Harmonic Balancer Blues!!!

[Longknife]

First question,,,, I have a 2468130 block (383) with 5-25-71 build date. stock bore, mildly built. Four speed. I always seemed to have a vibration in it. My thoughts came to light yesterday when the Harmonic balance came apart and began rubbing against the timing cover. I removed the balancer and it is a cast crank balancer. I also discovered that my engine has a cast crank,,, I actually scoped up through the drain plug to verify this. More research indicated that Mopar did put cast cranks in 2 barrel 383s' in 71-72. The part number for the balancer is 3577180. A two year only item. The 400 cast cranks used a different number. I have not had much luck in finding one on the net....

Second Question, This 383 two barrel engine was undoubtedly first equipped with an automatic trans. I now have a four speed behind it. Would the flywheel have to be balanced with the engine? Did the flywheel out of balance cause the balancer to come apart? I know For a fact that the balance was OK when I got the engine. The cast number on the f-wheel is 8015,,,,, Thanks, Ed

 

[Don Frelier]

Sounds like the balancer has been bad for a while.
Put a new balancer on it and see how it acts then go from there.

 

[Charger Dana]

Someone would probably give you a forged crank. Certainly not expensive. But more expensive than a balancer.

 

[IQ52]

The cast crank 383's and 400's use the same flywheel and torque converter offset balance. This leads me to believe that the 383 and 400 damper should interchange (though I have not been able to verify this). The flywheel must be balance to the cast crank 383. Below is how the old Direct Connection book shows how to balance a flywheel for the 383, 400 & 440 cast crank engines The same flywheel offset is used for all three engines. The drawing is showing the engine side of the flywheel.

 

[69Bee]

1) Use a neutral balancer and flywheel and re-balance the engine
2) Balance the flywheel (per above), then look forever for the correct balancer. (Damper Doctor in CommieFornia can rebuild it for you)
3) Get a steel crank, neutral balancer and flywheel, and still balance the rotating assy.

 

[Plybeep68]

http://store.440source.com/Internal-_-External-Balance-Black-Damper/productinfo/200-1128/

 

[69Bee]

http://store.440source.com/Internal-_-External-Balance-Black-Damper/productinfo/200-1128/

For a 440 steel & cast, but not for 383/400 cranks

 

[Plybeep68]

What about this one
https://www.cnc-motorsports.com/sca8013-scat-harmonic-balancer-chrysler-383-400-413-426-440.html

 

[69Bee]

What about this one
https://www.cnc-motorsports.com/sca8013-scat-harmonic-balancer-chrysler-383-400-413-426-440.html

Maybe, as it does cover the 400, and a cast 383 might be the same.

 

[Longknife]

Thanks guys, Here is what I "think"? The HB for the 71-72 cast cranks 383's had the one offset pulley bolt hole. In 73 when the 400's came out the holes were then drilled equal and a new part number was required.???? SOOOO same balancer on either cast crank engine,,,,,
I can not see the three drilled balance spots in the flywheel, so I'm betting that is my problem. I need to remove my flywheel and drill those spots. ORRR get the correct flywheel, Brewers offers the flywheel neutral or balanced (drilled)

Brewer's Performance - Mopar A833 4-Speed Transmission and Component Specialists

 

[66Satellite47]

The other thing to consider, if you haven't already, is the pilot hole in the crank. There are other threads here that discuss the pilot issue.

 

[Longknife]

The other thing to consider, if you haven't already, is the pilot hole in the crank. There are other threads here that discuss the pilot issue.

Yeah I have thought about that too. The moron who cobbled this engine together did something to get the 4 speed in, I will not know what he did till I get the trans out and take a look!!!,,,Ed