flexplate certification

You could use also use a SFI flexplate shield, at least if the flexplate lets go you have shrapnel protection?.

The problem I see with these aftermarket and supposedly better flexplates is that they are made incorrectly for the job. What they do is make them from the same mild steel material but thicker and this is not a good solution because their job is to allow for some minor misalignment between the engine and the transmission they are a "flex" plate. When they are thicker they can't flex and instead they crack. What should be done is to keep them about the same thickness as a stocker but make them from a superior material.

FalconEh wrote:You could use also use a SFI flexplate shield, at least if the flexplate lets go you have shrapnel protection?.

This thread has convinced me to buy a shield for my "soon to be" 499, 4200lb Galaxie C6. I have a SFI cert flex plate, but Dave McLain's comment about the thicker but lower quality material/poor workmanship, made me a believer
Hughes, $115 at Jegs.

With the shield at least feet stay unpenatrated.  Bummer is when the explode catastrophicly the ruin trans and sometimes block.

I have a PRW SFI rated plate in my car, it's quite a bit thicker than a stock plate and it's solid - no holes other than the coverter bolt holes.

Whats the combination?
Id use an oem plate in a mild street/strip application wo hesitation. Higher hp race only stuff an sfi rated plate is a no brainer imo. I have the CSR plate on mine and have no complaints.

BigRigTech wrote:I have a PRW SFI rated plate in my car, it's quite a bit thicker than a stock plate and it's solid - no holes other than the coverter bolt holes.

The one I have is the same way. It's a C.A.T. ?!!

I got a old cat the same way its almost out of cert its been a good one.

gmsmkr wrote:I got a old cat the same way its almost out of cert its been a good one.

That's nice to know

I had a cat on the 460 turned it 6500 rpm and never had a problem from it you can get it external or internal balanced mine was external when I built the 552 it internal and I bought a CSR for it. The CSR is/or looks to be a lot better built over the cat and carries both converter bolt patterns ford and chevy. That is the only 2 have bought and compared side by side, the cat is about 1/4 of the price I paid for my CSR and for a mild build I buy another cat if I needed it to have a cert.

I found one for my external balance build it will be spun in the 7k area. I was spinning the other around 6500 also it was internal.

dirt_worker wrote:Whats the combination?
Id use an oem plate in a mild street/strip application wo hesitation. Higher hp race only stuff an sfi rated plate is a no brainer imo. I have the CSR plate on mine and have no complaints.

It's a 466 with ported TFS 290 heads, street solid roller, TFS intake, Lentech AOD. It is going in my 56 Mainline and is a street car. I've been collecting parts for a couple years now and I am just grabbing the last few items so I can actually get this project moving ahead.

the prw 1846010 is a dual pattern fp for ford and gm both 10.75 and 11.5 and is SFI. Have been looking at the PA flexplate and they are a prw and sale at summit for $140 while the same plate in prw is $80

Flex plates are "flexed" not just by misalignment, but also by converter thrust. limit the converter thrust (max travel) to less than .025 or so and most of them won't break. put a bunch of washers under the converter mounting pads, install a high pressure spring in the pressure regulator, restrict the cooler return, and camp on the t-brake and most of them will break no matter who made them. add a mid plate adapter and no thrust braces and its a time bomb.

Copperhead wrote:A stock flexplate can certainly ruin your day.  





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

I know for a fact a cracked flex plate sounds like a rod knocking also....

To the guys that broke JW's, was that the "wheel" flexplate?

I was told that they were pretty good.

Beast wrote:To the guys that broke JW's, was that the "wheel" flexplate?

I was told that they were pretty good.

Yes...The Wheel is what they call their flexplate.
They are very good in most applications. I had no issues with that part with my 514 for years.
It is when the 605 was installed that I started having issues.
Normal drag cars weigh 1800 to 3000 lbs. mine weighs between 3700 and 4000 depending on the class.
JW is a great family owned company and they make very good, innovative parts.
Other plates with welded ring gears do the same thing.

Copperhead wrote:A stock flexplate can certainly ruin your day.  





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

When my buddy ran the gas station we would get some pretty good deals on cars with flex plates that looked like that. They'd come in all rattely and blown up sounding and he'd buy them for scrap