If the new damper is off 2° then my timing light reads 8-10° off then its already at 10-12° false advance reading. My old damper had slipped 6-8°. I was shooting for a base of 21° at the time. This is assuming that the light and new damper are reading advanced. Taking all that in consideration then the 38° base I'm getting now is plausible. Im just spitballing as i havent checked TDC yet. Waiting on a piston stop to get here.

Durham Missouri

That doesn't really make sense if you think about it. Seems to me a more likely situation would be 38° Timing indication with a slipped damper.

Once that has been replaced with a serviceable unit timing is going to display something reasonable like 12° or whatever.

I have a notion its a combination of the slipped original damper,timing marks off a bit,and the timing light. Just using the numbers Ted offered and how much my damper has slipped(didn't notice until I had moved the timing) that would put me close to where I had the base set.

Durham Missouri

I’ve used a number of Powerbond harmonic dampers on the Y engines and never had any that was more than 2° off when checking TDC with the water-pump mounted timing pointer.  In Powerbond’s defense, I’ve found the same discrepancy when checking TDC on the factory dampers.  Besides the accuracy of the markings on the damper, there are many other factors to explain why the damper TDC does not agree with the timing pointer.  In most cases, a slight tweak of the timing pointer puts the TDC mark on the damper ‘right on’.
 
I second the thoughts on the ‘dial back’ timing lights in regards to inaccuracy.  While 8° is the most I’ve found them off, it does has an electrical circuit board so anything is possible.  Besides the timing light age being a factor, any time it has been dropped the accuracy becomes questionable.

Lorena, Texas (South of Waco)

It is a dial back. I've never had an issue with it before but anything's possible. I checked it's accuracy before but I can check it again. The thought has crossed my mind. I have a Sun timing light to compare it to.

Durham Missouri

Just another thought. What sort of timing light are you using? I have my suspicions about some of those that are adjustable to dial in the advance.

I guess it's possible that you got a bad one. I installed mine before putting the heads on checked it when #1 was on TDC the mark on the Power Bond was right on..

Ok. I had some free time and did a little work on the car. I changed out the advance bushing to a 18° and put in a little heavier springs. Still at 38°. If I rev the engine the marks advance. I'm beginning to have my suspicition about the marks on the balancer. I got to say so far I'm not too impressed with the Power Bond damper. I'll find TDC soon to confirm but it's got to be that. Nothing else has been changed.


Durham Missouri

It seemed very close to the drawing Ted posted. I was going to put the motor at tdc to double check. I do have lighter springs in the dizzy(MSD) but they are supposed to be all in at 2500. Just got the first snow of the season today so I'll have all winter to figure it out now.

Durham Missouri

It won't start with 38 degrees of advance so 38 probably is not the initial setting.  Since vacuum advance was disconnected, it was not adding to initial to make it appear to be 38.  Rev it some and see if the advance increases.  If it does not, then it is probably getting full advance at idle. If it does advance, see if it provides the normal amount  If it advances normally from 38, then you are probably getting an inaccurate indication some how.

Did you verify that the marks on the new damper are correct?  Ted's drawing provides you with a way  to check, if you don't have a known good original for comparison.





Lawrenceville, GA