HELP tell me about timing - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jdfrmnt · 05-30-2009, 10:34 PM

i failed the smog check i have my timing set at 2 btd and my carb screrws out 3.5 would setting my timing at 10btd help any info would help o ya smog is due today my bad

Pont406 · 05-31-2009, 12:46 AM

What did you fail on?

jim zag · 05-31-2009, 06:41 AM

What kind pf carb? Most carbs use a starting point of 1.5 turns out. I would use 8 degrees BTDC as a starting point for base timing.

68C15 · 05-31-2009, 07:07 AM

Quote:

Originally Posted by Pont406

What did you fail on?

very good question. give us the results so we can tell you what to do. we also need to know your setup ie; carb, cam, heads etc.

capev86 · 05-31-2009, 10:46 AM

i think it is supposed to be more like 8 degrees before top dead center. i set the 307 in my 72 burb to that and it runs awesome. i also converted to electronic ignition with a petronix ignitor kit from lmc and a new cap (better unit with brass studs) and rotor from napa. also have a set of cheap wires and ac delco plugs to go in next and hope that will iron out the last bit of bucking (already much smoother than it was). i'm thinking the 37 year old wires are past their peak and the plugs probably haven't been changed either owing to the fact that the original owners didn't drive it regularly...73,000 original miles!!!

05-30-2009, 10:34 PM	#1
jdfrmnt Registered User Join Date: Mar 2008 Location: phoenix az. Posts: 53	HELP tell me about timing i failed the smog check i have my timing set at 2 btd and my carb screrws out 3.5 would setting my timing at 10btd help any info would help o ya smog is due today my bad

05-31-2009, 12:46 AM	#2
Pont406 Registered User Join Date: Aug 2007 Location: West Hills, California Posts: 679	Re: HELP tell me about timing What did you fail on?

05-31-2009, 06:41 AM	#3
jim zag ENGINE BUILDER Join Date: Apr 2006 Location: Shortsville n.y. Posts: 344	Re: HELP tell me about timing What kind pf carb? Most carbs use a starting point of 1.5 turns out. I would use 8 degrees BTDC as a starting point for base timing. __________________ JIM ZAG

05-31-2009, 10:46 AM	#5
capev86 Registered User Join Date: May 2009 Location: Eliot, Maine Posts: 1,314	Re: HELP tell me about timing i think it is supposed to be more like 8 degrees before top dead center. i set the 307 in my 72 burb to that and it runs awesome. i also converted to electronic ignition with a petronix ignitor kit from lmc and a new cap (better unit with brass studs) and rotor from napa. also have a set of cheap wires and ac delco plugs to go in next and hope that will iron out the last bit of bucking (already much smoother than it was). i'm thinking the 37 year old wires are past their peak and the plugs probably haven't been changed either owing to the fact that the original owners didn't drive it regularly...73,000 original miles!!!



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