400 balance

[awohlers]

Hi Everyone,

I am completely new to engine building and this has been trial by fire. I bought a 70 Duster with a 400 (no trans) and have been recently acquiring all the parts to get it back on the road. I got an A-833 (Stock 4 speed car) and bell housing. I went to buy the clutch and flywheel today and the guy asked if the motor was internally or externally balanced. It was rebuilt about 8 years ago and hasn't ran since. Is there anyway to tell how it is balanced without pulling the crank out? I was reading I might just be able to pull the oil pan off, which I have to do anyways since the one they put it on it is leaking. The car came with the complete motor minus carb, distributor, alternator, starter, and water pump.

Thanks for the help!
-Adam

 

[EchoSixMike]

The harmonic damper in the front will have an offset weighted section on an externally balanced crank. The cast crank engines were supposedly all external balance.

Since it's been rebuilt, it could have been internally balanced then....if so, it's probably got some Mallory metal in it or the balance holes welded up, but that's pretty unlikely unless the guy was changing parts as well. S/F....Ken M

 

[awohlers]

The harmonic damper in the front will have an offset weighted section on an externally balanced crank. The cast crank engines were supposedly all external balance.

Since it's been rebuilt, it could have been internally balanced then....if so, it's probably got some Mallory metal in it or the balance holes welded up, but that's pretty unlikely unless the guy was changing parts as well. S/F....Ken M

There is no damper on it now. The guy didn't have a build sheet and said all her can recall is they put a mild cam in it. I'm guessing I should assume it is externally balanced and get the weighted fly wheel and damper?

 

[Plymouth 65]

Hi Everyone,

I am completely new to engine building and this has been trial by fire. I bought a 70 Duster with a 400 (no trans) and have been recently acquiring all the parts to get it back on the road. I got an A-833 (Stock 4 speed car) and bell housing. I went to buy the clutch and flywheel today and the guy asked if the motor was internally or externally balanced. It was rebuilt about 8 years ago and hasn't ran since. Is there anyway to tell how it is balanced without pulling the crank out? I was reading I might just be able to pull the oil pan off, which I have to do anyways since the one they put it on it is leaking. The car came with the complete motor minus carb, distributor, alternator, starter, and water pump.

Thanks for the help!
-Adam

Before you buy your clutch assembly and flywheel, pull the pan and see if it's a forged steel or cast iron crankshaft. Forged steel crankshafts were internally balanced. 65'

 

[SGBARRACUDA]

You may want to make sure your crank is drilled in the rear deep enough for the imput shaft of the trans. If it is a cast crank I doubt it is going to work with a 4 speed.

 

[awohlers]

You may want to make sure your crank is drilled in the rear deep enough for the imput shaft of the trans. If it is a cast crank I doubt it is going to work with a 4 speed.

I just did a bunch of reading. If I get the Dakota pilot bushing do I still need to cut the input shaft the 1/2-3/4 inch or does the new pilot bushing solve the problem of cutting the input shaft?

 

[bOb shingler]

no

 

[Sedanman]

If the motor isn't in the car you can drop the pan and look on the crank for added weights. IF it has them then it's most likely balanced

 

[SGBARRACUDA]

I just did a bunch of reading. If I get the Dakota pilot bushing do I still need to cut the input shaft the 1/2-3/4 inch or does the new pilot bushing solve the problem of cutting the input shaft?

No you will have to cut 4th gear imput shaft.

 

[GRANCUDA]

Here is how to balance the old flywheels for the 400 with its stock balancer from the old Direct Connection book.