Is it possible for the groove to be in the wrong place?
Initial Timing Problem
Thread Starter
Safety Car
Joined: Oct 2004
Posts: 3,725
Likes: 5
From: Minnesota
Initial Timing Problem
I finally got my new 350 HO installed and started it. 
The initial timing is supposed to be 10 degrees but it won't run with less than about 15 and better at around 20. I have to guess since the indicator only goes to 12. What's the problem here. Thanks.
The initial timing is supposed to be 10 degrees but it won't run with less than about 15 and better at around 20. I have to guess since the indicator only goes to 12. What's the problem here. Thanks.
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
what makes you think there is a problem? i tried getting my new 350/350 to run at 8* because thats what the Haynes manual says for a 77 and it didn't like that at all...turns out my new engine had nothing similar to the original L48, and 8* was not enough for my new engine..... i think i'm at either 14* or 16* and the car runs great.....so i would reexamine the spec and try and determine why they gave you that ......
Tech Contributor
Joined: Aug 1999
Posts: 14,356
Likes: 6,328
From: At my Bar drinking and wrenching in Lafayette Colorado
There's no problem. Set the car up for 36 total timing. That should bring your initial up into the 16-20 degree range. 18 initial is optimum for a performance engine. The 10-degree spec is published for an engine that needs to pass emissions, and will not work well for a performance application. Set it up for total timing ad just verify that this gives you at least 16 initial. More is usually better (I run 24 on mine).
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Tech Contributor
Joined: Aug 1999
Posts: 14,356
Likes: 6,328
From: At my Bar drinking and wrenching in Lafayette Colorado
Originally Posted by CGGorman
What other symtoms come of too-low initial timing? No start/hard start, rough idle, run-on, etc.?
Drifting
Joined: Sep 2004
Posts: 1,532
Likes: 4
From: Fairview Heights Illinois, near Saint Louis MO, STL C3 Shark
Originally Posted by bobs77vet
what makes you think there is a problem? i tried getting my new 350/350 to run at 8* because thats what the Haynes manual says for a 77 and it didn't like that at all...turns out my new engine had nothing similar to the original L48, and 8* was not enough for my new engine..... i think i'm at either 14* or 16* and the car runs great.....so i would reexamine the spec and try and determine why they gave you that ......
How do you set timing with a vacuum gauge? Im planning on doing it this way this spring.
Tech Contributor
Joined: Aug 1999
Posts: 14,356
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From: At my Bar drinking and wrenching in Lafayette Colorado
Originally Posted by ruby76
How do you set timing with a vacuum gauge? Im planning on doing it this way this spring.
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by lars
There's no problem. Set the car up for 36 total timing. That should bring your initial up into the 16-20 degree range. 18 initial is optimum for a performance engine. The 10-degree spec is published for an engine that needs to pass emissions, and will not work well for a performance application. Set it up for total timing ad just verify that this gives you at least 16 initial. More is usually better (I run 24 on mine).
Lars thanks again for taking the time to help us out i can tell you we all really appreciate....thks bob
Burning Brakes
Joined: Nov 2004
Posts: 1,028
Likes: 0
From: San Antonio Texas
Originally Posted by lars
There's no problem. Set the car up for 36 total timing. That should bring your initial up into the 16-20 degree range. 18 initial is optimum for a performance engine. The 10-degree spec is published for an engine that needs to pass emissions, and will not work well for a performance application. Set it up for total timing ad just verify that this gives you at least 16 initial. More is usually better (I run 24 on mine).
24 initial, really lars???? so do you then only have 12 mechanical to get to the 36. do you have any hot start problems with that much initial timing???
Safety Car
Joined: Oct 2004
Posts: 3,920
Likes: 731
From: Youngstown Ohio
Originally Posted by jdmick
I finally got my new 350 HO installed and started it. The initial timing is supposed to be 10 degrees but it won't run with less than about 15 and better at around 20. I have to guess since the indicator only goes to 12. What's the problem here. Thanks.
The initial timing is supposed to be 10 degrees but it won't run with less than about 15 and better at around 20. I have to guess since the indicator only goes to 12. What's the problem here. Thanks.
Melting Slicks
Joined: Feb 2003
Posts: 2,330
Likes: 6
From: Long Island NY
I'm sooo glad other guys have the same timing as me. I followed Lars method and also used his advance kit and my initial is about 22* with 36 & 52. I thought it was high but the cars runs fine. Now I know I'm Ok... 
Tech Contributor
Joined: Aug 1999
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From: At my Bar drinking and wrenching in Lafayette Colorado
Originally Posted by greyghost79
24 initial, really lars???? so do you then only have 12 mechanical to get to the 36. do you have any hot start problems with that much initial timing???
Since I do things with my own car that I wouldn't recommend as a general practice to other people, I conservatively recommend 18 degrees as a very good initial timing setting with an 18-degree centrifugal advance curve for 36 total. This will almost always perform exceptionally well in any performance engine, and is a solid baseline from which to start tuning.
redc3: Step by step instructions are published in my tech papers posted on Forums all over the Internet. If you want a clean, up-to-date copy in MSWord format, drop me an e-mail request to:
V8FastCars@msn.com
