Harmonic Balancer for 302, need the circumference?

[dannystarr]

HELP!!  Need the circumference of the Z28 302 Harmonic Balancer. I am trying to break it up in 1/4's so I can adjust the valves cold. How do I do this with pulleys, hoses, belts and all the sh*# in the way?? ...Danny

[janobyte]

   email Cook, great thread on setting valves cold. Nice guy. Have not done it in years ,but he's right on the money. I switched to Harland Sharp's rockers ,beat the car and never had them out of spec again......when I ran a solid lifter  cam.

[dannystarr]

I have been searching for an hour for just the circumfernece! I tryed to do the math with the 8" but I couldn't remember how to do it. Dammit!!... Danny

[ko-lek-tor]

C=Pi x Diameter. Diameter for a 302 is 8 in (I believe). So, 8 x 3.14 (pi) = Circumfrence or 25.12 in. Divide by 4 (segments of a 1/4)=6.28. every 6.28 in. (6 and 5/16 approx. in. (exact would be 9/32) ) make a mark. This will give you 4 equal  spots around balancer. firing order 18436572. starting with 1 or LH 1st cyl and at TDC with both valves closed adjust. Turn Clock wise to next mark do #8 and so-forth. 2 revolutions does all 8.

[KurtS]

I have been searching for an hour for just the circumfernece! I tryed to do the math with the 8" but I couldn't remember how to do it. Dammit!!... Danny

Just google what you want: circumference 8 inch diameter
First hit gives the answer. 25.12

[dannystarr]

Got it everyone thanx so far...So I hate to sound stupid AGAIN... But should I make it 1/4" .25 on the end of that measurement, instead of the .28 ?... Reason being there is SOME paint around the balancer. So it could add up to 3 or 4 thousandths, or 1/16 of an inch. Does that 8 inches we have always heard about get measured with the balancer bare, no paint?... . Danny

[69Z28]

Danny...I did mine the same way your doing yours....with everything installed. Once I got the circumference measurement of the balancer I cut a piece of the firmest string I could find in my wife's sewing box, marked it and carefully taped it to the balancer. Used my hand dandy remote starter and clicked the engine around while I was under the car and made my marks on the balancer then. It worked for me. It may not be totally precise but I haven't had one problem adjusting the valves. When I do remove the engine I will do a more professional job or should I say accurate. Actually all I did was put a dot on the outside edge of the balancer large enough to see it when the engine rotated. Have you tried the timing tape? I did. The first time I cranked on it the tape disappeared. Never saw it again. I'm still chuckling about that one. As far as being painted or not I hardly believe there would be that much difference if there was paint on it. At least with the balancer marked in quarters you should be able to adjust it enough either way to adjust the valves. 

[Stingr69]

Wrap a measuring tape around the balancer.  Divide by 4.  Much more accurate and practical.  String is great too.

Make marks for every 90° and another mark for 36° advanced for setting the timing while you are at it.

BTW - "360° = Circumference" so measure around the damper then divide measurement by 10 to get the measurement for 36° point from the TDC mark.

-Mark.

[dannystarr]

I used a seamstress cloth tape and that seemed to work well. Lays nice and flat. I had the measurement at 25.25 with the cloth tape. I just wanted to make sure it was accurate. Apparently I was off. I here ya on the 36 degrees. That would be around 2 -1/2". So I will get that accurate and make a mark there also. Thanx everyone... Gonna do it tonight... Danny