[Zooguy]

Question for everybody 1966 389. Is there a mark on the factory balancer that shows top dead center? I put my MSD pro billet distributor in today and I want to make sure I have it lined up correctly. I know there's a Mark that whips around and it corresponds with the 046 marker but I don't know what the 046 marker is actually indicating.

[1_Wild_Cat]

The marks indicate 0-4-6 degrees before top dead center. So the line on the balancer lined up with the 0 should be TDC. You need to verify that it is TDC of the compression stroke by observing the valve position.

[25stevem]

Those balancer marks only reference number 1 piston being at or near TDC.

It’s still possible to not have the cam installed right to also have both valves not being closed at TDC like they need to be.

When the piston is at TDC then number 6 exh valve should be open somewhat.

If this is the case then you can drop the Dizzy in with the rotor facing a head of number one cap tower a little bit.

Remember that the Pontiac Dizzy spins counter clockwise.

I like to not install the timing cover, valley pan and intake until I confirm I know which way to drop the Dizzy in.

If your piston is at TDC, but one of the valves is open on number one cylinder then you need to have the Dizzy rotor facing number 6, not number one.
All this means is that you have the cam gear set up 180 degrees out and is absolutely no problem as long as the Dizzy goes in the motor the needed way,

[25stevem]

By the way those balancer marks are minus 4 degrees, 0 and +6 just to make sure where all on the same page.

If the balancer is not on the motor yet then I would carefully measure from 0 to 6 and then with a hack saw cut 5 more notches in the balancer.
Then you will have marks at 12,18,24 30 and 36 which will make checking your total timing without vacuum advance easy.

[mgarblik]

Originally Posted by 25stevem

By the way those balancer marks are minus 4 degrees, 0 and +6 just to make sure where all on the same page.

If the balancer is not on the motor yet then I would carefully measure from 0 to 6 and then with a hack saw cut 5 more notches in the balancer.
Then you will have marks at 12,18,24 30 and 36 which will make checking your total timing without vacuum advance easy.

This is an excellent idea mentioned above. BTW, the PowerBond replacement balancer sold by Summit, Butler, and others is degreed to 60 degrees or so. BUT BEWARE. All the numbers come off with brake clean and a rag. (Ask me how I know) Then you have NO numbers and no 0 reference. Nice balancer otherwise.

[25stevem]

I had that same thing take place with that brand balancer, only I did not loose all the markings .

On the ones that remained I sprayed a epoxy clear coat over them after a redid the wiped off makings with black marker.

We always seem to reach for brakekleen when we should be trying Windex first, lol!

[Zooguy]

Okay guys thanks .... So tdc #1 is the lil notch in the balancer. And the 0 on the "timing pointer" is tdc#1 .... So if i get the diameter of the balancer i can order some timing tape from jegs/summit and know what my timing is while running? Am i thinking correctly?

Distributor is locked out so no timing curve To adjust. (I am aware of the drawbacks of no timing curve)

[25stevem]

Did you choose to have a Dizzy with no curve?

Besides the drawbacks that kind of thing is for a race only motor where the motors power band is aways above the rpm where the full advance would be in anyway.

[mgarblik]

Originally Posted by Zooguy

Okay guys thanks .... So tdc #1 is the lil notch in the balancer. And the 0 on the "timing pointer" is tdc#1 .... So if i get the diameter of the balancer i can order some timing tape from jegs/summit and know what my timing is while running? Am i thinking correctly?

Distributor is locked out so no timing curve To adjust. (I am aware of the drawbacks of no timing curve)

Timing tape would work. But personally I prefer to use a dial back timing light. Then all you need it a zero mark on the balancer. However, a dial back light generally doesn't work with a MSD or other multi spark ignition. Then you would need tape or a degreed balancer.

[Zooguy]

So I think I did it right I actually had to turn the oil pump drive shaft slightly to get the distributor lined up on cylinder number one.

[Zooguy]

...

[25stevem]

To make things easier you can just drop the Dizzy in with the rotor pointing where you want it.

Next install the Dizzy hold down clamp only very lightly so the Dizzy can not pop up from where it is by the amount that could disengage the two gears.

Next do whats needed to kill the spark and then crank the motor over 2 complete revolutions and the Dizzy will load itself right onto the oil pump drive shaft for you.

[Stan Weiss]

Originally Posted by Zooguy

Question for everybody 1966 389. Is there a mark on the factory balancer that shows top dead center? I put my MSD pro billet distributor in today and I want to make sure I have it lined up correctly. I know there's a Mark that whips around and it corresponds with the 046 marker but I don't know what the 046 marker is actually indicating.

The question is. How accurate are the marks? Just like one should always degree in a cam, one should check if TDC is truly when these marks line up.

Stan

PS let me add if you can get an accurate measurement of the balancer diameter you can calcuclate where to put your marks.

Balancer Distance for Every
Diameter 6 Degrees
3.80000 0.19897
3.90000 0.2042
4.00000 0.20944
4.10000 0.21468
4.20000 0.21991
4.30000 0.22515
4.40000 0.23038
4.50000 0.23562
4.60000 0.24086
4.70000 0.24609
4.80000 0.25133
4.90000 0.25656
5.00000 0.2618
5.10000 0.26704
5.20000 0.27227
5.30000 0.27751
5.40000 0.28274
5.50000 0.28798
5.60000 0.29322
5.70000 0.29845

[Zooguy]

Can anybody confirm the diameter of my 1966 dampener I think it's 5.75"

[25stevem]

5.250”, the 68 and up balancers where 6.750”.
This info is from my ancient HO racing guide.
At the moment I do not have either a early or a late one to confirm this for you.

[ftwmlp]

Originally Posted by Zooguy

Can anybody confirm the diameter of my 1966 dampener I think it's 5.75"

I think where I get all screwed up is in the nomenclature. In the attached pic which some helpful member posted in the past, the actual balancer is the first piece on the right of the pic?, and its diameter is 5.75". Nowhere on that piece are marks to denote timing. What is not in this picture is the Hub that mounts on the crank snout, and its diameter is 5.25", with a mark to denote 0.

As B-Man explains in a post over in the 66-67 Section, the hub is what needs to be measured when making your own marks and he provides a quick way to do so.

[Zooguy]

I used the 5.25" tape here ... Is that the correct size and location?

[25stevem]

Yes it’s right!

The dash markings on the tape match those on the timing cover tab, and actually with surprising accuracy!

[Zooguy]

Thank you I believe I actually got the tape 1.25 to 1.5° off of the actual mark on the hub but that should be okay as long as I'm conservative with the timing.

[25stevem]

Yes it’s off a smidge, but you know that and like you say be conservative.