Timing ?'s Here we go again.
 

OK heres my combo, and dont laugh. 306, forged stock dish pistons, stock roller, mildly ported e7's, headman 1-3/4 long tubes, Wieand stealth intake, holley 650 d.p. I will be running NO front accessories, and a vacuum advance distributor. I am running a Moroso water pump drive also if that makes a difference. What do you guys recommend for optimal timing. I am building the tranny this week hopefully and gonna start this beast next week. I would like to tune and play with the carb and timing as much as possible now before the season starts and hopefully learn how to tune this myself as my guru is the know how right now.

Thanks
Brad

I would start with about 12*-14* and paly with it some to see what motor works with best. But to find the limit advance it a couple degrees at a time until it pings. Once it ping retard it 1*2* for a safe setting.

I would start at 30 degrees total advance, and go up till the power drops off.

Thanks guys
 

Thanks guys. Could you also explain the difference in intial and total timing. I think I know but not sure.

Thanks again
Brad

you might know this But the headers you have a Over kill big time 1 3/4in on those heads well I bet you know Just Why did you go with those??? might be better off Getting a 1 5/8

I did some research and I thought I was getting a good thing when I bought the headers, I guess I should have done more huh. Why do you say they are to big? The heads are E7's and I know that hurts me but hte are real smooth and flow strait fast air. They may not have much volume but they do help.

Timing and exhaust
 

Brad:

Total or maximum timing is usually 36-38 on a mildly modified engine. That means the timing at top RPM (5500) as opposed to static timing which is done at idle and should be around 14 degrees.

The large-volume headers, while great for high RPM applications, limit velocity at lower RPM's and can actually slow you down on the low end.
Smaller diameter tubes will generate higher velocity to "scavenge" or pull the spent exhaust out of the cylinder but having long-tube headers will help offset the large volume somewhat and although your ported E7's and stock cam don't really require 1 3/4" headers, if you're happy with the performance, don't worry about it.

Mr 5 0, thanks that has really cleared up some things. As far as the performance of the big headers, I dont know yet how they will perform. I am just rumming the headers nad turndowns so I think they "scavenging" effect will be there goint down the track. Maybe the outside air will help pull the gasses out. And also, as far as the bigger headers being for higher turning motor's I plan on keeping this one above 5 most of the time. I jsut hope it will last.

Brad

when adjusting the timing, are you supposed to do it with the electrical connector disconnected? or can you just do it by turning the distributor and thats it?
if so, why is that? can someone explain....

thanks,
adam

avbcon you must disconnect the spout connector. It is an electric advance. When you adjust timing you are adjusting "base" timing, not advanced. The spout connector is like a vacum line on carbed applications. Hope this clears up your question. John BTW dont go more than 14-15 degrees of base timing, as to much advance kills your top end power

OK I'm runnig a vacuum advance distributor. Are you saying I should pull the vacuum line from teh carb off while adjusting the timing? Also do I set the timing at base and check the total timing before or after I reconnect the vacuum line?

Thanks again
Brad

pony power pull it and plug the line. once its done and you connect the vac line back up have a buddy rev motor to 2,000 rpm or above and check for total it should be around 38 to 40 degrees

Thanks John

Really. What is your ECM out of?

No ECM. Just a MSD box to control spark.

Gee, if I had just re-read your first post, I would have known that! Sorry. The mention of the spout connector confused me.

FWIW, just to clarify, in ECM controlled engines, the ECM controls the ignition timing, so the only way to set the base timing is to kill the signal going to the ECM so that the ECM no longer can control it, and you end up with base timing. That's what the spout connector does. Since you have no ECM, then you have no spout connector to worry about. You do need to disconnect and plug the vacuum hose going to the distributor when you set your timing. Total timing is the total combined timing advance from the vacuum and mechanical advance units, plus the base timing. You measure this after you are finished.

Take care,
-Chris

Cool, thanks guys. I admit the first time I read that stuff about the spout connector it confused me to. I figured it out eventually.

Brad