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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: markzepp820 on March 26, 2007, 01:56:00 am

Title: timing without gun...
Post by: markzepp820 on March 26, 2007, 01:56:00 am

I was wondering if anyone has ever set their ignition timing without using a timing light. I have a 1979 Chevy P/U with a 350 and HEI. A couple years ago my cousin had played with the timing by ear. He would play with the dizzy while idling and and rev the motor. Man...it ran awsome after he played with it. I've been playing with my timing to get my 350 running its best. With my engine at idle, I would turn the dizzy until I got the highest idle speed...and I would rev it to get the best throttle response. Does this sound right to anyone? I really don't know everything about ignition timing. I know the best way is to use a timing light...ain't got the money right now...

thanks,
Mark

Title: Re: timing without gun...
Post by: warlok1469 on March 26, 2007, 03:59:00 am

Everytime I time it with a light, it runs the worst!!  I advance it till it spark knocks at full throttle, then back it off  till it stops and shuts down without dieseling. If it has a hard time starting, I retard till it starts right up.
Basically, advance as far as possible where it starts right up, shuts down good, and doesn't spark knock.

If you kill a man, you're a murderer.....kill many, and you're a conquerer..... kill them all,..... YOU'RE A God!!

Title: Re: timing without gun...
Post by: Lt.Del on March 26, 2007, 10:21:00 am

I never use a light.  Turn the distributor slightly counter clockwise (advancing spark) and run it.

Do this in small increments.  Eventually you will hear it pinging or valves rattling under load or up hill.

At this point, turn distr. slightly clockwise in very small increments (retarding the spark).  I do this until when i run it hard it no longer pings and rattles.  This is where  i like mine.

just my $.02 worth

SgtDel
aka "Andy"

www.delbridge.net

1979 Big 10 383 stroker
1991 Blu 'Burb 3/4 ton 4x4

Edited by: SgtDel  at: 3/26/07 9:24 am

Title: thankyou
Post by: markzepp820 on March 27, 2007, 12:52:00 am

awsome, thankyou guys. I'm gonna play with it some more tommorow.

                      Mark

Title: Re: thankyou
Post by: roundedline on March 27, 2007, 10:55:00 am

I usually time/tune mine with a Vacuum gauge on stock motors...

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

Title: Re: thankyou
Post by: markzepp820 on March 28, 2007, 12:27:00 am

I heard of people using a vaccum gauge to get the highest vacuum reading, then to take it down 2 notches. For example, highest vacuum 18hg then take it to 16 and it should be very close, at least thats what this one guy said.  
                              thanks again everyone,
                                                         mark

Title: Re: thankyou
Post by: SUX2BU99 on April 03, 2007, 02:04:00 pm

I tuned mine the same way, without a light. Even though I'm at sea level, where air is the most dense and makes motors the most likely to detonate (knock or ping), my 350 must be wicked low compression because even on 87 octane gas I advanced mine so far it started to drop off noticeably in power and still no detonation!  So I backed it off until the power and throttle response came back.  As for the high idle, I then adjusted the idle speed screw on my carb to bring it back down to about 750 in park.

Title: Re: thankyou
Post by: VileZambonie on April 03, 2007, 07:31:00 pm

General rule of thumb for most stock and close to stock applications, don't run over 38°s of total advance. A timing light is an effective and essential tool for anyone who works on their engine.

Title: Re: thankyou
Post by: joesgarage71 on April 04, 2007, 08:26:00 pm

I used a vacuum gauge and timed old rusty and then used the dial timing light and turned the dial till it came to zero on the balancer, looked at the dial and it was at 37degs