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Old 02-26-2003, 05:39 PM   #1
jkvette719
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Timing 350?

I did do a search but i didnt see anything but stock numbers. I have a 78 350 Compcams 268H its a mild cam. Performer RPM heads. Just wondering where i should set the timing for best performance. Thanks Justin
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Old 02-26-2003, 05:44 PM   #2
PHOENIX
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I think most guys run their timing at 10 Degrees BTDC (4 is stock, atleast on mine).
My engine seems to run best at 10 degrees BTDC (but my engine is stock).
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Old 02-26-2003, 06:02 PM   #3
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I agree with Eddie. Start at about 10 BTDC and drive it a few days to see what it feels like ander varied conditions. Then if you want to you can bump it up a couple degrees to see if it hurts or helps the preformance.
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Old 02-26-2003, 06:53 PM   #4
jkvette719
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Okay I did that, Thanks now I have and accel dist w/ adj. vacum advance. How do I set that? Thanks

And man I got a valve to tight or something cause it has a surge to it.
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Old 02-26-2003, 09:26 PM   #5
GMC Jim
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GM Tune up Spec Manual SD-100 has following 350 cu. in. light duty-emissions engine timing specs:-
Idle speed auto trans. 500 RPM, Ignition timing @ 8 degrees BTDC. At 2000 RPM; centrifigal advance at 12-16 degrees ( with vac advance hose disconnected and plugged). Total advance including vac advance @ 2000 RPM should be 28-36 degrees....

I use an adjustable timing lite.... Set the lite at 30-34 degrees and read the "0" mark on the crank damper/ pointer....use an accurate tachometer and have a friend hold the engine speed at 2000 RPM.
On my truck (402 engine) the vacumm advance unit was not functioning properly ; replaced it before the 2000 RPM timing specs and made quiet a difference in gas mileage and engine power.
Note that the range for the final 2000 RPM timing is 28-36 degrees....I would suggest you set it about 30-34 .... depending on gas octane you are using and other factors; adjust the timing toward the high end of the specs... but... before any detonation ( ping) is evident....
Hope this helps..........Jim
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Old 02-27-2003, 02:05 AM   #6
jkvette719
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Imnot getting any advance,,,,,but mine is adjustable so maybe i have to play with it. Thanks a ton...man at 500 RPM that feels like someones trying to tip the truck over lol...we go atleast 600. Thanks again
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