If I slow the base timing down it runs great at high RPM and like a slug at low rpm. With timing set decent at idle, it has excellent low rpm acceleration and when it comes in full (around 3500 or so) she starts to pop a little out the tailpipes and just isn’t right– so, I’m pretty sure I need to limit my full advance..

Yea, I know I need to set it at 36* etc, and will do so when I get a better timing light – the question is how to limit full.. gonna experiment poor boy style for now..

Thanks in advance…

 

If you have a mechanical advance distributor, there are various aftermarket parts available to modify the advance curve. I'm not sure about the newer distributors. Spring kits to control the rate of centrifical advance, adjustable vacume units, and a adjustable stop for total advance. Check out Summit or Jegs catalogs. There has been alot of threads on the forum about this. Check the archives.

 

the search stuff here is normally poor at best...i know how all that other stuff works and i'm looking for mechanical stop info..thanks anyway

 

Distributor mechanical advance questions

Search function is truely a wonderful thing.

 

thanks...what did you use to search?

nice wink..

 

 

Hey Lonnie
To limit the mechanical advance you need to install a limiter on the advance stop just under the distributor plate. Its a post the swings through an arched opening in the bottom plate. There are kits for points and HEI distributors available from Summit which include weights, springs, and limiters. Mr. Gasket makes them among others. You should also measure the diameter of the balancer and get a timing tape to match the size. Put the timing tape on and run the distributor without weights for the initial setting. Rev the engine to about 2500 rpm and set the timing for where you want max without the vacuum advance connected. Then stop the engine and install the advance springs. Check your timing then at idle. You will probably be running around 14 to 18 degrees initial. Run the car like that and see how you like it. If it pings set it back a little. I found on my car that 34 degree max advance works better than 36 or 38 degrees. Once you've got the mechanical advance set right you can address the vacuum advance. The stock vacuum can has a lot of advance in it and may cause pinging or misfire at low speed under light loads. I changed mine out to a 10 degree can that Lars recommended in his paper. Works slicker than snot. Good luck and drop me a line if you get stuck.

 

thanks Al...my weekend project appears to be lined up..