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1981 timing

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Old Mar 9, 2016 | 08:03 PM
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Default 1981 timing

Emission sticker and service manual call for 6 degrees. btdc. Is there a better setting? All stock and emission crap still hooked up.
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Old Mar 9, 2016 | 08:25 PM
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Originally Posted by 2tone81
Emission sticker and service manual call for 6 degrees. btdc. Is there a better setting? All stock and emission crap still hooked up.

You can get a slight gain in power by advancing it a bit but at the expense of a dirtier exhaust.
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Old Mar 9, 2016 | 09:17 PM
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set it to 10* and it will run a lot better.
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Old Mar 9, 2016 | 09:25 PM
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Originally Posted by 2tone81
Emission sticker and service manual call for 6 degrees. btdc. Is there a better setting? All stock and emission crap still hooked up.
I got away with 12 btdc on mine....... throttle response was great!!!!!
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Old Mar 9, 2016 | 09:40 PM
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Like any other small block chevy you can set up the ignition curve to provide about 35 degrees of total advance, all in by about 3000 rpm. The vacuum advance should give you another r16 or 18 degrees of advance. Those smog motors in the late 70's and early 80's were set up to run so lean you may run into detonation problems if you advance the timing unless you take steps to richen up the mixture.
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Old Mar 10, 2016 | 02:03 AM
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Default Vacuum Gauge

[QUOTE=2tone81;1591737000]Emission sticker and service manual call for 6 degrees. btdc. Is there a better setting? All stock and emission crap still hooked up.[/QUOTE

No matter how stock the engine will be there will always be differences between all engines. even two fresh engines out of the factory. because of tolerances that are allowed on mass produced engine. usually the best way to go is hooking up a vacuum gauge up to either a manifold, or carburetor base vacuum line. that way the engine will tell you what it wants for timing based on the max vacuum possible. start at the 6 degree mark and move the distributor around once you find max vacuum i usually retard the distributor 1 or 2 degrees.
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Old Mar 10, 2016 | 03:09 AM
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12 degrees on mine too. she runs really well.
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Old Mar 10, 2016 | 07:00 AM
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There is no vacuum advance on an '81 if all computer controlled hardware is installed and working...Good Luck!
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Old Mar 10, 2016 | 11:54 AM
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If it's bone stock I would follow what is in the specs. However you might add 2-4 degs to help it out.

Last edited by MotorHead; Mar 10, 2016 at 11:54 AM.
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