Harmonic Balancer date coded?

[John C.]

Pulled my '64 365HP balancer off. I figured the balancer outer ring had slipped somewhat since I couldn't get the balancer timing mark anywhere near the pointer...and the engine ran like a champ!

Anyway, it was a real joy pulling that sucker off. Since I had it in my hands I thought I'd give a good eyeballin' to see what was there. I found a "B64" stamped on the backside of the outer ring. I must assume that decodes as Febuary 1964?

Another thing, I found that the hole in the frame's front cross-member has a real purpose...to catch one of the bolts for the fan/upper pulley/water pump as I fumbled around trying to get those to line up! Man, I love my vette!

[John C.]

Re: Harmonic Balancer date coded?

I'll reply to my own post. Found my answer on p. 141 of Adams' book: yes, they are date coded and B64 should decode as February 1964.

[David D.]

Re: Harmonic Balancer date coded?

I'll reply to my own post. Found my answer on p. 141 of Adams' book: yes, they are date coded and B64 should decode as February 1964.

John ,
Should also have p/n 3817173 on it.....The key way and timing mark should be perfectly aligned.....

BTW-I like your car.....similar tastes

David

[John C.]

Re: Harmonic Balancer date coded?

John ,
Should also have p/n 3817173 on it.....The key way and timing mark should be perfectly aligned.....

BTW-I like your car.....similar tastes

David

Brilliant minds think alike!

Hmmm, key way and timing mark are perfectly aligned.

What gives? I didn't think there was any way the thing could run with the timing that far off??? I couldn't even SEE the timing mark while it was running.

[David D.]

Re: Harmonic Balancer date coded?

Brilliant minds think alike!

Hmmm, key way and timing mark are perfectly aligned.

What gives? I didn't think there was any way the thing could run with the timing that far off??? I couldn't even SEE the timing mark while it was running.

Not sure....maybe dizzy is installed a little wrong? Gonna need a more brilliant mind than mine to answer that question.....but I'll be watchin for an answer and your reply to resolution.
David

[Michael H.]

Re: Harmonic Balancer date coded?

Brilliant minds think alike!

Hmmm, key way and timing mark are perfectly aligned.

What gives? I didn't think there was any way the thing could run with the timing that far off??? I couldn't even SEE the timing mark while it was running.

John, are you absolutely sure that you had the timing light hooked up to the #1 cylinder wire? (I always use the coil wire instead of #1 if possible)

Was the vacuum advance line disconnected?

[John C.]

Re: Harmonic Balancer date coded?

Yes, definitely on #1 (first cylinder on driver's side, right?) and vacuum advance plugged.

I just found it hard to believe that it could run with it that far off and the balancer NOT be off...oh well I don't do this stuff for a living, or else I'd starve!

[Michael H.]

Re: Harmonic Balancer date coded?

Yes, definitely on #1 (first cylinder on driver's side, right?) and vacuum advance plugged.

I just found it hard to believe that it could run with it that far off and the balancer NOT be off...oh well I don't do this stuff for a living, or else I'd starve!

Yup, they'll run that way if the timing is that far off. Sound healthy in the garage too but won't make much power on the street. Timing can probably be as much as 20 or more degrees advanced and still start/run ok.
If the cam timing marks align properly, I would have to guess the problem is elsewhere.

[John C.]

Re: Harmonic Balancer date coded?

UPDATE
Yes, it was this bumbling mechanic that caused my own problems. I must have re-installed the distributor 20 or so degrees off when I installed the Pertronix ignition. I thought I had installed it properly then because it fired up immediately. However, it always ran like crap (lots of pinging unless the throttle was really opened slowly) when I took it for a spin.

So I pulled the distributor, took my time, and re-installed it 15 degrees advanced. Fired right up! Man, that 30-30 cam has such a wicked idle! I then put the timing light on it and then went for a drive. Ran like a scalded dog!

However, anyone ever have the problem of spark plug wires coming off for no apparent reason? I have to reinstall the damn things ever so often. I'm thinking maybe the header gasket leaks are blowing them off...but I've been wrong before!

[Mike B.]

Re: Harmonic Balancer date coded?

Another cause of timing marks not lining up is that the timing tab position was changed from around 1969 onwards to allow a better view as more accessories were bolted on, blocking the original tab position. I believe that the tab was moved 10 degrees down.

But since the timing cover fit is universal on SBCs from the '50s to the 80s, it is not uncommon to have a cover with a wrongly positioned tab mounted on an earlier generation engine and vice-versa.

Don't ask me how I know!

Mike

[Mike E.]

Re: Harmonic Balancer date coded?

They began dating the finned balancers some time in the 1962 model year. My experience is that they were not dated yet in early December of 61--don't know exactly when they started.

[Robert K.]

Re: Harmonic Balancer date coded?

Mike, I have an NOS balancer date A62.

[Wayne M.]

Re: Harmonic Balancer date coded?

My early '65 eight inch balancer has "H64" stamped on the finned side.