSalle transmission. It was ready and waiting in the Willys chassis. But, he mentioned that we needed to get one last safety item. A run to Reath Automotive at 10th and Cherry Ave, solved the problem to fit to the rules.

    The curved, metal scattershield would bolt on to the bellhousing, while the lower plate would go underneath the housing with the provided brackets. When it was installed, it looked like it would withstand a hand grenade explosion. The modified, floorboard was neatly attached back in place and we were almost ready to go racing.


    According to the racers, this was the best scattershield at the time. No one had those full 360 degree housings as yet. Explosions can be powerful… the results were horrifying…

    If you raced after 1964 and did not suffer a horrendous blowout, thank Joe Shubeck…

    From a previous thread:

    ...If Joe Schubeck’s invention was around back in 1960, we would still be involved in drag racing for many more years to come. We may have still been in the hot rod industry of some kind. His invention prevented many exploding clutches as strong as the clutch could be made, from flying all over the place. It was able to enclose the remaining parts inside of the 360 degree catch-all metal shield. This was a real “scattershield.”

    My hat is off to Joe Schubeck for his ingenious development and that every time I see that red FED, silently, I thank him for saving tons of racers lives from the ravages of exploding clutches and flying metal pieces in all drag race cars. Sorry, you did not invent it in early 1960.


    “I had built my own tubular chassis,”explained Schubeck. “that was the first tube chassis in 1958, and then in 1959, I rounded up a bunch of people that wanted them. So, I found myself in business. I called it Lakewood Chassis Company.”

    "One of the most difficult pieces to construct was the aluminum transmission bell housing. He knew there had to be a better way to manufacture the part and while visiting a fabrication shop in Cleveland, he learned about a machine called the Hydroform."

    "Through persistence and hard work, he developed a die to put in the Hydroform and 20 seconds after the engineer flipped on the machine, Schubeck was holding a gorgeous, seamless, aluminum bell housing. It was a tremendous product. His old friend, Jack Harris knew what it might mean to the industry. Across the country, drag racing was plagued with flywheel and clutch explosions. Chunks of cast iron were flying into the grandstands, blowing cars in half, sometimes proving fatal for drivers and spectators."

    “It was obvious that what I needed was to make a bellhousing out of steel,” said Schubeck, “and Jack Harris told me: “If you could make that thing out of steel and it will contain that clutch, you would have a multi-million dollar product on your hands.”

    "The catch to developing such a coveted product was that Schubeck was going to have to retire as a driver. He reluctantly stepped away from the cockpit, and the move paid off. Before long, he had two shifts going seven days a week, putting skid loads of new steel bell housings on trucks."

    If there are any contacts you may know, photographers that were there in 1960 (April to August), racers, families, drag strip staff, etc. someone may have taken some photos or movies. Please let me know. By the way, after our clutch explosion and resulting fire, the Lions safety committee made it a rule that no aluminum, Moon gas tank(s) would be allowed inside of the cab of any vehicle. Everyone had to move it in front or to the rear of the car.

    Our late friend, Atts Ono, (who was instrumental in helping us get our car ready, was in our pit crew, and helped in the immediate tear down after the explosion) moved his Moon tank in front of the motor, out of the cab, in his own 40 Willys build, later.
    kidcampbell71 likes this.
  23. My experience with a clutch explosion turned out to be minor thanks to a blow proof bellhousing.
    I bought a 67 Fairlane drag car with a 427 tunnel port engine from a gentleman who stopped racing a couple of years before. Engine was in fantastic condition for setting a couple of years. I replaced the old gas and fired it up. Seemed like it was going to be fine, so I trailered it to the drag strip to she what it would do. This would be the first time I had ever run a car down the drag strip before. I was just going to make a pass to check out how it ran. Well, I got up to the lights and left, she pulled strong, I went to shift to second under full throttle, my shifting was not as good as I thought it was, too slow I guess, the tach said it revved past 10k which I didnt think a big block Ford would do, and the clutch disintegrated. So now there is no down shifting and I am heading to the end of the strip and the brakes are not doing much good. I about bent the steering wheel pushing on them, finally slowing down enough to make the turn off the track. The whole clutch was contained in the bellhousing and was only a minor inconvenience to replace it.
    kidcampbell71 and loudbang like this.

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