Timing Trouble

65shelby · Jan 6, 2009

My '65 block was rebuilt as a 331 stroker using a scat crankshaft part number 4-302-3250-5400. My builder reused the original damper and the original timing cover which has the pointer on the driver side. Now that I have the motor back in the car and running, when I tried to adjust the timing to about 12 degrees advanced, the motor just dies as I get near 12 degrees. It seems to run well at 30 degrees. Now I know that it is probably not really 30 degrees base advanced. I think that the timing marks on the damper are not in the right place to work with the crankshaft and the timing cover. Can anyone validate this for me and tell me how I would need to go about adjusting the timing now. My guess is that I need to find TDC using a piston stop and then when I find it, make a mark on the damper at the timing pointer. Then I would need to using a timing tape to adjust the timing. Basically, I looking for anyone that can validate this and give me some advice on what I need to do. Thanks

D.Hearne · Jan 6, 2009

More likely the balancer's outer ring has slipped. If you're still using the balancer that came with the timing cover, that's where the problem is. The crankshaft shouldn't be the cause, unless the keyway for the balancer key is cut in the wrong position.

TOM B · Jan 7, 2009

I agree with D Hearne, I had a few stock balancers slip, sometimes you cant see
it but the timing is way off, get a new balencer for that 331 stroker and through that stock one in the trash, It will run better and smoother, when the engine has the right balance and timing, your throttle responce will be alsome dood.

rbohm · Jan 8, 2009

as mentioned the possibility of the balancer ring slipping is quite possible. but before you toss the balancer, make sure your vacuum advance is disconected and plugged, and that you mechanicla advance is working properly.

65shelby · Jan 11, 2009

I hear what you guys are saying but the balancer is a brand new reproduction item from Virginia classic mustang. Take a look at the attached pics of the motor. The first shows the #1 at TDC and the second, although not clear, shows the timing pointer at TDC on the balancer. Is it possible that the distributor was installed one tooth off. Would this create a reading of 30 degrees advance when running well and not running at all at 12 degrees advance as indicated on the balancer?

D.Hearne · Jan 11, 2009

Being a tooth off doesn't affect the timing readings. It does affect the amount if travel in the swing of the vacuum advance pod. The difference in the pointer and the timing marks are due to the marks being in the wrong position on the balancer. Get some "Timing Tape" and correct it.

65shelby · Jan 12, 2009

Thanks for the advice, I appreciate it.

pabear89 · Jan 12, 2009

65shelby said:
I hear what you guys are saying but the balancer is a brand new reproduction item from Virginia classic mustang. Take a look at the attached pics of the motor. The first shows the #1 at TDC and the second, although not clear, shows the timing pointer at TDC on the balancer. Is it possible that the distributor was installed one tooth off. Would this create a reading of 30 degrees advance when running well and not running at all at 12 degrees advance as indicated on the balancer?

From info you posted, sounds like you have the vac advance hooked to a constant vac source and not a ported one.
This is what is advancing the timing to 30 while running.
Unknown rpm reading when trying to set timing, too high and the centrfical weights may be adding to int timing also.

65shelby · Jan 13, 2009

Thanks for the advice, however I do have the vacuum line disconnected from the distributor and plugged at the carb, so the vacuum should not be adding timing. I'm also using a timing light with a tach and the 30 degree readings are at around 750 to 800 rpm, so I would not expect to see any centrifugal advance at that speed. I'm going to call the guy who built the engine and see what he thinks, but I am pretty certain that the damper and timing pointer are not in alignment. I think the best solution is to put a degree wheel on it and use a piston stop through the spark plug whole to verify TDC. I'm just surprised that the guy who built the engine would not have noticed this misalignment in the build process. I suppose, however that he would have used his own pointer and degree wheel and would not have been concered with TDC on the damper and it's relationship to the pointer on the timing cover. Thanks

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