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Timing for 1988 OMC 5.0 2 barrel carb

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svendaawg

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Need Timing Specs for my 1988 OMC Cobra.
I have the manuals for 1987 and 1989 OMC but not one for my particular motor which is 1988 OMC Cobra 5.0, 2 barrel carb Engine # 502APRGDP. Each manual differs in the timing specs for the 5.0 and neither gives the spec for 2 barrel carb (no sure it matters) One manual 86 or higher octane at 10 degrees BTDC . The other manual specs 5 degrees BTDC for 86 octane and 10 degrees BTDC for 89 octane. I typically run the standard unleaded 87 octane. am I over thinking this. Should I set the time at 10 degrees BTDC.
 
The 5 or 10 degrees BTDC refers to the BASE or Initial timing.
We fire up on and we idle on BASE advance, and that's it.

More importantly will be what the Progressive and Total Advance are doing.


With the standard GM SBC build (GM style Full Dished pistons), you will want to see no more than 28* @ 3,200 RPM.
The progressive advance will be rather linear.
More than that may cause a very destructive Ignition Induced Detonation.

You could bump this up a tad bit if you used a higher octane rated gasoline.
 
RicardoMarine said:
The 5 or 10 degrees BTDC refers to the BASE or Initial timing.
We fire up on and we idle on BASE advance, and that's it.

More importantly will be what the Progressive and Total Advance are doing.


With the standard GM SBC build (GM style Full Dished pistons), you will want to see no more than 28* @ 3,200 RPM.
The progressive advance will be rather linear.
More than that may cause a very destructive Ignition Induced Detonation.

You could bump this up a tad bit if you used a higher octane rated gasoline.
Click to expand...

Thank you for the response.
Time you go out and buy a new timing light with advance.
 
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