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2912 cc Timing

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BOBBYR

BOBBYR

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Hi Gang,
Lately,I've been doing pretty good getting the carburators straightened out on my 65.They adjust well to the point where my eyes aren't burning,when running in the garage.The acceleration on the road is really good too.I wanted to check the timing,but I'm not sure this should be done with a timing light.It seems my shop manual says that these motors should be static timed with a test light.My question is,What is the most accurate way of timing this motor?Thanks for any help you can give me.
Bobby R
 
I have an aftermarket dampener and Mallory dual-point distributor on my 3.0 (+ .030" = 180 c.i.) so it was easy to set the total advance using a timing light.

I'm hoping that our resident expert Dave R sees this, because I do not now remember the total number of degrees I used, but it was based on his recommendation to someone else; perhaps 32 to 34 degrees?

You could determine the same point on your dampener/pulley (seems there are some online references on how to mark the pulley, in degrees) and set time by total advance.
 
If the timing is way out so that the car won't start, you can set the initial timing to 10 deg. BTDC with a test light according to the procedure in the shop manual. This will get it running. Using a timing light, set it to 15 deg. BTDC.
The problem is that there is no marking on the pulley except for the TDC notch, so where are 10 deg. and 15 deg.?

The pulley circumference (at the flange where the notch is) is 19.5 inches exactly. With this information, it's possible to calculate the length on the circumference that will subtend angles of 10 deg. and 15 deg.
This results in 10 deg. = 0.54 inches and 15 deg. = 0.81 inches.

With the engine in the car, access is a bit limited for marking the pulley, but the way I did it was to measure off the required length on a piece of ribbon and temporarily stick it to the pulley (with contact cement) with one edge in the center of the TDC notch. Mark the other end with paint.
 
It is very important to make sure that the total advance, static plus centrifugal, vacuum disconnected, does not exceed about 34 to 36 degrees at 4,500 rpm.

Over advance can get into silent detonation which will rapidly damage an engine. It's silent because at higher rpm other engine/car noises are covering it up.

The safest way is to set the maximum advance to 35 degrees at high rpm with a timing light. Let the lower rpm advance fall where it may. There are just too many variables in a distributor's calibration to assure that setting static or low rpm timing to a given value will assure that the maximum advance is not exceeded.
D
 
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