Timing Advance In Too Fast
Thread Starter
Drifting
Joined: Feb 2005
Posts: 1,583
Likes: 5
From: Richardson Tx.
Timing Advance In Too Fast
I have been following all of the papers from Lars and Barry on setting timing on my '79 HEI. I recently switched over to Vortec heads (w/ mild GM Cam) and just shimmed up the disti -- and replaced the springs with Mr. Gasket Part # 928G using the Gold springs per Lars.
With advance can plugged and hose plugged, I set my total timing to 32 degrees to start with on my adj. timing light. I then checked to see where all of my advance is coming in at. This is 1600 RPM every time.
I am not getting any audible detonation.
Is this unusual in that it is coming in too fast? any ramifications to this?
With advance can plugged and hose plugged, I set my total timing to 32 degrees to start with on my adj. timing light. I then checked to see where all of my advance is coming in at. This is 1600 RPM every time.
I am not getting any audible detonation.
Is this unusual in that it is coming in too fast? any ramifications to this?
Burning Brakes
Joined: Aug 2002
Posts: 1,146
Likes: 10
From: Scottsboro Alabama
It appears the gold springs are the lightest thus the fast timing curve. You can slow it down by using one light with a medium spring. You can mix and match the different weight springs in order to achieve how fast the curve occurs, you just have to experiment.
Pro
Joined: Aug 2001
Posts: 683
Likes: 0
From: mississauga ON
Originally Posted by 79vetter
I have been following all of the papers from Lars and Barry on setting timing on my '79 HEI. I recently switched over to Vortec heads (w/ mild GM Cam) and just shimmed up the disti -- and replaced the springs with Mr. Gasket Part # 928G using the Gold springs per Lars.
With advance can plugged and hose plugged, I set my total timing to 32 degrees to start with on my adj. timing light. I then checked to see where all of my advance is coming in at. This is 1600 RPM every time.
I am not getting any audible detonation.
Is this unusual in that it is coming in too fast? any ramifications to this?
With advance can plugged and hose plugged, I set my total timing to 32 degrees to start with on my adj. timing light. I then checked to see where all of my advance is coming in at. This is 1600 RPM every time.
I am not getting any audible detonation.
Is this unusual in that it is coming in too fast? any ramifications to this?
The Mr. Gasket HEI curve kit is 929g not 928g. I think the
kit you bought is for points type distributors (which would
have different springs).
Thread Starter
Drifting
Joined: Feb 2005
Posts: 1,583
Likes: 5
From: Richardson Tx.
Originally Posted by LT4Coupe
Actually it's not so unusual. I think you bought the wrong kit.
The Mr. Gasket HEI curve kit is 929g not 928g. I think the
kit you bought is for points type distributors (which would
have different springs).
The Mr. Gasket HEI curve kit is 929g not 928g. I think the
kit you bought is for points type distributors (which would
have different springs).
If I recall it was pegging out before 1800 with the 929s as well.
Is there such a thing as having it come in too early with a negative impact?
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,392
From: At my Bar drinking and wrenching in Lafayette Colorado
The 928G kit is correct - using the gold springs usually produces very good results, but you can try installing one black and one gold spring and see what it does - the black spring, although softer, is just a tad shorter, and may pull the curve back a tad. The curve is only too quick if you're getting detonation. If you have the stock compression ratio, you can bring in a very quick curve with good results. If the car feels good and does not knock, you're good to go.
Thread Starter
Drifting
Joined: Feb 2005
Posts: 1,583
Likes: 5
From: Richardson Tx.
I decided to pull off the gold springs and go with the ones that felt the firmest to the stretch- the silver ones. Full advance is all in by 1800 RPM and initial timing is at 20. With the gold springs I had 22 initial and full in by about the same.
Not sure what to make of these results.
I am not using the Mr. Gasket weights but could my existing weights be causing it to come in so soon?
Not sure what to make of these results.
I am not using the Mr. Gasket weights but could my existing weights be causing it to come in so soon?
Last edited by 79vetter; Nov 25, 2006 at 06:03 PM.
Burning Brakes
Joined: Jun 2002
Posts: 837
Likes: 3
From: Texas
I E-mailed Mr. Gasket about which springs are which in the 928 kit since there's nothing on the package.
The reply I got was that gold was heavy, silver was medium, and black lightest. Black are obviously the light springs.... what concerned me was that (using digital calipers) gold and silver have exactly the same coil length and wire diameter. So.....different types of material??
The reply I got was that gold was heavy, silver was medium, and black lightest. Black are obviously the light springs.... what concerned me was that (using digital calipers) gold and silver have exactly the same coil length and wire diameter. So.....different types of material??
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Originally Posted by goinbroke
gold and silver have exactly the same coil length and wire diameter.??
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Burning Brakes
Joined: Jun 2002
Posts: 837
Likes: 3
From: Texas
Originally Posted by jackson
Do they both have the same number of coils? Are the coils themselves same diameter?
Last edited by goinbroke; Nov 25, 2006 at 06:35 PM.
Thread Starter
Drifting
Joined: Feb 2005
Posts: 1,583
Likes: 5
From: Richardson Tx.
The gold seemed to be the heaviest to me but I decided to try the silver ones to experiment. There really wasn't much difference. I am wondering if the weights that I have are not original.
I would really like to have the advance come in later to see how it feels. My new rebuild feels "slow" to me. Any advice is appreciated.
I would really like to have the advance come in later to see how it feels. My new rebuild feels "slow" to me. Any advice is appreciated.
