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Failed flexplate..... #435587
08/12/09 02:10 PM
08/12/09 02:10 PM
Joined: Jun 2004
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zooom Offline OP
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Thought it worthwhile to post some pics of my son's failed "aftermarket" flexplate & associated damage to the race car. The starter ring disintegrated into several 2-3" pieces, and exited the ultrabell "scatter shield", during the 7600rpm, 1-2 shift in his ultraglide at about 90 mph.

Needless to say, this failure caused an immediate unbalanced condition with high driveline vibration so the run was aborted!

At the end of the track he was able to idle the car back to the trailer & we inspected the damage. Seems like the starter ring gear fractured at one or more of the welds & left the rotating flexplate tangentially. The inside of the aluminum ultrabell is pock-marked and torn(like a carbide burr would do when carelessly head porting!);a piece(s) exited thru the inspection cut out at the bottom and really gouged one of the bottom frame rails; another piece notched the top of the oil pan sump. Now the pan leaks when loading/unloading the car.

After further inspection we noticed that the starter nose gear/shaft is also broken & the oil pump pickup screen became detached from the tube - probably from the high vibration.

In retrospect the [NHRA-required] parts did what they were designed to do, i.e., protect the driver! On the other hand I think the weld quality of some of the aftermarket stuff is questionable......

Re: Failed flexplate..... [Re: zooom] #435588
08/13/09 02:03 PM
08/13/09 02:03 PM
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Posts: 388
Michigan
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SD800 Offline
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I hope it wasn't a JW wheel, I just ordered two of them.


You'll have plenty of time to sleep when your dead, let's go
Re: Failed flexplate..... [Re: zooom] #435589
08/13/09 02:14 PM
08/13/09 02:14 PM
Joined: Jun 2003
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Romeo MI
MR_P_BODY Offline
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Romeo MI
It looks like its brittle from the weld(too hot)

Re: Failed flexplate..... [Re: SD800] #435590
08/13/09 04:10 PM
08/13/09 04:10 PM
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zooom Offline OP
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Wasn't going to name names, but yes, it was a JW "wheel". It has been in service for ~5 years & has seen ~250 runs behind my hi-comp, hi-winding, W2 headed, R3 block, 416 stroker.

JW says something to the effect that if you run too much compression & the starter kicks back often, the flywheel could be compromised.

BULL [Edited by Moparts - Family Friendly Site - Keep it clean]!

I say: "Just weld/heat treat it better; and considering the price charged, it should be fool[fail?]proof!" Who knows though, these things may come from China/Taiwan/Korea/etc. too....

5415450-framedamage#2.JPG (139 downloads)
Re: Failed flexplate..... [Re: zooom] #435591
08/13/09 09:32 PM
08/13/09 09:32 PM
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Arizona
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Chris'sBarracuda Offline
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Try one of these....

Olan @ Reactor..

http://www.reactorproducts.com/mainProducts.html


Chris..

Re: Failed flexplate..... [Re: Chris'sBarracuda] #435592
08/13/09 10:33 PM
08/13/09 10:33 PM
Joined: Jun 2005
Posts: 6,257
gulfport, ms, west mi
rowin4 Offline
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A couple of years ago I was at mobile dragway when a flex plate came apart like that , sent a chunk of the ring gear into the stands hitting a girl in the arm . I seem the sparks from under the car them the scream. Not a good situation. Didn't Fred's come apart also?



it's ok to butt heads, just don't do it with a butthead
Re: Failed flexplate..... [Re: zooom] #435593
08/14/09 12:55 AM
08/14/09 12:55 AM
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Posts: 296
Ontario Canada
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Hutch Offline
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Ontario Canada
We had a few also years ago and blamed the welds on several different flexplates. We sawed off the headers complete and went through the right side torsion bar in one explosion. I went on to build a completely welded one and it failed also.

After furthur studying the breakage I noticed that it originated closest to the converter pad where the converter was flexing the flexplate forward excessively.
Do a check on the thrust bearing in the motor for damage and check the cooler pressure to see what it is.

Hutch

Re: Failed flexplate..... [Re: Hutch] #435594
08/14/09 08:21 AM
08/14/09 08:21 AM
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Posts: 388
Michigan
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SD800 Offline
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I thought I read some where the Wheel became SFI certified a year or so ago. did yours have the SFI sticker on it? I just recieved both my wheels yesterday and they have the SFI sticker on them.

I'll be sure to change them in three years and send them to the scrap man so no one can but them on thier car and hurt some one


You'll have plenty of time to sleep when your dead, let's go
Re: Failed flexplate..... [Re: zooom] #435595
08/14/09 10:53 AM
08/14/09 10:53 AM
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Posts: 16,916
NC
440Jim Offline
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Quote:

Wasn't going to name names, but yes, it was a JW "wheel". It has been in service for ~5 years


Sorry to hear about the damage. I agree that is disappointing. A racing flexplate should be inspected at least every 3 years. The NHRA/IHRA safety rules require SFI 29.1 flexplates (9.99 or 135 mph) that expire 3 years after date of manufacture.


1993 Daytona, 5.50 at 130mph (1/8) 1.19 sixty ft (PG). Link to 572 B1 - Part 1
Re: Failed flexplate..... [Re: 440Jim] #435596
08/14/09 03:53 PM
08/14/09 03:53 PM
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Posts: 1,131
Thigh-Gap Junction
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@#$%&*! Offline
New user name, Same old jerk!
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I wish they'd restrict that rule to flexplates with ring gears attached to them. It's the ring gear that comes apart when attached to a flex plate. I'm not saying Chrysler type flexplates don't fail, just never seen one that flew apart like the two-piece ones.



Quote:

The NHRA/IHRA safety rules require SFI 29.1 flexplates (9.99 or 135 mph) that expire 3 years after date of manufacture.



Re: Failed flexplate..... [Re: @#$%&*!] #435597
08/14/09 06:58 PM
08/14/09 06:58 PM
Joined: Sep 2006
Posts: 4,628
Columbus, Ohio
wheelsup68dart Offline
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Dad has been thru 2 in his ride in the last 3 years, both JW pieces. 1 of them went thru the bottom corner of the oil pan.

Re: Failed flexplate..... [Re: zooom] #435598
08/14/09 07:20 PM
08/14/09 07:20 PM
Joined: Feb 2004
Posts: 1,417
Chicago, IL
blownEFI Offline
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Chicago, IL
Perhaps a billet one-piece flexplate is the way to go. No welds to fail.


"These go to eleven", Nigel Tufnel
Re: Failed flexplate..... [Re: wheelsup68dart] #435599
08/14/09 07:21 PM
08/14/09 07:21 PM
Joined: Jan 2007
Posts: 3,695
nc
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emarine01 Offline
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We broke a mopar perf flex plate in our 414 , just went into the chip and made a nice spark show @ night, why are you guys runing the ring gear on the flex plate and not on the verter, I would think the ring gear wont take too much flex?

Re: Failed flexplate..... [Re: emarine01] #435600
08/14/09 08:12 PM
08/14/09 08:12 PM
Joined: Jan 2003
Posts: 5,892
Florida
Locomotion Offline
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Florida
Quote:

We broke a mopar perf flex plate in our 414 , just went into the chip and made a nice spark show @ night, why are you guys runing the ring gear on the flex plate and not on the verter, I would think the ring gear wont take too much flex?




Usually for Powerglide/other GM trans. that were adapted.

Re: Failed flexplate..... [Re: Locomotion] #435601
08/14/09 08:57 PM
08/14/09 08:57 PM
Joined: Jan 2007
Posts: 3,695
nc
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emarine01 Offline
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nc







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