flexplate certification

Is there any other reason to run an sfi flexplate besides certain class requirements? Does the stock one explode at some point? I have never seen one blow apart like a clutch so I am just wondering if I should spend the money now before the engine goes in instead of adding one later (a lot more work). It is just my 460 in a street car.

The welds on the outer ring, and the weight on the external balance ones have been know to be questionable, primarily the only ones I have ever had a problem with were BBC's (no mine) however if it meets the SFI safety requirement it should hold up to the class you are running it in even if it is an overpowered street car it is cheap insurance, a piece of metal at 7500+ RPM letting go at your feet is not cool.

jasonf wrote:Is there any other reason to run an sfi flexplate besides certain class requirements? Does the stock one explode at some point? I have never seen one blow apart like a clutch so I am just wondering if I should spend the money now before the engine goes in instead of adding one later (a lot more work). It is just my 460 in a street car.

Personal feeling is I'd be surprised to see a flexplate let go, but have seen a factory flywheel let go - blew the Lakewood BH right off the block

But then again, the SFI flexplates are pretty cheap, so why not do it now?

who was it posted he story about blowing up a stock one on the dyno a year or so ago??? Made a mess of the dyno cell... went out through the wall???

dkp

They are vid on youtube also i remember the guy forgot his and went the auto parts and pick up a factory flex plate to use on the dyno

Are you willing to take that chance with your feet ????

bosshoss wrote:who was it posted he story about blowing up a stock one on the dyno a year or so ago???  Made a mess of the dyno cell... went out through the wall???

dkp

This one?

http://www.460ford.com/forum/showthread.php?t=138991

Video of the event on youtube.

https://www.youtube.com/watch?v=vq5cjNhN_po

I have never seen an SFI one that out lasted a stocker and your money is better spent elsewhere.

the Question is how much do you like your Feet? I saw one slice the tunnel and dash out of a 65 mustang...

I have seen a number of stock flex plates break over the years, IMO the SFI spec stuff is worth the money. But it it's for a street ride I wouldn't worry about the cert being current.

jasonf wrote:Is there any other reason to run an sfi flexplate besides certain class requirements? Does the stock one explode at some point? I have never seen one blow apart like a clutch so I am just wondering if I should spend the money now before the engine goes in instead of adding one later (a lot more work). It is just my 460 in a street car.

It all depends upon how much you like your feet the way they are and whether or not you think they are worth that extra insurance.

A stock flexplate can certainly ruin your day.  





Not mine,.....
But a guy I know with a Supercharged 351w

A little JB weld and it's good as new

I have witnessed the damage done to a race car when the ring gear comes apart and exits the vehicle.
It was on my buddys 175 MPH Super Gas T bird with a 638. It had an SFI approved wheel.
Portions of the gear pierced the rocker panel and aluminum floor panels in the rear. It looked like a pissed off milling machine had been turned loose inside the UltraBell. I am not sure that it will recertify.
He was fortunate that none of the parts punctured a rear tire.
It seems like 1000 HP and more are the toughest on a flexplate. It begins with broken welds, and if they are not noticed, the ring gear will go "bye bye".
For a mild street build, a stock plate is fine.
4.5" or 4.75" stroke with ported aftermarket heads and big power, get the best wheel that you can afford and inspect the welds evey 25 runs or so.
I hope this info helps.
Keith

DaveMcLain wrote:I have never seen an SFI one that out lasted a stocker and your money is better spent elsewhere.

I agree,I don't know about the higher priced ones,but We put 2 SCAT sfi flywheels on Harold Websters car. They were breaking around the bolt pattern.The last time we went w/Stock Ford and as far as I know it still in car. The higher priced ones are probably ok.

I have had the ring break off of a couple of JW's in a dragster. Broke the case on one and bunged up the SFI bellhousing on the other. In fact I had to replace the bar under it.

I wouldn't run his, or a cheap one, but on a drag car, I would definitely run a good one.

I can't say with certainty, what works well and what doesn't work but, THE place around here which does a lot of High Horsepower transmissions of all brands will recommend nothing except a "Reactor Products" flexplate for anything.

Maybe he is a dealer or something like that however, I don't think that is his reasoning.

Here is a link to an old post of mine regarding this topic:

https://www.429-460.com/t10836-new-csr-flexplate?highlight=flexplate

I have been running this plate since this was posted in mid 2011. I sent it back last year for recertification and a routine gear replacement.
No issues....no problems.
I am sticking with this one.
The Reactor looks nice, but has welded plates on the ring that bolts to the wheel. It may be fine. I have no experience with it.
I know guys who swear by the Meziere FP308 one piece billet wheel. My only issues with that one is the non replaceable ring gear (a wear item) and the $425 price.
Just more input....
Thanks,
Keith Fulp

Wheelie58 wrote:Here is a link to an old post of mine regarding this topic:

https://www.429-460.com/t10836-new-csr-flexplate?highlight=flexplate

I have been running this plate since this was posted in mid 2011. I sent it back last year for recertification and a routine gear replacement.
No issues....no problems.
I am sticking with this one.
The Reactor looks nice, but has welded plates on the ring that bolts to the wheel. It may be fine. I have no experience with it.
I know guys who swear by the Meziere FP308 one piece billet wheel. My only issues with that one is the non replaceable ring gear (a wear item) and the $425 price.
Just more input....
Thanks,
Keith Fulp

Thanks Keith. I had read that post when I was researching flexplates yesterday. It looks like both of the CSR ones are internal balanced units and I need an external unit.

man I got an old used jw wheel that was expired when I bought it..... ive beat the shit outta that thing and its still holding up.

richter69 wrote:man I got an old used jw wheel that was expired when I bought it..... ive beat the shit outta that thing and its still holding up.

That was like the one that my buddy blew up. It was at least 8 years old.
Your light car helps...
I think that heavy boats are harder on flexplates.

PRW 1846010 is only $ 80.00 and SFI

I had a JW come apart at the finish line. What a mess.
A welder/metalurgist teacher at the local TAFE college look at it and said "they should not have tried to joined those two metals together"
There is no weld penertration in to the ring gear.
I now have a Meziere plate.

And here I was going to order a JW one. Now I don't know what to do.

I'd use a stock one. If it dont hold up you wont be surprised!