Hello,
OK now maybe this has been covered before, but would someone please indulge me and explain this to me?
I want to set the timing on the car, but not just the base timing at idle.
What i want to do is set initial timing, and then understand mechanical advance, and vacuum advance, and total timing, and most importantly , how do i KNOW what i have, and when do these come into play?
thank-you.

Use the search function and type in "distributor recurve". It will have everything you wanted to know or ask and some great pictures of the parts.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Howdy

I'm gonna try to give you the skinny on this very complex subject while trying to keep it simple. I am not an expert but I have gotten lots of help as I dove into this subject with my smallblock mopar, and more lately with my slant.

You need a timing light and a way to determine top dead center on cyl. #1. A 'dial back' timing light or new tape with more degrees marked for the balancer is very helpful.

The first job is to verify the timing mark on the balancer. You want to make sure it is accurate and you might need a white or silver paint pen or something to make it easy to see. A 'dial back' timing light will be very helpful only if the mark is correct- the outer ring of the balancer has been known to slip to a wrong position after years of service.

Take the hose off the vac. advance can on the distributor and plug it. Get the motor running and shine the light at the balancer. The strobe will correspond to the #1 spark, showing you a static timing mark in relation to TDC. Have the distributor hold down snug but loosened so you can slowly twist it back and forth. Observe the difference in timing. This is your initial timing- the timing at idle.

Next is mechanical advance. There are weights in the distributor that sling out against the resistance of two little springs as the rotor spins faster with rpm. As the weights move out the rotor is twisted to add timing. The springs determine how fast the additional timing comes in. You can change them for different ones to tailor your curve. In general for performance you want the timing to come in as fast as possible without knocking or pinging. The amount of advance is limited by a plate with two slots in it. There are different ones for different setups from the factory. You can take the dist. apart and modify them to limit the amount of mechanical timing that can be applied. Usually this is done to allow more initial timing which is needed by modified engines that are less efficient at idle (but might scream at high rpm) without exceeding the maximum total timing for the engine.

example: My 408 smallblock idled like crap with 10* initial timing but would knock at high rpm with more than 36*. If I set the stock distributor at 18*initial like the engine wanted it would advance into the 40*s with rpm. No good. I had to limit the mechanical advance. This can be done by welding or epoxying the slots in the governor (plate with slots).

Vac. advance is mainly for efficiency and mileage. At light loads (cruising, light throttle) the engine can stand much more timing than when its working hard. You can look for the #s on the vac. module on the side of the dist. or just hook up a mity-vac to the distributor and watch the timing mark move with the light as you apply suction. Some units you can stick a small allen in the hole to tune it a little. This is the last thing you want to mess with in this process. There should be no vac. advance at idle.

Total timing is intial plus mechanical. The word on the street is that slants like about 30*

Ok, Got it?

radar

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madam im adam

Hey gentlemen ,
thank-you for your replies. Im going to search it out and i appreciate the help. I have done the base timing on the slant, but guess now its time to delve into the subject deeper. Thanks again.