As a general rule when you retard your timing does your react with a hesitation or stop pulling in the higher rpm range?

Both?

The effect is most noticeable at low rpm. Lower Idle speed, rough idle, possible backfiiring, bogging, and hesitation are all signs of not enough advance down low.

At high rpm, the mechanical advance is throwing timing in, so the only effect you'd have is reduced power, and that would only be noticeable if you've run it with more and know the difference.

General question here----when you retard your ignition timing does your car lose power in the higher rpm range? I.e. just stop pulling and hesitate slightly in the higher rpm range.

Thanks guys

JimM

That makes sense---but I am only experiencing the "falling off" effect at higher rpm. It did pop through the carb once in second gear as I was working up the rpm's. I have not driven it in about a month so maybe something else. I do have those cheap packard plug wires on there that are correct date coded but not much for performance.
Tomorrow if it is nice I will take if for a spin to see if it happens again.

Those 302's love a lot of advance. If it was retarded to guard against pinging, that is not usually a problem with a stock built 302. Retarded timing can cause the engine to run warmer.

Oh yes. In fact your car will loose power any time the timing is too retarded or too advanced. There are several adjustments to make to your distributor to affect total advance, vacuum advance, and centrifical advance all of which will affect timing at various load/rpms. Give us some more details on what your motor is like and how you have it set up.

Gary,

Thanks---I am going to dial a bit more timing into it. I know this sounds weird, but it seems to run better after around 10 miles of normal driving.

[QUOTE=dnult;665363]Oh yes. In fact your car will loose power any time the timing is too retarded or too advanced. There are several adjustments to make to your distributor to affect total advance, vacuum advance, and centrifical advance all of which will affect timing at various load/rpms. Give us some more details on what your motor is like and how you have it set up.

Dave,

It is set up as a stock 302 with 10 degrees static and 34 total ignition timing. When I bought the car it ran like a scalded dog with 16 degrees static. I started playing with it and noticed how much timing it had and what the manuals said was stock so I dialed it back down. I test drove it after I dialed it back down and it seemed to run ok. I also run 110 octane fuel of course with no pinging with the 16 degree timing. But with 93 octane and the 16 degree timing it pings. Another reason I wanted to dial it down. An interesting thing that I have noticed that after about 10- 15 miles of normal driving it seems to run better---pulls harder through the higher revs.

The carb is a new 780 Holley, the distributor is stock the plug wires are those awful packard date coded wires. I have not driven the car for a month or so then took it out and noticed this. This morning went on a long cruise and it seemed to clear up. I don't beat on the car that much anyway, but just want it to run smooth and sweet. Any advice is helpful.

thanks for your help:hurray:

Larry I merged your two threads on the same subject into one. No need to post the same thing more than once...

Every engine combo is a bit different. Timing is like shooting at a moving target. You lead your target too much and the shot is in front of the target (too advanced). If you don't lead the target enough the shot is behind it (too retarded). You want the spark to ignite the burn in the cyl just as it goes over TDC so it can help push the piston down in the cyl. Too much advance and the piston is already down in the cyl and the burn doesn't push it as hard as it could. Have the burn start before the piston crosses TDC and the burn actually trys to send the piston back down when it is still moving up in the cyl.

There are basic patterns based on type of engines (bore and stroke) but cams, heads, carbs and exhaust can play a big part in making each engine just a little different...