Timing and Spark Plug Gap for 350

ChrisM · 10-31-2007, 10:23 AM

Hello all,
I recently converted the 350 engine in my '73 Delta 88 to a Pertronix electronic ignition. I need to set the timing and my repair manual says to see a sticker in the engine compartment, but the owner before me had removed all stickers in a repaint effort. Does anyone know what the proper timing setting is for my car? Also, I want to put a new set of spark plugs in, but I don't know what the gap should be set at?

Thank you all in advance,
Chris

J-(Chicago) · 10-31-2007, 03:06 PM

I believe it is 17 or 18 degrees below top dead center @1100

gap for a 307 is.060
I would think they are the same.

I'd go with that on ACDelcos
If you're using Champions id go .040

88 coupe · 10-31-2007, 06:00 PM

Use of Pertronix trigger, in place of points, doesn't change the settings.

Plugs = AC R45S gapped at .035"

Timing = 12° BTDC.

Norm

J-(Chicago) · 10-31-2007, 06:15 PM

Wow, slight difference between a 1980 350 and a 1973 350.

Thanks Norm.

Oldsguy · 10-31-2007, 06:19 PM

Oh for sure! In '69 the gap was .030 and the advance was only about 8 btdc. Just shows that the engines will run well with varying settings depending upon the distributor and the junk loaded on top of the manifold for smog regs.

ChrisM · 11-01-2007, 08:41 AM

Thank you all for your help! I will try out the plugs gapped at .035 and the timing at 12 degrees BTDC tonight. This is all very new to me, and I am bumping my way around this car. Thanks again.
Chris

J-(Chicago) · 11-01-2007, 03:37 PM

Quote:

Originally Posted by Oldsguy

Oh Just shows that the engines will run well with varying settings depending upon the distributor and the junk loaded on top of the manifold for smog regs.

So do you have to compensate if you rip all of that crap out?

88 coupe · 11-01-2007, 04:43 PM

No reason to.

That "junk/crap/etc" has nothing to do with the spark advance/plug gap, or the power output of that engine.

Might be an oversimplification, but, advance requirements are determined by cylinder pressures (compression ratios) and the plug gaps, by fuel mixtures.

Norm

J-(Chicago) · 11-01-2007, 09:01 PM

Thanks again Norm.

I appreciate your straight answering style on here.

Redog · 11-02-2007, 10:18 PM

point ign .032

HEI ign .045

When I when from points to HEI, I regapped all the plugs from .030 to .045

88 coupe · 11-03-2007, 08:23 AM

Quote:

Originally Posted by Redog

point ign .032 ........ HEI ign .045 .......

Nothing to do with the distributor.

Increase in gap was because of the change to lean mixtures that were used to meet emissions standards.

On a pre '74 factory engine, .032" or .045" will work fine. '74 and later will need .045" to run satisfactorily.

Norm

10-31-2007, 10:23 AM	#1 (permalink)
ChrisM Member Join Date: Oct 2007 Location: Garden Grove, CA Posts: 37	Timing and Spark Plug Gap for 350 Hello all, I recently converted the 350 engine in my '73 Delta 88 to a Pertronix electronic ignition. I need to set the timing and my repair manual says to see a sticker in the engine compartment, but the owner before me had removed all stickers in a repaint effort. Does anyone know what the proper timing setting is for my car? Also, I want to put a new set of spark plugs in, but I don't know what the gap should be set at? Thank you all in advance, Chris

10-31-2007, 03:06 PM	#2 (permalink)
J-(Chicago) Seasoned beater pilot. Join Date: Jan 2007 Location: Chicago Posts: 1,653	I believe it is 17 or 18 degrees below top dead center @1100 gap for a 307 is.060 I would think they are the same. I'd go with that on ACDelcos If you're using Champions id go .040 __________________ I'd rather have a numbers matching poker hand. Last edited by J-(Chicago) : 10-31-2007 at 03:55 PM.

10-31-2007, 06:15 PM	#4 (permalink)
J-(Chicago) Seasoned beater pilot. Join Date: Jan 2007 Location: Chicago Posts: 1,653	Wow, slight difference between a 1980 350 and a 1973 350. Thanks Norm. __________________ I'd rather have a numbers matching poker hand.

10-31-2007, 06:19 PM	#5 (permalink)
Oldsguy Administrator Join Date: May 2004 Location: Lees Summit MO Posts: 3,172	Oh for sure! In '69 the gap was .030 and the advance was only about 8 btdc. Just shows that the engines will run well with varying settings depending upon the distributor and the junk loaded on top of the manifold for smog regs. __________________ Dan '77 Cutlass Supreme '46 2 door

11-01-2007, 09:01 PM	#9 (permalink)
J-(Chicago) Seasoned beater pilot. Join Date: Jan 2007 Location: Chicago Posts: 1,653	Thanks again Norm. I appreciate your straight answering style on here. __________________ I'd rather have a numbers matching poker hand.

11-01-2007, 08:41 AM	#6 (permalink)
ChrisM Member Join Date: Oct 2007 Location: Garden Grove, CA Posts: 37	Thank you all for your help! I will try out the plugs gapped at .035 and the timing at 12 degrees BTDC tonight. This is all very new to me, and I am bumping my way around this car. Thanks again. Chris

11-02-2007, 10:18 PM	#10 (permalink)
Redog Alero Chapter Secretary Join Date: Aug 2006 Location: Newtown, PA Posts: 831	point ign .032 HEI ign .045 When I when from points to HEI, I regapped all the plugs from .030 to .045

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
350 spark plug gap	bonesbmx	Small Blocks	12	09-23-2007 11:12 PM
69 350 Timing Chain Questions	dcolds	Small Blocks	5	09-17-2007 03:08 PM
79 350 Olds Idle speed & Timing	aristoquack	Electrical	3	07-04-2007 11:35 AM
Spark Plug Gap	66starfire	Big Blocks	6	01-03-2007 10:31 AM
Spark Plug	<james.reinhart@detroitdie>	Electrical	1	07-24-2004 09:34 PM