NEED HELP IGNTION TIMING FIRST TIMER???????????????????!!!!!!!!!
Thread Starter
Racer
Joined: Oct 2001
Posts: 412
Likes: 0
From: Monroe North Carolina
NEED HELP IGNTION TIMING FIRST TIMER???????????????????!!!!!!!!!
Does this sound right?
<UL><LI>all these with vac disconected on a MSD HEI ignition.
<LI>10 @ idle
<LI>25 degree @ 2000.
<LI>26 @ 2500
<LI> when the vac is connected it does not kick in untill high rpms.
<LI>26 @ 2500
<LI>26@ 3000
<LI>42@ 4000
This is the first time that i have messed with the timing. What do you guys recommend?
<UL><LI>all these with vac disconected on a MSD HEI ignition.
<LI>10 @ idle
<LI>25 degree @ 2000.
<LI>26 @ 2500
<LI> when the vac is connected it does not kick in untill high rpms.
<LI>26 @ 2500
<LI>26@ 3000
<LI>42@ 4000
This is the first time that i have messed with the timing. What do you guys recommend?
Le Mans Master
Joined: Feb 1999
Posts: 6,807
Likes: 0
From: Hoosier
Cruise-In III Veteran
Re: NEED HELP IGNTION TIMING FIRST TIMER???????????????????!!!!!!!!! (Corvettelvr73)
I think your curve is too flat. Most small blocks like about 36 degrees around 2800 rpm. That's with no vacuum connected.
Use ported vacuum. It's looks like you are. You should see about 50-52 degrees with the ported vacuum.
I'd try lighter springs to bring the mechanical curve in as I said above, and let the idle advance be what it may. Most guys see 10-16 degrees at idle.
Use ported vacuum. It's looks like you are. You should see about 50-52 degrees with the ported vacuum.
I'd try lighter springs to bring the mechanical curve in as I said above, and let the idle advance be what it may. Most guys see 10-16 degrees at idle.
Race Director
Joined: Apr 2000
Posts: 11,840
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From: Galloway NJ
Re: NEED HELP IGNTION TIMING FIRST TIMER???????????????????!!!!!!!!! (biltogo)
Safety Car
Joined: Feb 1999
Posts: 3,631
Likes: 14
From: Fountain Hills AZ
Re: NEED HELP IGNTION TIMING FIRST TIMER???????????????????!!!!!!!!! (Metal Wulf)
If you're only getting 16º centrifugal, something is wrong. What is the idle rpm? If you have a high idle speed, some of the centrifugal advance may already be in, leaving less to come in later. If that is the case, your actual initial timing could be lower than you think it is. Have you checked the total without vacuum advance at a higher rpm? Is this a new distributor that hasn't been recurved? Most MSD's I've seen come out of the box with a mid-range curve and don't reach full advance until well past 3k rpm.
The 16º of vacuum advance sounds right but not the delay until 4k rpm. On a no-load engine, you should see full vacuum advance by 2k or earlier depending on manifold vacuum and the canister used. Your 42º is about 10º below where it should be. The first thing I'd do is set your timing to 36º at 4k (or wherever it stops advancing). Shut it down and restart. If the engine wants to kick back against the starter, your problem remains. If not, it's been solved.
