Timing help!!

[octanejunkie]

I set my initial at 19.5 and my timing came in at 36 total.My overall was 52.I set my carb and got 22inch vac (started at 3inch! so that part is good) Idle is 930.Drove the car and it pinged so i put a 3/32 allen wrench into the vac on my M/P dist and turned it 1/2 inch clock wise which was as far as it went ,it stopped at that point ,i drove the car and it still ping a little so i took a break because i am kinda stumped!

Pinging usually mean - pre-ignition, sometimes due to not enough octane, too hot a burn in the chamber, too much advance, all of the above. I agree with crackedback, forget the vac adv for a while, cap off the port on the carb and work with initial and mechanical advance first. Get that right. You should not ping or your motor will go bye bye sooner than it should, way sooner. Your initial advance should be between 10-14 degrees, that's 2 to 6 degrees advanced over factory, your adj vac can instructions should have told you to ultimately add as much initial and mechanical advance as possible until you ping, then retard 2 degrees until you don't ping.

IMHO, ditch the vacuum advance. It's causing you problems and is really only useful for fuel mileage at cruise.

Keep it disconnected, plug it at the carb and drive it.

You got 22" of vacuum at idle? That's seems WAY too high for a 284/484

Agreed on all counts, unless he has a zero overlap cam. 21" of vacuum at idle is high but not abnormally so, it is in the "normal" range. Most of us are used to seeing much less vacuum at idle

Hi crackedback,it was all going so well,I had the manifold vac up, i could start off on a hill with little effort it sounded good,then i got out on the road and started going thru the gears and it started pinging!After that i shut the car off and turned the vac adv on the dist. clockwise 1/2 inch (2degrees?) and it bottomed out .What does that mean?Should i adjust it the orther way and try that.

You must have the Comp Cams adj vac kit, turning it clockwise zero or bottoms out the can, not sure 1/2 inch turn, which seems about 1/8th of a turn, does too much. The can "zero'd-out" is as good as disconnected

 

[clutch]

Octane , the pinging i am talking about is very minimal.I am gonna take your and crackbacks advise and just cap off the vac advance .Even with a 509 cam i know i can get it tuned just about perfect.It just takes time and trying alot of different settings to get these things tuned just right. This spring i am gonna probably go to the FBO system.

 

[octanejunkie]

Octane , the pinging i am talking about is very minimal.I am gonna take your and crackbacks advise and just cap off the vac advance .Even with a 509 cam i know i can get it tuned just about perfect.It just takes time and trying alot of different settings to get these things tuned just right. This spring i am gonna probably go to the FBO system.

Even minimal pinging is bad, obviously detonation is super bad, but neither are desirable

Set your initial timing around 10 degrees advanced, my opinion, and plot your mechanical advance curve - find out how much advance you are getting and when you are all in by

You will need a timing light, either dial back or static light with a timing tab on your balancer, and a tach. Start at 1000 RPM and go up in 250 increments documenting your advance. Optimally you should be at about 34 degrees all in by 2500 to 3000 RPM.

Plan on changing springs and weights on your distributor to tune it (at least on a chevy that's what we do.) Here is a good article on timing in general, again, from a chevy perspective, sorry I'm new to this mopar stuff