mechanical advance only?

[tylerrocks]

Is there any con to running mechanical advance only? I can get 24* initial and 32* total this way.

Tyler

 

[Vinyl66]

That sure is a lot of initial timing. Anywhere from 32-36 is a good general range for total.

It will not hurt anything to run without vacuum advance. Most aftermarket distributors do not have them.
But vacuum advance does raise the timing under part throttle conditions (driving down expressway) to extend the burn cycle which results in better gas mileage.

 

[mfp4073]

mech advance only on my MSD billit distributor. The dyno numbers were showing better without it with my motor combo.

 

[tylerrocks]

Cool, It sure is alot more fun to drive this way.

Thanks,
Tyler

 

[mfp4073]

when I got to looking at my curves, I found that from idle to operational speed, I needed to go to full advance as fast as possible. Used the light springs and heavy weights and disconnected the vaccuum completely.

 

[Max Power]

It's do-able, but you have to set up the entire curve for it.

24 initial is a LOT and may cause starting problems.

 

[ForceFed70]

24* initial is about double what most people run...it may work at idle, but I think you'll have low RPM pinging.

The advantage to running vacum advance (along with mechanical) is improved fuel economy.