Technical Early Chrysler Hemi Crank Balancer question:

Hey all Hemi Experts out there. I’ve got a question reguarding my 58 392 Chrysler. I got it some years back. It was built up, then shoved under a shop work bench where it sat for many years till the old man passed, a friend bought the contents of the shop and sold the Hemi to me. Outside it looked like an engine that sat indoors for a long time, but inside it was clean. Pulled the pan to give the bottom a look and spied Venola pistons, all internals were clean and spun easily with the plugs
Question: it came with a small 5” diameter harmonic balancer. Weighing about 2lbs. No timing marks or casting numbers. Later I score a larger 7-1/4” diameter 5 lbs H.B. With casting numbers and timing marks. Are they both okay to run? I’d rather run the chrome one cuz.....hehe

 

I might be wrong,,,but the small one looks like a drive hub ?
Maybe for a blower drive ?
It looks like the center register is a larger size then a factory pulley .

Tommy

 

Hi Tommy, you’re right in that the wall of the pulley register looks thicker, but I just put a micrometer on them, they match. Which would then suggest the I.D, is smaller.... gimme a sec. Nope I.D. Is the same too

 

If it came with the smaller damper it probably was balanced with the smaller one. In which case I would run the smaller one.

 

The bigger one looks a whole lot like an actual damper, with a hub, rubber ring, and an outer ring.

The smaller one looks a whole lot like just the center of the larger one.

128668 is the part number for a Chrysler damper: 66-91 318, 340 (S/C) 3.9 LT. V-6 #A128668

Some outfits, like Hot Heads, and others, convert 340 dampers for use with first-generation Hemis.

 

I would be hesitant to run the smaller one for anything but a DIY blower pulley hub, as it has no inertia ring.

 

There is a historical pathway as to why this bolt hole pattern, pitch-circle-diameter, and hole register appears on common blower pulleys.

I would wager the register on both is 2-1/4".

 

I'm pretty sure the smaller one is just the inner hub of the bigger one with the rubber and outer rim removed.

 

Thanks guys. I’ll use the bigger chrome one. Seeing as how I’m going to test fire it on an engine stand and see how everything goes.