I'm just curious to see what everyone has their base/idle timing set for. I have mine about 12 degrees advanced, and the cam is installed with +2 degrees. Does that +2 degrees show up on the scale? Or do I have to add it in with what I see on the scale?


If I were to back off to maybe 6 or 8 degrees advanced, would I notice any better fuel economy for cruising?

 

Just to clarify: Cam (valve) timing and ignition timing are too very different things. When figuring out ignition timing don't worry about cam timing.

 

I just set mine to where it ran the best. Its around 8* i think.

 

8* for me too- seems to perform best at this setting

 

Cam timing and ignition timing is not the same thing, and is not added together or even looked at together.

I don't beleive in setting timing based on Initial (idel) figures only. GM done some screwy things with the weights and stops in thier dist. I seen GM dist give all kinda strange amounts of mech. advance... so.....

I set for total timing and let Initial timing fall where it falls.

To check total timing you'll need 1 of the 3..
dail back advance timing light
reg. light and a degreed damper
or reg. light and reg. damper with a timing tape on it

Then to know what you need for total timing you look at your specs. Like head chamber shape. The bowl type chambers will need more timing than heart of kindy shaped chambers.

Most bowl chamber SBC's like 34-38* total.

Also time it in 500 or so rpm steps. This away you can check the rate of advance and timing curve. Go from idel, all the way to say 3500 rpm or so with the engine, and wrire down the numbers and rpm.

Stock springs in the GM dist. has total timing in at 4000 rpm-5000 rpm... Thats way too high, you hardly ever will have full timing.

You want all your advance to be in at 2800-3200 rpm based on compression

I tried 36* total with mine but pinged cause of high compression, so I pulled it back to 34* total.....

Set the springs so all timing was in at 3000 rpm

With my dist. and 34* total my Initial timing landed at 16*

Here's how my whole timing curve ended up.....

Initial timing 600 rpm 16*
800 RPM 22*
1000 RPM 25*
1500 RPM 27*
2000 RPM 28*
2500 RPM 29*
2800 RPM 32*
3000 RPM 34*
3400 RPM 34*


BTW... alway check timing with vac advance line unhooked and plugged