Wrong Balancer??

[odin]

I recently bought a 68 Charger RT project. It has a 3698830-440-5 block dated 1-24-72 with a harmonic balancer and a notched flex plate. I’m in the process of replacing the 727 transmission. The converter in the transmission I’m removing was neutral balanced. The new transmission’s converter is also neutral balanced.

I noticed the notched flex plate and thought to myself, this engine must be externally balanced. I then looked at the balancer and noticed it has the offset weighted section on its face.

I researched the balancer online and believe it may be an incorrect application for this engine. The balancer has a small semi-circular notch cut into the edge of the weighted section of the face. 440 Source indicates the only balancer with that specific notch is 3614374 which they say only came on an externally balanced 400.

If this is true, why is it on this 440?
Should it work fine or will it cause problems?
What are your thoughts?

 

[440Coronet500]

That setup looks to be correct for an externally balanced engine. Do you know if that engine was built with a cast or forged crankshaft? 440'

 

[68HemiRR]

That's a 400ci cast crank balancer, not for a 440ci. A 440 cast crank balancer looks like this.

 

[pnora]

Time to pull the pan and see what crank and rods are in it.

 

[moparmarks]

72 440 should have a forged crank. 440 went to cast in mid 73.
Does the flex plate have a label on it?
I'd pull the pan too.
Did you drive it and if so did it have any vibration?

 

[odin]

That setup looks to be correct for an externally balanced engine. Do you know if that engine was built with a cast or forged crankshaft? 440'

I don’t know anything about the engine build. I’m slowly getting into the car and examining things. This was just the particular area that caught my attention yesterday

 

[odin]

That's a 400ci cast crank balancer, not for a 440ci. A 440 cast crank balancer looks like this.

View attachment 1527786

I would have thought that was the one in the engine if I hadn’t seen the small circular cutout and matched it to the 400 balancer on 440Source. I’m wondering how different they are and whether or not it is ok or something I need to address

 

[odin]

That setup looks to be correct for an externally balanced engine. Do you know if that engine was built with a cast or forged crankshaft? 440'

I do not know anything about the build including which crank it has

 

[odin]

72 440 should have a forged crank. 440 went to cast in mid 73.
Does the flex plate have a label on it?
I'd pull the pan too.
Did you drive it and if so did it have any vibration?

I didn’t take the flex plate off to see the other side so I’m not sure if it has a label.
I have not been able to drive the car because the transmission was bad. It would only move in reverse and first and was weak in both. Now that I pulled the transmission, I see writing indicating it was probably rebuilt in June 2022. It has no kickdown so I’m wondering if someone drove it too aggressively with no kickdown to regulate pressure in the transmission.

 

[R/T Boy 67]

I would run the engine and see if it vibrates. There are too many variables, to try and guess. It is possible that the engine builder knew what they were doing.

 

[moparmarks]

Hard to tell in your pic but that kind of looks like a 440-6 balancer. Might be a part number on it. Here is a 6-pack balancer.
70-72 440 HP motors used the heavy 6-pack rods with a forged crank and are externally balanced.
Non-HP motors used the lighter rods and are internally balanced.
Both used a different balancer.
A machinist could have balanced it using what is there.

 

[Runcharger]

If you didn't notice a vibration that's all you need to know I think. Yes, the previous transmission probably failed because of no KD linkage. Ascertaining the engine has a cast crank still won't guarantee all the components were balanced to work with each other. These projects are 50 years old so it's hard to know what parts were used. If it doesn't vibrate great, if it does then nothing but a complete teardown and engine balance will correct it.

 

[pnora]

Transmission might have a manual valve body. Thats why there is no kick down. That balancer clearly looks like the 400 cast crank balancer photo 440 source shows. It is not a six pack balancer. Getting the pulley off may show a part number.

 

[RemCharger]

I have 3 400 balancers, they're all identical with the notch.
So I punched in the 237 flexplate and sure enough, it's for cast crank ,383, 400, 440.
Which would make one inclined to think that all bb cast cranks have the same external weighting.

 

[Cranky]

I never experienced having the wrong balancer on an engine but did experience a neutral balance converter on an external balanced engine and that will let you know right now quick....

 

[odin]

I would run the engine and see if it vibrates. There are too many variables, to try and guess. It is possible that the engine builder knew what they were doing.

yeah, that is where I have ended up after talking to many "experts". The engine starts and runs fine now, but I can't tell how it is while driving and under a load until i get the new transmission installed. Fingers crossed it was a knowledgeable builder. I will come back and report my findings, but it will be a while

 

[odin]

Transmission might have a manual valve body. Thats why there is no kick down. That balancer clearly looks like the 400 cast crank balancer photo 440 source shows. It is not a six pack balancer. Getting the pulley off may show a part number.

that is exactly how I deduced it as a 400 balancer. I have not had a manual valve body in any of my previous transmissions so I was not aware of the fact they had no KD lever/cable. Is that on all manual valve bodies?

I am now installing a rebuilt 727 with normal forward valve body so I will need to buy a Lokar KD cable and bracket. The car already has a Lokar throttle cable on a Brawler bracket and carb.

 

[RemCharger]

yeah, that is where I have ended up after talking to many "experts". The engine starts and runs fine now, but I can't tell how it is while driving and under a load until i get the new transmission installed. Fingers crossed it was a knowledgeable builder. I will come back and report my findings, but it will be a while

I ran a cast crank with neutral balance stuff..
Bring it up to 1800 in neutral, you'll know if there's a problem.

 

[odin]

I have 3 400 balancers, they're all identical with the notch.
So I punched in the 237 flexplate and sure enough, it's for cast crank ,383, 400, 440.
Which would make one inclined to think that all bb cast cranks have the same external weighting.View attachment 1527891View attachment 1527892

that is one of the questions I could not find an answer to. If the 440 and 400 balancers had the same weight in the same area then they would be otherwise interchangeable (as long as I also matched the symmetric v offset bolt pattern). right??

 

[pnora]

that is exactly how I deduced it as a 400 balancer. I have not had a manual valve body in any of my previous transmissions so I was not aware of the fact they had no KD lever/cable. Is that on all manual valve bodies?

I am now installing a rebuilt 727 with normal forward valve body so I will need to buy a Lokar KD cable and bracket. The car already has a Lokar throttle cable on a Brawler bracket and carb.

All the manual ones with or without trans brake all looked like a stock valve body on the outside. Inside is a different story.