cuttyroe

Just did the whole dwell/timing thing. While doing my timing I noticed it idles much better and more low end performance with advanced timing. What would be the cons of leaving it this way and what does it mess up down the line?

71 Cutlass

I'm assuming you are talking about advancing the initial timing. Olds motors like some extra initial timing so no big deal, as long as it is not advanced too far forward causing detonation(you may have read others referring to this as "Pinging"). Do you own a timing light to know what your total timing actually is? How about a tac to know when your total timing is all in? These are helpful tools to properly "tune" your particular set up. If you do not own any of these, then simply advance your initial timing where the engine runs without "pinging" and you should not see any detrimental effects to the motor whatsoever. Also, the reason it idles better is because your rpms are higher, in which case you can adjust your idle speed mixture screws on the carb back down. Enjoy your new found "off the line" performance!

MDchanic

Advanced as far as you can while maintaining good performance and no pinging is pretty much the way to go.

Sounds like that's what you did.

- Eric

ps: where is it timed now, and what about the contributions of vacuum and centrifugal advance? Is your vacuum advance unit working?

TripDeuces

"in which case you can adjust your idle mixture screws on the carb back down"

I think you mean idle speed screw.

Idle mixture screws are a new ball game.

cuttyroe

I do have a dwell meter and I have access to a timing light. My dwell is 29.5 at 1100 and my timing I would say is around 10-12 but thats with the vac still attatched. I would like to disconnect but it looks brittle (will replace). I am saying 10-12 cause the mark is way past the plate with the numbers. No pinging and runs good. My car burns hella gas tho before and after the tune. Is there any way to get rid of the gas sloshing? Goes from 3/4 to almost empty when making fun turns.

cuttyroe

Oh yeah. I havent messed with the idle speed yet cause im not that familiar with carbs. You think I should go in?

MDchanic

I don't know. I'd never adjust one without adjusting the other, at least for a meaningful change in speed.

Change speed, adjust mixture, go back and re-adjust speed, then a quick pass to re-adjust mixture, then recheck to be sure speed is still right.

Sounds like Cutty's got to start from scratch and do a proper tune-up.

- Eric

cuttyroe

Dam. Im gonna give it a shot this weekend.

71 Cutlass

X2...adjust all screws together to make sure tune is at its best.

coltsneckbob

It was always my understanding that advancing the timing beyond the specs will lessen the life of the timing chain (chain that turns cam). It won't happen over night, but it will decrease the life span by several thousand miles.

As far as I was told the ping was created by the combustion hitting the slightly open intake........which in turn put pressure on the chain. Even if u don't hear a ping you still might be stressing the chain.

However, all that said.....in my opinion for the extra performance it is well worth a few degrees of advance.

Rickman48

I've aways set the carb with a vacuum guage, on the tube you pull the vacuum advance off of.
Kinda kills two birds with one stone, as you don't have to plug it, and you're right there!
My '69 442 pulled 23 inches, with a sight jump, until I replaced the valve springs and seals at 105k miles!

64Rocket

Disconnect the vacuum advance,
adjust idle up to 900 rpm
adjust timing to 14 to 16 *
readjust idle to 900 again
adjust timing to 14 to 16 *again

adjust idle to 600 rpm hook up vacuum advance
run rpm up to 2700 rpm and see what your total advance is.

In my opinion convert to HEI or Pertronic's ignition.
I converted to HEI and picked up power, gas mileage, drive ability.
So much easier to start.
Next will be some type of fuel injection

Gene

MDchanic

I agree, a vacuum gauge and a tach are the best way, though sound alone will do in a pinch.
I go for the straight manifold vacuum, myself, because ported vacuum from the carb disappears when the butterflies are closed, which makes it tough to adjust the idle accurately.

- Eric

1969w3155

Is there any way to get rid of the gas sloshing? Goes from 3/4 to almost empty when making fun turns.[/quote]
This is typical of the gas gauges on Olds from this era, every one that I had did that.

cuttyroe

Thanks for the replys