quick sbc timeing question

tomorrow i will drop in my new distributor from bubba here on the h.a.m.b my question is where should i run the timeing to start with i know how to get number one up to top. i want to know what degree btc or atc ...thanks..

 

Start at 6-8 deg. BTDC can't hurt anything that way ................................

 

I always start about 10 degrees btdc on the balancer mark to start it, (verify that the marks are correct,don't ***ume), then fine tune based on gas quality.
Take into consideration for the mechanical, the weights in the distributor and the vaccuum advance all should collectively add up to around 30 degrees. Each engine is different and it's timing needs will vary.

 

i was reading on a search to satr at 4 btdc than work from there im shure 6 is fine also thanks....

 

12 is where i set my base timing. i tried 8 and 10, and it just wasnt enough. they will vary quite a bit on what is required. when i was reading others timing woes, some even needed base of as much as 16. i think the total advance is the most important...mine is right around 32.

 

thanks!!!

 

With the timing mark at TDC, on a SBC I aways try to drop the distributor in the hole with number one lined up to fire and equal room to swing the vacuum can ahead or behind without whacking the intake manifold, firewall, or any other obstruction. After the ****** fires, I swing the distributor to advance it to where I think it needs to be for that motor. Unless the damper ring has slipped or somebody got the cam gear installed a tooth off, I have found 6 to 10 degrees BTCD usually gets you close enough to go around the block. Never hurts to pull #1 spark plug first and crank it around with a finger closing the hole to verify you are on the compression stroke and not 180 out either.

 

You need to ask bubba. He set's your advance to provide one number at idle, another all in at **** rpm. You need to know those or you are just guessing and accepting whatever plays out. Most sbc combinations are plenty happy with 32-34 degrees max, all in by ???? rpm. What the initial timing is and when the advance is maxed out is what the timing curve is all about. Talk to GMC Bubba.

 

Here's a good article on Timing.

http://www.corvette-restoration.com/resources/technical_papers/Timing101.pdf

 

Set the total advance at about 32 with the vacuum UNHOOKED and plugged. Vacuum ads advance to the timing for economy and better idle quality and has no effect on wide open performance. Total advance should be set with no vacuum just as you would if you had a distributor with no vacuum advance to start with.

 

I always start about 12 and go from there. But 8-10 is as good a place to start as any.

 

Depends on your cam, Just go by this , The more radical the cam the more "Base"timing you will need.

Ditto on the 32 Total advise.

1. Stock cam (4-6 Degrees)
2. 327-350 style cam (8-12)
3. Soild lifter Bad *** cam (12-15)


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