BB Flywheels Question

[chaos52]

Can anyone tell me what these flywheels are? I've done some searching and haven't been able to positively ID either one. I know that they both definitely fit a big block. I think the one with numbers might be for a 383 and the one without numbers might be for a 400. I need one for a 400.
Thanks in advance!

[Chryco Psycho]

the one with the #s & drill holes in the rear is dfinatly for a external balanced engine , I do not have my Mopar engine book handy or I would look up the drill pattern to identify it . The bolt pattern is the same for all V8 engines except the Hemi so it could fit 340, 360, 383 cast crank , 400, 440 cast crank or 440+6 as all were external balanced

[chaos52]

the one with the #s & drill holes in the rear is dfinatly for a external balanced engine , I do not have my Mopar engine book handy or I would look up the drill pattern to identify it . The bolt pattern is the same for all V8 engines except the Hemi so it could fit 340, 360, 383 cast crank , 400, 440 cast crank or 440+6 as all were external balanced

Ok, I wasn't aware that the bolt patterns were the same. I wondered if that flywheel was for an externally balanced engine, but I thought it was from a '69 383 Road Runner, which I assume would be internally balanced, so I was confused.

Anyway, is there a place I get hold of an engine book? Or could you look that up and let me know?

Thanks

[Chryco Psycho]

My book is approx 5000 miles from me right now but someone here will have the illustrations you need .
The engine book is available from Mancini racing , good to have 

[heyoldguy]

If those three balancing holes are 31/32" in diameter and .66" deep the flywheel is for a cast crank 383/400/440.

If they are 1-13/64" in diameter and .66" deep, the flywheel will be for a 360

The flywheel on the right appears to be one for an internally balanced engine and can be used on any forged crank engine other than the 440 6-pack which will have  two .368" diameter holes drilled all the way through 14 degrees apart and 5.735" from the very center of the flywheel.

[Ghoste]

Does the casting number give any useful info to identify?

[chaos52]

Does the casting number give any useful info to identify?

No, unfortunately. I tried looking up the numbers online, but there was no definitive information.

If those three balancing holes are 31/32" in diameter and .66" deep the flywheel is for a cast crank 383/400/440.

If they are 1-13/64" in diameter and .66" deep, the flywheel will be for a 360

The flywheel on the right appears to be one for an internally balanced engine and can be used on any forged crank engine other than the 440 6-pack which will have  two .368" diameter holes drilled all the way through 14 degrees apart and 5.735" from the very center of the flywheel.

Thanks, I'll measure and see what I've got...

[John_Kunkel]

That 2843212 casting number is a 143 tooth flywheel used with the 11" clutch.

[Rolling_Thunder]

If that is a flywheel for an external balance 440 that is one RARE and hard to find piece. 

[chaos52]

Looks like the external balanced one is for a 360.

So, I still have to find a flywheel for a 400...unless I stroke it...

Regardless, thank you all for the help.

[Chryco Psycho]

or add weight to the crank & internally balance it

[heyoldguy]

Looks like the external balanced one is for a 360.

So, I still have to find a flywheel for a 400...unless I stroke it...

Regardless, thank you all for the help.

The flywheel on the right can be balanced for the 400. Any good machine shop can handle the task.

[chaos52]

or add weight to the crank & internally balance it

The 400 I have is NOS and freshly rebuilt, so I don't want to tear it apart just yet. That comment was more of a joke than anything, although I do plan to stroke it someday.

The flywheel on the right can be balanced for the 400. Any good machine shop can handle the task.

I've read about that. But, is it possible to do it without pulling the crank and balancing the entire rotating assembly? Really though, I'd prefer not to ruin that flywheel with my future plans.

[Cooter]

No Cast crank 400's came with a straight gear to my knowledge, as all the factory did was swap out the cast crank for the steel 383 piece and balanced internally.

[heyoldguy]

Well you can do this several ways. First, they don't have to balance it with the rotating assembly.

Second, they can just put the "400" balance on it because there are specific diameter, location and depth of holes for the 400.

Third, you can if you so desire rebalance it for an internally balanced engine.

Fourth, you can have the 360 flywheel balanced for the 400 engine and save the other flywheel.

Can this really be done? Yep, have done it for all of these options

[chaos52]

hmm, yeah if I can rebalance that 360 flywheel for a 400, that'll be the way to go. Now I just need to find a machine shop that will do it... Thanks for the help! 

[John_Kunkel]

The 360 has the largest external balance of any Mopar V8. Even if it could be rebalanced the factory flywheel is a grenade...go billet.

[chaos52]

We'll have to see what the bank account says next summer...I'm on a pretty tight budget and I'm assuming a rebalance is going to be a considerable bit cheaper than going new. But, is a '78 400 with a mild cam really going to put out enough power to blow up a flywheel?

[John_Kunkel]

You don't need power, just rpm...cast flywheels explode from centrifugal force and the larger the flywheel the more centrifugal force.