1966 428 flywheel

[mike01082]

Hi everyone, it has been a while but have started working on my Cobra and ran into a little problem.
Either my flywheel is too thing or the ARP flywheel bolts are too long.
Can I use a washer on the flywheel bolts?
Thanks,

[blykins]

No....

ARP clearly states in their packaging that you are to not use washers. In my opinion, it would take away the shoulder that's used on the bolt.

They make two different lengths, .750" and 1.000". Have you tried both?

[D-CEL]

The correct bolt length not withstanding, I would be cautious using a vintage flywheel in a high perf. application. If it fails, it will be very ugly.
If you are determined to use it, at the very least, have it NDT tested for cracks.

Jason

[blykins]

Good point J.....I got hung up on both length and didn't address that.

As cheap as billet steel flywheels are, it's a very safe measure to take.

[D-CEL]

Personally, I like Aluminum especially with the low weight of a Cobra. In my mind, there is no advantage having a heavy flywheel. Cobras want to break the tires loose anyway. The lighter flywheel will be softer coming out of the hole, wont shock the tires as hard and it will spin up faster.
If it was a 69 Torino with a small block on slicks, then hell yea. All that stored energy (40lbs wheel at 5k) can get a big tub moving, provided you can hook it up.
What is the cost difference?

Jason

[blykins]

It all depends on the clutch that he's using.

The 11.5/12" stuff basically requires either a McLeod steel flywheel or a McLeod/Fidanza aluminum flywheel.

The 11" stuff is all open for aftermarket flywheels and the price difference becomes about $125 difference. About $250 for a steel wheel, $375 for the Fidanza aluminum wheel.

I had an aluminum Fidanza in my Cobra after I had a 30 lb Hays and there was quite a bit of difference in how much I had to slip the clutch when taking off. That was the only thing I didn't care for.

[mike01082]

Thank you all, I have a new flywheel, steel. I will have to check the bolts that I got from ARP to see what the size was. Did not know that they made 2 size for the flywheel. Thanks again.

[Mark IV]

The bolts used on the Ford flywheel are called "place bolts" and have the shallow castellated heads. The head is slightly undercut on the mating side so when torqued the head goes very slightly concave to work as a locking system.

info here: Aetna - Place Bolts, Locking Place Bolts, Hex Head Locking Place Bolts, Six Slot Hex Head locking Place Bolts, GM Type AA Place Bolts, Slotted Bolts, Slotted Hex Head Place Bolts Grade8