Flywheel Help!

[70DusterDev]

So I have a late 72 340 with a CAST crank and am converting it to a 4spd. From the people I have talked to it is almost impossible to find a factory 340 externally balanced flywheel just because they only made em for about a little over a year and Brewers wants $230 for one and money is tight. Is it possible to take a neutrally balanced flywheel and have it drilled to the factory specs of the externally balanced wheel? One more piece to add is that the motor is in the car so I wouldn't be able to bring the crank with the flywheel. I have seen a picture that cracked back has posted a few times. Is this 1 hole all it is for the externally balanced flywheel in that exact spot?

Thanks :cheers:

 

[deep]

never heard of this before, had a 70 340 with cast crank, and it was balanced on the inside, 340 4 speed 70 cuda'

 

[yellowdartdave]

Deep,

1970 had a steel crank, unless somebody swapped either the entire engine or the crank, balancer and other stuff from a 72 1/2 or 73 340.

 

[684mulas]

I have one (pictured on 72 cast crank 340) I would sell. PM me if interested.

 

[684mulas]

Difference can be seen here. 340 cast flywheel on right.

 

[684mulas]

Here is the bellhousing (and the close up of the crack) that you asked about. I'm not sure if I still have the clutch fork but if you want any of it, let me know and I will dig deeper.

 

[340duster]

So I have a late 72 340 with a CAST crank and am converting it to a 4spd. From the people I have talked to it is almost impossible to find a factory 340 externally balanced flywheel just because they only made em for about a little over a year and Brewers wants $230 for one and money is tight. Is it possible to take a neutrally balanced flywheel and have it drilled to the factory specs of the externally balanced wheel? One more piece to add is that the motor is in the car so I wouldn't be able to bring the crank with the flywheel. I have seen a picture that cracked back has posted a few times. Is this 1 hole all it is for the externally balanced flywheel in that exact spot?

Thanks :cheers:

I haven't done this with a 340 cast crank and flywheel, but I did do it with a 360 (it required more to be removed) and it worked fine. I also worked out the imbalance on a 360 magnum and did the same on a flywheel and it worked fine. So go for it!

 

[1wild&crazyguy]

you need to know the counter balance weight, typically you do this with the crank and bob weights to simulate the rotating mass=pistons/rods/rings/clips etc...

 

[340duster]

you need to know the counter balance weight, typically you do this with the crank and bob weights to simulate the rotating mass=pistons/rods/rings/clips etc...

70DusterDev is trying to make a 340 cast crank flywheel, not rebalance his rotating assembly

 

[1wild&crazyguy]

no sht genius.....notice I said typically???

gee is it a frukin crime to enlighten people to the standard process?

tell me how you would balance the flywheel for this?
btw...360 magnum balance is not the same as pre magnum 360 balance.

I consider whats been already posted as good info and only adding to it, hell it gives the guy an idea of what has to overcome.

So if you get what I'm saying, cool... we now understand each other.

if not, ooooooooooowell

 

[340duster]

no sht genius.....notice I said typically???

gee is it a frukin crime to enlighten people to the standard process?

tell me how you would balance the flywheel for this?
btw...360 magnum balance is not the same as pre magnum 360 balance.

I consider whats been already posted as good info and only adding to it, hell it gives the guy an idea of what has to overcome.

So if you get what I'm saying, cool... we now understand each other.

if not, ooooooooooowell

I am not trying to start an argument, but I didn't want 70DusterDev to think he needed to rebalance his rotating assembly. He can simply modify his neutral balance flywheel to work with his exernally balanced cast crank 340 engine. The same can be applied to a 360 LA or 360 magnum just the amount of weight is different for each engine.

 

[70DusterDev]

Alright thanks! Yes Wild, a buddy told me the same thing but he was unaware if you could balance the flywheel without the crank. From what I have read as long as you have the blueprints which I have above you can do it. And thanks 340! 684 said he does have one in those pictures that is for an externally balanced crank but it has other holes as well. I've got a buddy with a machine shop looking through his pile to find a neutrally balanced one but if not I'll probably try it out and if its wrong and I get a vibration I'll find a neutrally balanced one and start over.