Everyone has said, you should be more concerned about your cars total timing than it's initial timing. Like you don't want your car at 2%btdc at idle, because your are wasting power. Well, my car idles at 19%btdc with the distributer advance disconnected. SO, I figured my car would be detonating at 3000-3500 rpm's. SO, I checked the timing at 3000,3500, &4000 rpms and my total timing was about 35%btdc. That is about where I want the timing at this rpm, right???? Why is it everyone else is at about 8-12% btdc at idle to achieve this 34-36% at 3000-3500 rpms. ANd, is this a bad thing. Is my car some freak of nature, or is anyone else out there experiencing this??? Thanks

 

anyone?????????????

 

you checking it with the est unplugged? if you set the base at 19* and have a total of 35* it soulds like you aren't getting enough advance. you have any knock counts?

 

I heard that if you go over 38%btdc that you risk detonation on a 350. Knock counts????

 

Not sure of what kind of distributor your running, but I assume you have a late model HEI pre 80's.

Your initial looks a bit high for an HEI (mechanical advance wise), so you need to double check that your timing the initial below 1000rpm's, maybe even closer to 800rpms or so. If you have very loose springs, they'll what to open up very very quick.
It's hard to believe a stock HEI only has a 16 degree curve length (mechanical advance wise). Usually there - what about 24+

You'll want to shoot for 36-38 total, and what ever your initial ends up on. There not to much you can do with a stock unit. With an aftermarket distributor, you can adjust that with stop bushings.

You initial isn't to out there. I'm running 17 initial / 38 total right now. That's a 21 degree curve length (Yeap a 21 degree stop bushing. Me likey my MSD billet distributors.)

BTW: I used a 21 bushing to set my initial up there (not to high, it becomes hard to start) because it gives you more initial torque.
Theres a science to all the madness
If your really into it, pick up a book called, Optimizing your Ignition by. Chris Jacobs. Yeap, Jacobs ignitions himself is a PHD. Who knew?
No easy answers in that book - though.

Ron

 

BTW: If thats your garage that you get to work on your car and park it, I'm going to be pissed !!!

I'm thinking about building a 4 bay garage/shop on my land, cause this damn parking garage attached to my house is just that, a parking garage!!!

Yea, going above 38 is pushing it. However Altitude & octane alows you to get away with a little more by slowing the burn down.
Don't play with that to much, cause you might need to run Hi octane to obtain 38. It depends on a lot factors, but 36 is usualy safe. 38 if you can.

 

Try slowing the idle rpm down as low as it will go when checking initial timing. If someone installed a "curve kit" in the distributor
{lighter advance springs} then they tend to start advanceing at
a speed near idle. You'll have to determine what total timing
your motor prefers. It will be between 30 and 36 degs if your balancer timing marks are correct.

You determine the best total timing by makeing test runs at the drags and watch your MPH at the end of the quarter, wqhile trying different settings. You ET is a bad indication because it will vary too much for other reasons.
If your carburation is lean, your motor will tend to want more timing than it should have so you have to correct the A/F-R
too. Then often your motor doesn't need quite so much timing.

 

ronterry
No, that's not my garage, but I do have one. Mine is not nearly that big, but hey it's big enough to pull my car in out of the rain or sun and get to work on it. I live in military housing, so I am really lucky to have a garage at all. That is the main reason I wanted to move here. But shhh, don't tell my wife, she bitches every time she sees me heading towards "that dam car" as she calls it. When I checked my initial timing, My car was idling at about 750 rpm's. When checking your cars total timing, it shouldn't matter if your vacuum line is attached or not, since you get no vacuum at that high rpm anyway right???? I think I will turn it up just a little, and see how she runs. Maybe that 3 degrees will unleash the beast. This **** gets any more powerful and my *** will be in jail.. Then my wife can say, it because of "that dam car" LOL!!!!!!!! Thanks for all the responses.

 

Actually it does make a difference. You want to disconnect it when checking total timing. You'll have no vacuum at WOT, I mean the flaps fully open, and I hope to hell & back your not checking your total that way
I forgot to do that the other day, and my total was off the scale. I was like WTF? -doh - pulled the vacuum advance hose - there she is

That's all you can do with total is, tweak-test-tweak-test...

...and later you can even tweak with the vacuum advance for better mileage haaaaaaaaa....


Ron

 

BTW: Back when I was a dependant, I used to use the **** out of the base garage. They had some tooooools, and the old guys there would love to help work on your car.

Man I miss that, but the Air Force has this thing where you can't be a dependant at 33. I think I lost it when I turned 23 so it's been ten years, man I even miss the liquor store prices.


Ron

 

I havn't adjusted the timing, I was just checking it because the guy who built my car had my distributer advance hooked up to the full vacuum instead of the port vacuum. Can you imagine what my idle timing was. When I checked my total, I just left the vacuum line hooked up, because I heard people say it didn't matter since there is no vacuum there at that kind of rpms. JUst a safety in case there is somethin wrong and you do have. I will check it tomorrow with the line connected and disconected.

 

Dam ron, looked at your sig, how many d*m cars do you have. What kind of job do you have, because I need in that field. ALmost one car for every day of the week.

 

RealEstate

The Vette will be paid off in 10 payments. Allmost there!!!
The ****ing Impala, I'll be paying till 2006 or something

All you need is some decent credit, and you to can own lots of cars

The '82 is my racecar, thats been totaly stripped. But turns heads in public. You should see the faces when I pop off the steering wheel to get out of the car. It's priceless...

The '81 is going to be restored, as soon as I find some funds to build a garage. Were talking about a long term project, and lots of money.

I would still love to own a '69 GTO...

Ron

 

sorry to jump in but im just realizing the benefits of playing with timing...i have hei with springs and vacuum advance and for 1 year my vacuum advance diaphram was broken and leaking, causeing all kinds of problems and bad gas mileage..i found it and fixed it and now she is starting to come alive. i have bought 2 advance curve kits..spectre in the shiney isle at pep boys..and mr. gasket which looks a lil nicer..ok with the lightest springs from either kit, with vacuum advance capped i only get 12-15 additional advance from base timing...i used to set my timing around 6-8 cause thats where i heard it should be.. now i kept it at 10-12 and have experimented with 14......car didnt ping.. still feels like it could be peppy'r.. even at 14, with mechanical advance kicked in im getting mabye 29-30??? now my new vacuum advance module/diaphram is pulling it mabye 25 degrees....what im asking is,is there a better curve kit to give me more? shouldnt my mechanical pull harder than my vacuum? and when you say 36 total that is not 36 more than your base timing but 36 from zero?