timing with a vacuum guage

[peglegs]

hey folks im back on my project having put some miles on it im fine tuning it & im not satisfied.
i have a 90 v/6, now has a 500 cfm edlebrock & hei, the timing chain cover was also changed as it had a sensor port in it & present tab & damper marks at 0 with #1 on compression stroke.

present symptoms are light pinging entire rpm range & running rich @ 12*

i adjusted a/f mixture with guage to highest reading. now timing it with a vacuum guage my highest reading around 35*? (up around 12 o'clock) & hitting the manifold been running at 12*. im thinking im 1 tooth off? should it go back 1 tooth (CC) ?
ive had the craziest problems with this project i swear there's a ghost in it

[clinebarger]

Chevy? 4.3L?

Some sort of emissions era HEI? The Vacuum advance on these add way too much timing!

You need to KNOW where the timing is, Timing tape or a Better (Advance) Timing Light is a must.

500cfm AFB on a 262 CI engine, Not so much the CFM (which is too much), But the jetting is bad (rich) for most stock 350's.

[peglegs]

Originally Posted by clinebarger

Chevy? 4.3L?

Some sort of emissions era HEI? The Vacuum advance on these add way too much timing!

You need to KNOW where the timing is, Timing tape or a Better (Advance) Timing Light is a must.

500cfm AFB on a 262 CI engine, Not so much the CFM (which is too much), But the jetting is bad (rich) for most stock 350's.

aftermarket hei, yes 90 chevy is a 4.3...... probably advance light better but thats why im here i can spend money all day on suggestions dont mean to be outta line here but lookn to get my question answered. also talked to edlebrock this carb was rebuilt by them for this enginei cant argue with them. IF YOU THINK ITS WRONG then help me out telling me to change the jets does not help me what size r u suggesting please dont feed me bits im lookn for definative answers to move on thanls for responding....sincerly

[clinebarger]

Originally Posted by peglegs

aftermarket hei, yes 90 chevy is a 4.3...... probably advance light better but thats why im here i can spend money all day on suggestions dont mean to be outta line here but lookn to get my question answered. also talked to edlebrock this carb was rebuilt by them for this enginei cant argue with them. IF YOU THINK ITS WRONG then help me out telling me to change the jets does not help me what size r u suggesting please dont feed me bits im lookn for definative answers to move on thanls for responding....sincerly

If the 500 cfm is jetted correctly...Good, You didn't state that in the original post.

You don't know exactly where your Total Timing is, Or how much the Vacuum Advance is added on top?

[peglegs]

anyone familiar with using vacuum guage that could correct me? in the past few days i have read perhaps 100 threads/articles concerning timing with a vacuum guage with quotes like "many old timers will still diagnose engine problems with a vacuum guage" & "mechanics will still use a vacuum guage today to time an engine" so this is my question again

im at 12*BTC, faint pinging, running rich

WITH A VACUUM GUAGE LOOKING AT THE INCHES OF MERCURY CLIMB TO 21 AS I TURN MY DISTRIBUTER IT HITS THE MANIFOLD AT APROX 35* AT I2 OCLOCK ON THE DAMPER Am I OFF A TOOTH .

i now feel that this thread is dead, my question not answered like ive seen so many threads killed by going off on tangents not related to the guys question, or buy this or that & spend $300 on useless **** specially when the guy cant afford it, needs his ride to get to work tomorrow morning orr has to go out in the 105* heat or 10 below zero to fix it.......so sorry if i offend anyone but ive had so many stupid things happen to my build its rediculous but on the other hand not a dumass i took a 40 ih installed it on a 90 4x4, yes chevy, it rides, handles great so sorry if i ended up with freakn dumblems there are so many great mechanics here that could answer this question but shy away now that its a dead thread.

[Twisted78SS]

I had some great graphics with instructions for using a vac gauge, but can't seem to find them.
This page may help
http://www.hotrodreference.com/59/va...ng-up-engines/

[cableguy0]

Without knowing total timing the vacuum gauge does NOTHING for you at idle or at a rest other than show base timing. You need to be able to see what total timing is with vac advance. Without an advance timing light your chasing a ghost. You could have 50 or 60 degrees of advance with the vacuum advance at 3k rpm. You can get an an advance dial light relatively cheap. The vacuum gauge tells you nothing above idle. Its useful for setting base timing to an extent. The old ways are the OLD ways for a reason.

[cableguy0]

Your question was answered. You cant be a tooth off. Its not possible. The distributor doesn't know where its at. Settle down a bit. A response like your last one will stop a lot of guys from trying to help. Nobody can tell you what size jets to use. Its trial and error. Your either going lean or timing is too far advanced if its pinging. If your timing at idle was moved up to 35 degrees that massively too far advanced.

[cableguy0]

The biggest problem is that you cannot duplicate the conditions under load while sitting in the driveway using a vacuum gauge. You have to know the timing numbers.

[clinebarger]

Originally Posted by peglegs

I now feel that this thread is dead, my question not answered like ive seen so many threads killed by going off on tangents not related to the guys question, or buy this or that & spend $300 on useless **** specially when the guy cant afford it, needs his ride to get to work tomorrow morning orr has to go out in the 105* heat or 10 below zero to fix it.......so sorry if i offend anyone but ive had so many stupid things happen to my build its rediculous but on the other hand not a dumass i took a 40 ih installed it on a 90 4x4, yes chevy, it rides, handles great so sorry if i ended up with freakn dumblems there are so many great mechanics here that could answer this question but shy away now that its a dead thread.

Good luck to you, Hopefully one of those Great Mechanics will be here shortly to give the free miracle cure you want.

[crazy longhorn]

I just plug in a different 'pill', to change the timing on my truck? Distributor....whats that? All joking aside, my grandfather , many times used that old vac guage as a tool....but he set the timing by ear ! Understand that in his day, the old cars were a tad different....he would be around 108 yrs old (if he were still here today)! With all the advances in modern day stuff, you can still use that vac guage as a tool for diagnostic purposes, such as checking for leaky valves/ loose guides/bad springs/ head gaskets ,ect. But you absolutely can not use it to set the timing! On the cheap, if you can find the proper balance tape....wrap it, & use any standard lite, to check initial/total + vac advance. Other than that, I will use the wooden stick at the base of my ear, like grandma showed me.....nevermind, she was showing me how to check for buffalo longhorn