If you started with a 400 small block, you do know that it was externally balanced don’t you?

The flywheel and harmonic balancer were unique to this engine and both carried a counter weight that the other small blocks do not.

Good luck… GUSTO

 

I started with a 400 block.block only had it balanced internal.

 

Harmonic balancer failed--key sheared off due to other issues. It was a MESS and thought it was not salvageable.

Sent it to DAMPER DOCTOR in CA. (https://damperdoctor.com/)

He completely repaired mine for $110.00 ('66 327/300) and it looks amazing.

Strongly recommend him for any of your needs in this area; from his website you can see he has many in stock if yours is not salvageable.

Cheers,

Richard

 

Thank you, just sent them a quote request.

 

Not to be **** here but, the use of the term "Harmonic Balancer" is at best a poor a choice of words, but really is inappropriate, as the subject is actually properly identified as a "Harmonic Damper" (one reason he named his business "Damper-Doctor" not Balancer-Vet!)) as that is its' purpose; and those that may aid in the balancing of the revolving assembly with the provision of offsetting mass should be just referenced as "Counter-Weighted-Dampers"; that versus "Non-Counter-Weighted" examples as utilized on so called "neutral" or internally (within crankcase) balanced rotating assemblies.

Damper units that do not carry any addition off-setting counterweight sum incorporated upon the inertia ring, this which may become mispositioned if the ring should turn on the hub, generally will not impart any significant vibration to the assembly until they are notably failed, and is easily identifiable with a casual observation (i.e.: is the inertia ring in place, is the elastomer in place, is the hub fastened tightly to the crank-snout?).

Oh, and do not start or run the engine without the damper properly installed, as it is the preload from the damper snout against the timing gear that maintains the gear in place (aka., without the damper force to hold the timing gear it may just shear the key and then............!) not mention the oil leak.

Scott.

 

Excellent post. Thanks for the clarification. One question. If you build a race engine with the rotating parts balanced professionally, are you saying that they omit the damper?

Cheers!

 

That would depend on a number of circumstances.

Generally with O.E.M. elastomer type dampers it is best for them to be incorporated in the balancing process; though perhaps in different sequences in the event depending on the intention or whim of the operator. Those dampers which possess an external counter-weight value should be considered as just an extension of the crankshaft and be present from the start; those which are non-counter-weighted or "neutral" are at times treated the same, but in this instance I prefer to "spin" the assembly, balancing the crankshaft without the damper, then add the damper, establish any (the) imbalance, and correct the damper so as it actually does present a "neutral" effect as intended, that as far as in the balancing effect as tested.

B.T.W. the same considerations apply to the flywheels & flexplates (that of the engines applicable in this inquiry).

Some shops will proclaim that in the instances of "neutral" assemblies, they will not require either item, as they are "neutral", and though this sounds reasonable, the addition of these items even though of "neutral" intention, but with inspection will induce an imbalance value; as just realize, as hard as we try nothing is "perfect", but if one tries hard enough you 'can' make it better!

Now, there are exceptions, for example, some dampers (and flywheels), as engineered, are not to be incorporated in the balancing process; this generally having something to do with manor in which the inertia ring mass is located and whether from a resting state and transitioning to the state as experienced in the balancing process, will it present itself as located as on the engine in it's functioning state.

Scott.

 

Read that a few times , and I think I get it .

 

Consider yourself lucky. Estimate on mine is $450.00 It sounds like he does an awesome job and there's a lot of interesting technology, but I'll stay with Plan B. I have a different one which I'll be using instead.

 

Sorry to hear that. He told me mine was kind of "easy" because it was the older timing chain cover, lower HP (327/300), and there were lots of them around.

He did tell me on the phone that depending on what it was when he got it, it could be a lot more because there are, evidently, rarer ones out there. Evidently you have one of those! I try to keep the car as original as possible even though it is a driver and never a show car. However, if mine had been that much, I believe I would have searched for an option!

Hope you get yours done without the higher expense!

Cheers!

 

Thanks, Scott. I appreciate you taking the time to explain this!

Cheers!