307 non computer controlled timing.

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Jimmy

Greasemonkey
Jan 25, 2016
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Gulfport, MS
What should the timing be on a 307 olds after swapping to HEI distributor? I made the swap a couple of months ago but still think I may have a timing issue.
 

DoubleV

Royal Smart Person
Feb 25, 2011
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Medina Ohio
No. Initial timing can't be set unless you know the advance curve of the new distributor you put in. Most Olds engines with HEI's we're set at 20 which is the same as the computer controlled HEI's.
 

DoubleV

Royal Smart Person
Feb 25, 2011
2,156
406
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Medina Ohio
A stock 307 should like around 36-38 total. I would shorten the curve so you can run 20 initial and still get 36-38 total. For now, I'd run 16-18 initial.

When is all of your 20 in by? What about vacuum advance? How much? You running an egr valve?
 
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Jimmy

Greasemonkey
Jan 25, 2016
216
469
63
Gulfport, MS
A stock 307 should like around 36-38 total. I would shorten the curve so you can run 20 initial and still get 36-38 total. For now, I'd run 16-18 initial.

When is all of your 20 in by? What about vacuum advance? How much? You running an egr valve?
approximately 1800 rpm is when total is in. Vacuum advance is 10deg and no EGR valve.
 

TURNA

Rocket Powered Basset Hound
Jul 24, 2009
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Did you swap the carb too?
 
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Oct 14, 2008
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Melville,Saskatchewan
Add more vacuum advance, about double. The 18 base should be about right, I find low compression Olds V8's love a lot of timing part throttle especially.
 
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pontiacgp

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Mar 31, 2006
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With no egr you'll have to back off the timing a coupld of degrees. The egr cools the combustion chanber and without that cooling the advanced timing can cause pre-ignition due to the heat.
 
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