JustinHoMi All American 761 Posts user info edit post |
I'm trying to set the ignition timing on a chevy 307ci engine. What does the timing mark look like? I don't really see any distinct mark on the harmonic balancer, except for a miniscule white dot. It's a lot easier to read on other cars... and unfortunately the shop manual doesn't say....
Also, any idea as to exactly what the timing should be? My shop manual is for a 64 bel air, but the engine is out of a 68. I think the 283 is 4 or 5 deg. 11/27/2005 2:26:26 PM |
optmusprimer All American 30318 Posts user info edit post |
set it as high as it will go and still start/drive without spark knock, then back it off a hair. 11/27/2005 9:36:32 PM |
zxappeal All American 26824 Posts user info edit post |
5 degrees is a good place to start...then what Joel said. Increase it in 2-degree increments until it starts pinging, then back off 2 degrees. You'll get your best performance there.
Fuck what the book says here. Too many variables, including lower octane fuel available now. 11/27/2005 9:38:30 PM |
69 Suspended 15861 Posts user info edit post |
what year is it and is it hei, carbd or tbi? clean the damper good with some sandpaper and there should be a long line with several short lines after it. if it is a stock damper, every intermediate line should be 3 degrees. mark every line with paint, then set it around 5 degrees, depending on your cam and the fuel you run in it. then like optmus said, keep bumping it up until you get a knock at high load, and back it off about 2-3 degrees 11/27/2005 9:57:33 PM |
optmusprimer All American 30318 Posts user info edit post |
[Edited on November 27, 2005 at 10:13 PM. Reason : who cares]
11/27/2005 10:03:14 PM |
JustinHoMi All American 761 Posts user info edit post |
I can see the lines that are visible w/o the timing light, but I can't see the line/dot that the timing light reveals.
In all honesty, I'm not 100% sure what knocking/pinging sounds like. I've always had cars that would handle any advance I gave it. If it sounds like what I imagine a "ping" would sound like (something more high pitched), then I'm fine. But if it sounds more like a knock... then I'm getting it. The engine makes a sound that I can feel more than I can hear. It's a low pitched sound that doesn't come in any sort of rhythm. It seems like I get the sound no matter how high or low I set the timing. It doesn't happen while it's idling, or when I rev the engine up while in park. It just happens when I get above 10-15mph... I'm scared to go any faster .
I just rebuilt the carb, so I may just need to adjust it. 11/27/2005 10:25:23 PM |
69 Suspended 15861 Posts user info edit post |
it will actually be a ticking sound, and if the carb is jetted right on the mains, then all you need to do is set your idle speed, turn each idle jet in and out until the engine runs rough, set it halfway in between and repeat a few times. if it floods off idle, lean them out a little, or use a smaller accelerator jet, and if it starves, set em a little rich, and try turning the distributor as far back as you can and keep the engine running, then slowly increase it till the knock comes back. fuck a timing light. 11/27/2005 10:36:05 PM |