Flywheel for FE with 428 crank

[MOTORHEAD]

I'm wondering if I should replace my stock cast flywheel with something else
My engine was built by person/s unknown in 1998 with Shelby alum 427 block and a stock cast 428 crank for a cheap stroke increase. Unlike the rest of the FE's the 428 crank must be balanced with the flywheel, so changing the f/w means tearing down the bottom end. I'm fine with the crank, but have no info on the f/w (C6AE 6380B ) as to its durability. The engine is rather mild, with 9.5 : 1 compression, E-brock heads w/ big valves (but not ported) and cam has not been decided upon as Im switching to a weber set-up. HP approx 450-500.
I also have an aluminum f/w for a FE that is NOS, has been balanced with some crank (not mine) but never installed. Has never been drilled for clutch, and has no steel clutch facing, but can be set up with some machining and a steel clutch surface (or not).
Looking for some input as to which way to go.
TIA
Ted

[Jerry Clayton]

You can take the flywheel you have and check the balance of it---if it is neutral then its easy to do the replacement

If it is external, add weights to it in 2 places (bolts&washers) til it comes into balance, index those weights to the new wheel, (line up crank bolt pattern) and balance assy, remove the weights and you will be balanced to your engine

If your machinist doesn't understand---find a different balance shop

[blykins]

Don't use an old cast iron flywheel. Too many instances of them coming apart at rpms. Very unsafe.

Flywheels are pretty inexpensive for the FE. I offer brand new billet steel pieces for $225. New aluminum ones start at $385.

For such a large amount of money spent on an engine, it's worth the insurance to spend an extra couple hundred bucks for a nice flywheel that you don't have to worry about.

For future reference, if you have a flywheel that you would like to use and it's not matched to the rest of the rotating assembly, you don't have to tear the engine down to use it. Most machine/balance shops can balance a flywheel by itself. So if you have a neutral balance wheel and you'd like to use it on a 428, then the shop can balance it and stick a 28oz weight on it. Conversely, if you have a 428 flywheel and you want it 0 balanced, they can remove the weight and neutral balance it. It's just a matter of balancing one flywheel against another known flywheel.

Your aluminum flywheel would probably work just fine, but you'll spend more money on having it machined and fitted with the friction plate and having it drilled than you would on buying a brand new one.

[Jerry Clayton]

Brent

I find it necessary to disregard the idea of just putting a 28 oz weight on because it isn't ever known if thats what the engine had ---yes the new aluminum wheels all have the weight in the same place but thats no guarantee that the engine is or is not 28 oz.

So I always willdo the weight thing and then if a 28oz will balance it correctly will use it but history usually lifts its ugly head and it will be more or less---however the spot is usually correct---I have a pile of them that have been lightened or welded on

[blykins]

Jerry, I was just using that as an example, but you bring up some good points.

I took it that the flywheel that's on the engine now is correctly balanced to the rest of the rotating assembly. If so, then he can take that flywheel and a new one and have them weight matched.

[MOTORHEAD]

Jerry and Brent: Thanks for the input! The present cast wheel has been balanced to the crank when the eng was built, and again when I re-built it. I talked to the shop that last did it, and they said they didn't make any changes to the balance. They also said that in their experience (30+ yrs), that trying to match balance to another wheel would be close , but not good enough. Checked with another mach shop (oldest in Sarasota, hot rodders from the 50's) and they basically said the same thing. I have a couple more shops to check, but if I have to pull the crank, I'll do it, rather than risk it not being right. The engine is not done, it's on the stand, and I may be pulling heads for port matching. My main concern was if the stock wheel was up to the task or not.
Brent: are the aluminum f/w friction plates available as a replacement part? My clutch is approx 11.75" dia. .
Thanks,
Ted

[Jerry Clayton]

Ted

I do these all the time----The balance can be matched exactly---within 1 gram ---the only question is how close was the original job???

I would suggest that you get a new flywheel compared to trying to put heat shield on yours---those alum wheels around without heat shields/clutch bolt patterns were typical for a boat---you being from Florida----

[MOTORHEAD]

OK, looks like I need a new f/w. But it will still need to be balanced to my old wheel or crank, right?

[Jerry Clayton]

right
since your engine is still on the stand--if you have the piston rod weights, rebalance the crank and flywheel

[MOTORHEAD]

Thanks Jerry ! I assume you mean piston and rod weights, which I do have. Now I just need to find a f/w !

[blykins]

Ted,

The only replacement friction plates I can get would be for a McLeod, RAM, or Fidanza flywheel. The Fidanza aluminum wheels that I sell have multiple pressure plate patterns on them....11", 11.5", and 12". Your 11.75" is either an 11.5" or a 12".

I have seen a few engines where instead of whacking a counterweight off, the flywheel was made with a particular imbalance. However, that's not the right way of doing things.

FE crankshafts are either internally balanced (390 and 427) or externally balanced (428). The entire rotating assembly was balanced with a 428 flywheel, so just put another 428 flywheel on it.

I would not disassemble a complete engine just to change flywheels. I hope that you don't plan on doing that.

Bottom line is you have 3 options: 1. Reuse the cast iron flywheel. 2. Use the aluminum flywheel. In that case, I'd have it weight checked against the iron 428 flywheel. 3. Buy a new flywheel, with a 28oz imbalance.

When you balance a rotating assembly, you don't alter the flywheel to match the rotating assembly (unless like I said above, where the case is totally original and hacked up). You remove/add weight to the crankshaft depending on the bobweight and the balancer/flywheel that you use. You use either a 0 balance flywheel or a 28oz flywheel.

Again, please don't take apart a good engine just to have it rebalanced with another flywheel.

[MOTORHEAD]

Brent: OK,my brain f2rt, pressure plate and disk both measure exactly 11&7/8" not 11.75".
That would be the 12" pattern ? Why the discrepancy ?
What would be the prices for steel and aluminum flywheel for the 428 crank , no shipping ? You can PM me or call @ 941-730-2020.
Thanks,
Ted

[blykins]

11-7/8" is pretty close to 12".

If you plan to use that pressure plate, the less expensive steel wheels won't work. They only feature 11" Long patterns.

For the 11.5"/12" pattern, you have to go with either a McLeod or Fidanza flywheel. They both have those patterns.

Both are SFI rated.

The McLeod wheel weighs 40lbs.

The Fidanza wheel weighs 14lbs.

The McLeod is $389 + shipping.

The Fidanza is $385 + shipping.