VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 '32 Harmonic balancer

I know this topic has been covered here many times. I did a search of old threads and came up with 8 pages of discussion. I read them all.

My harmonic balancer installation preference would be to drill and tap the front of the crankshaft and fabricate a tool rather than use the BFH and a wooden block (if I did it that way I'd probably machine a piece of Delrin to fit over the crank teeth on the balancer).

Anyway, of the threads dealing with drilling and tapping the crankshaft, I noted Mark Yeaman's and Denny Graham's posts from 2011 where they showed photos of making drill guides to help get straight holes in the crankshaft. The recommendation was to drill and tap so an installation tool could be made out of 7/16-20 all thread.

I made the drill guides and before I drilled the crankshaft in the engine I plan to use, I tried drilling a totally trashed crankshaft to see how my guides worked. The hole looked nice and straight, but took out the bottom of the key way. Is that going to be a problem? (Quick solution --- grind off the bottom of the key so it doesn't interfere with the threads) Is 7/16-20 still the preferred size of all thread to use?

Am I really just being too cautious with this process? I've already ruined a cylinder head. I really don't want to mess up a crankshaft too, but if the BFH really is an acceptable method, I'd chalk up my time on the lathe making the guides as a learning experience and still time well spent.

Another question --- if I bead blast the balancer prior to paint, will that affect its function if I can't blow out all the bead blast media?

Thanks. Tom

The BFH with a hardwood block method has been used for years without any detrimental effects. I am not sure where the bead blast material might lodge and not be removable. After blowing out I suggest a good wash job-plain old soap and water and a hot rinse and blow dry to prevent flash rusting.

I used a large pipe that just fits around the crank "teeth" and you will damage the balancer if you put pressure on the outer rim. Thousands/millions have been installed with a hammmer and never had a problem, I would NOT sand blast any part of the balancer.

I have used a pipe to install the balancer on several engines. Be sure to install bolts to hold the balancer parts tight together. Otherwise you will be taking it off try to tighten it.

The BFH and a wood block works fine. I used that method on my car and had no problems. If you really don't know what you are doing have a professional mechanic do it for you so that you don't end up with a broken balancer like you did with the cylinder head.

I reiterate the need to bolt the balancer parts tight together no matter if an amateur or professional. There are "springs" between the weight and pulley held in by circular retainers that will bend with enough stress. Straightening the retainers is difficult at best.

They go back on easier than you would think.

I`m about to install balancer on my 1932 engine, and have read several threads regarding this, and understand that, as this thread also confirm, it`s ok to use hammer with a piece of pipe or wooden block on center of balancer after it`s bolted together, but isn`t it needed to protect thrust on main bearings in some way?
Do you oil end of crank, or help it in any other way to slide eaiser on?

Hei Morten

In the past, when I've driven a part on and didn't want to risk having the part "get stuck" half way on and not able to drive it on further...
I've used a ZDDP oil additive, or camshaft break-in lube with ZDDP in it, to lubricate the shaft first.
Seems to help.

Does the ZDDP itself do anything, or is it just very thin penetrading products?

No need or way to protect main bearings?

ZDDP is zinc dialkyldithiophosphate

simply an anti wear agent

i used a different anti wear when i built my engine, mainly to keep it lubricated until you can run it and the oil pump and oil takes over dont want to start or run them dry !!