Exact timing numbers

[Anonymous]

Is there a way I can get a more accurate reading for my timing? I've been using an old timing light. I think the harmonic balance is off.

Is it unusual to get approx. 30 degrees of initial advance out of these old engines? I can reach that number before my engine started stumbling.

Just curious.



-Chris

 

[Lazy JW]

You will need to verify the timing marks on the damper. Make a physical stop that you can screw into the spark plug hole. It is best if it will stop the piston about 1/2 inch before TDC. With all spark plugs removed (for safety) slowly rotate the engine by hand until the piston just contacts the stop. Gently, (we want a physical stop, not a hole in the piston). Make a pencil mark on the damper at the timing pointer. Now, rotate the other direction to the stop, make a mark there also. True TDC is exactly halfway between the two marks. If the factory marks are elsewhere, the damper has slipped. You can make a physical stop by breaking the insulator out of an old spark plug, then threading the inside with a tap. You then turn an appropriate length bolt in to create the stop, which can then be adjusted for proper stopping point. Sometimes those spark plugs can be a real bugger to break apart though. Good luck.
Joe

 

[Anonymous]

Awesome idea!

One dumb question. How do I know what the correct number of turns would be into the cylinder? I mean, I can go too far into the cylinder, right?



-Chris

 

[gtm1086]

The way you make the timing stop work is. You go just past top dead center. Install your timing stop. "The old spark plug with a bolt down the center trick works very well" Adjust the bolt down to were is just touches the piston. You can tell this because you will not be able to turn turn the engine counter clock wise. Make a mark on your balancer. Now turn the engine over clock wise until the piston comes back up and touches the bolt. make another mark. measure the half way distance and that is your true top dead center.

 

[CZLN6]

Howdy Chris:

Yes, it is unusual to get 30 degrees of initial advance on these engines.

Did you disconnect and plug the vacuum advance line between the carb and the distributor?

Are you using a quality timing light?

It is always a good idea to verify the timing mark on these old engines.

Adios, David