Looking for new 143 tooth flywheel, is a SFI approved a must?

[KillerBee]

Getting clutch parts ready for the new 440 Six Pack engine going into my 71 R/T Challenger.

I currently have 2 used 143 tooth flywheels that I'm going to have inspected.

If they don't pass I plan to buy a new on.

In looking at flywheels it appears the new SFI approved ones are more than twice the price of the new non SFI ones.

Engine is approximately 500 horse going through a Hemi 4 speed to a 3.73 equipped Dana 60.

Car will be 90% street driven on radial tires with a occasional trip to the drag strip with ET street tires.

Is the SFI flywheel a must for my application?

Thanks.

[jhaag]

required..no, however if you try to run your car at an NHRA sanctioned drag strip and it runs under a certain ET, you may have to have 1. check the rule book available on line. If you need an SFI flywheel, you will also need an SFI approved scattershield and harmonic balancer. How fast do you intend to go? how safe do you want to be?

[Chryco Psycho]

If you are not using a blastsheild it is nto a bad idea to have a flywheel of the best quality available .
 my clutch & flywheel cost $1300 , McLeod twin disc

[KillerBee]

Will probably only take it to my local independent 1/8 mile dragstrip on rare occasions.

I've run my street/strip 1973 Challenger there on occasion and never had anyone in tech ever ask about the flywheel.

How would tech determine the flywheel is SFI?

I've had/used these flywheels for quite awhile, I thought one of them was SFI rated, is there anyway to determine that?

[Chryco Psycho]

usually the sicker is applied to the engine side of the flywheel , easy to see if the inspection cover is dropped , or you can keep the sticker in the car which will prove you bought a  sfi flywheel even if it is not the one inside the car

[KillerBee]

usually the sicker is applied to the engine side of the flywheel , easy to see if the inspection cover is dropped , or you can keep the sticker in the car which will prove you bought a  sfi flywheel even if it is not the one inside the car

Neither of my current flywheels have stickers.

I thought one had a stamping on it, I'll have to check.

I don't imagine the stock 143 tooth flywheels were SFI approved, I'll see how they check out.

[73restomod]

When I was a young teenager I watched my father's drag car loose a flywheel in-front of our garage when he was free revving it. He had no SFI bell or scatter-shield. It buried it into the concrete a good 13 inches, he's lucky it didn't go up, or else he probably wouldn't have a foot. I wouldn't recommend skimping on the flywheel, especially a 143 tooth flywheel that weighs more, and generates considerably more inertial load than a 130 tooth.

[Chryco Psycho]

I have witness a couple as well , in one case I watched a drum from a 727 trans clear the stands at a dragstrip & land in the pits , I have also seen the result of upward explosions floorpan ,dash windshield etc did nothing to slow the exit of a flywheel , feet have been lost , Don Garlitz is missing a good portion of one of his feet in a front engine dragster incident which is why the mid / rear engine was designed by him

[bigblue73]

First off - Are you sure that your car is using a 143 tooth flywheel.  The Mopar Big Blocks used both 130 and 143.  I'm not sure of the cut-off.  Most SFI rated bell housing (Lakewood and Quick Time) are going to use the 130 tooth flywheel.  Use the 10.95 clutch from your favorite vendor and you have it.  The McLeod RST Clutch is an excellent choice by the way.