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Discussion Starter #1
406, flat tops, bottom end stock otherwise, mild cam, 487x heads, performer intake holley 750 vac sec., 4 spd. msd hei stock config., what would you guys recommend my total timing to be set at? i was thinking somewhere in the 32 to 34? what rpm would i bring it in at 2500 to 3000? i dropped my dist in, fired right up ran smooth with a 600 holley, havnt pulled timing yet, just drove it to see how it did, had a popping in mid throttle, left as i reached redline, thought it was lack of fuel, swapped to 750 still pops a little, so im going to try to dial timing in and go from there. any other ideas?
 

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About 12 initial and 36 total should get you close.
 

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Start by setting the mechanical at 36 degrees at 3000 rpm and let everything else falls where it falls. After you set the mechanical, attach your vacuum advance to manifold vacuum.

Good luck!
 

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do you guys think the popping is a timing issue?
Certainly could be,the first thing you want to do is baseline the timing (as long as your valves etc. are adjusted correctly, otherwise that would be first).
What cc are those heads? If they are a smaller chamber, like 64cc, your compression could be up there in a touchy zone on pump gas with flat tops, watch out for detonation. But as was mentioned cam timing etc play a big role in the timing and tune, so knowing that would help.

I think 35-36 total is a good start.
 

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Discussion Starter #8
got timing set tonight. drove car, accel several times hard only popped once or twice, new carb, checkes set screws when i got back they were only out about 1 turn. turned them out to 1 1/4 to 1 1/2, will try again tommorrow. runs strong, think it needs a little more fuel.
 

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Try shooting some ether around the manifold when it's running - just stay away from the distributor with it - if you have a vac leak it will rev up when you spray it.
 

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checkes set screws when i got back they were only out about 1 turn. turned them out to 1 1/4 to 1 1/2, will try again tommorrow
Carbs are 2 separate carbs in 1
1/ the idle circuit that has no effect once off idle rpms
2/power circuit that is shut off at idle
Dont confuse the 2.
 

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My 406 runs 16* initial and a total of 36* and I use ported vacumm which is a whole other issue with many opinions. I've done both, I just prefer the ported over manifold for having a lopier idle with the cam I run. As was said earlier, you get a starting point and find what your motor likes, and yes it sounds like you are running lean, check your plugs to see.
 

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got timing set tonight. drove car, accel several times hard only popped once or twice, new carb, checkes set screws when i got back they were only out about 1 turn. turned them out to 1 1/4 to 1 1/2, will try again tommorrow. runs strong, think it needs a little more fuel.
You should use a vacuum gauge to adjust the idle mixture screws (warmed-up, normal idle rpm, adjust for highest steady vacuum).

:beers:
 
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