"Need some help in finding bes
"Need some help in finding best timing setting. My engine is a 1990 4.3. I have added Vortec heads and Edelbrock intake and 4bbl carb. With the new setup there is no manual that tells me where to set the timing. Engine was originally a 2bbl and timing spec was 1dbtdc with 86-88 octane, 6dbtdc with 89 octane. I was running it at 6deg then with reg fuel because thats where it ran the best. With the new setup I have been running it at 8deg. I set it at 8 because thats the spec for the 97-98 model vortecs. I think those engines were fuel injected and it's not really an apples to apples comparison. If I set it at 6deg now with the new setup it simply will not idle. It will idle at 8deg but it's a little rough and dies occasionally. I have adjusted idle mixture until I have nearly worn out the screws. Idle is much smoother at 10 deg and up. I ran it this morning and played with the timing some. Ran it at 10 deg and at 12 deg (a little) and ended up leaving it at 10. I am a little afraid to run it any higher for fear of detonation. I did not hear any pinging in the engine during these runs. Will the spark plugs tell the story if I have detonation before damage is done? Should I be able to hear it?
Thanks"
"Need some help in finding best timing setting. My engine is a 1990 4.3. I have added Vortec heads and Edelbrock intake and 4bbl carb. With the new setup there is no manual that tells me where to set the timing. Engine was originally a 2bbl and timing spec was 1dbtdc with 86-88 octane, 6dbtdc with 89 octane. I was running it at 6deg then with reg fuel because thats where it ran the best. With the new setup I have been running it at 8deg. I set it at 8 because thats the spec for the 97-98 model vortecs. I think those engines were fuel injected and it's not really an apples to apples comparison. If I set it at 6deg now with the new setup it simply will not idle. It will idle at 8deg but it's a little rough and dies occasionally. I have adjusted idle mixture until I have nearly worn out the screws. Idle is much smoother at 10 deg and up. I ran it this morning and played with the timing some. Ran it at 10 deg and at 12 deg (a little) and ended up leaving it at 10. I am a little afraid to run it any higher for fear of detonation. I did not hear any pinging in the engine during these runs. Will the spark plugs tell the story if I have detonation before damage is done? Should I be able to hear it?
Thanks"