Hey. I posted this over in the "what timing is everyone running" thread but the post was ignored, so...

I was wondering what the consequences of running really advanced timing are in the long run. Are there any at all? right now i'm prob running 8-10* advanced.. when i bought the car that's where it was set, and when i retarted the timing back to TDC, it sounded much better but ran like **** (decrease in fuel economy as well as a big loss in power)

But, on the LG4, the recommended setting is 0* BTDC.

Sooo are there any consequences (long run and/or short) of running advanced??


Thanks

 

I did it on my first car (67 GTO w/400) many years ago. Ran really good; for abt a week. Then started smoking badly and fouling plugs. When I tore down eng, found the area between the 2 compression rings was shattered and chunks were missing on most of the pistons.
Won't do that again.

 

well advanced timing will give some more power. the way to check how far to advance it is to start advancing it until it starts to knock the take it back some where it doesnt knock. that is how i set mine. i run around 8-9 btdc. at 10 it didnt do anything but started to ping at 11 so i put it at 8-9

 

My LG4 ('83 camaro,) is recommended to run timing of 6 degrees btdc. I'm pretty sure all LG4's were the same, no?

Also, how people are saying about the advancing until you hear the ping and backing off, won't the engine ping while under a load (the car being driven,) before it'll ping at idle?

 

The sticker right on the hood of my LG4 says 0* BTDC....

 

Umm yeah.. you dont listen for pinging at idle. The engine will probably shut off before it starts pinging at idle. You go run it at WOT and you listen for pining. Then you back off the timing accordingly.

 

Advance it 'till it pings and then back off has a few problems:

1) You'll be running the most timing your motor can take. This is not necessarily the timing that makes the most power. I've seen plenty of magazines etc where they were running 34 deg total advance and backed it down to 31-32 and gained a few horses, even though the motor wasn't detonating at 34.

2) If you have a knock sensor (AFAIK the only V8 motors that do NOT are 82-84 LG4s), the knock sensor will detect detonation before it becomes audible and retard the timing to compensate. If you want to do it this way, you'll have to modify the "advance to ping" method by using a scan tool and advance until you get knock counts, then back off. That's what I did on mine, anyway.

 

This, of course, all depends upon the timing marks on a 10+ year old harmonic balancer being in the correct position.

The advantages of running more advance are increased fuel mileage, more power, and more efficient and cleaner operation. Of course, anything can be done excessively, and there is a point where advance becomess detrimental.

On the "Dark Side", too much retard will result in overheating, incomplete combustion, lower power, greater HC emissions, and the possibility of burning exhaust valves and their seats.

Set it where it runs best overall. This may take some time to determine. Analyzing the spark plug condition, fuel mileage, and power output may take some time to arrive at the best setting for your particular application. A scan tool could speed up the process quite a bit.

 

I forgot to mention that that's ONE benefit of "advance it 'till it pings"--you're not relying on the timing marks on the balancer, only on feedback from the motor.