Timing issues

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36 is an aweful lot for initial... you're gonna grind some starter teeth when you go to crank the motor fires at 36deg idle...
... Why do you want such high timing? You're sacrificing alot of top-end with that much advance.
... I'm still thinkin... set it to 36 when the motor stops advancing, (should be around 3500-3800rpm), and experiment with vac advance vs no vac advance...
I really don't think vac advance is needed here... but if that's why you want, then play with springs... I'm using medium stiffness springs in mine.
 
Wut should my timing be at idle with the vac. Adv. Hooked up. I have it connected to ported vac. I wanted to switch it to manifold vac. That's were I got the 33 degrees at idle.
 
to set the timing plug the vacuum advance and bring the car up to operating temp and at idle...adjust your initial timing and rev the engine till the advance stops and check the rpm, that's the rpm where your mechanical advance maxes out. If it got there too quick you need to change the springs and if it got there too slow you need lighter springs and different weights.

HEI distributors have 21* mechanical advance so whatever your initial timing is add 21* to it and that's your total advance. It should be in the 32* - 34* range. The vacuum advance is only there for light and moderate acceleration to give the engine the power it needs. As the rpm's increase the vacuum drops so the vacuum advance is gone when you have your foot into it. Don't bother checking your timing with the vacuum advance as it has nothing to do with the actual timing. It's the mechanical advance and the total timing that is important.

a ported vacuum shut off at idle
 
Ok well if hei distributors ad 21 degrees mechanical that would put me at about 12 degrees initial, then when I hook up the vacuum adv. It's brings the timing to above 30. And I hear a sputter I'n the exhaust while idling. Should I get an adjustable vac canister
 
that sputtering is the large lobe overlap on your big duration cam... The exhaust duration is larger, so you're getting larger overlap, and it's specially noticable at idle speeds.
... I wouldn't worry about a vacuum can, cuz your intake duration is still manageable for street use. I am running a 236 duration as well, and I use my car for daily in rush hour.
... if you plan to sit at red lights for 5mins or more, your brakes might get a little gooshy... but who sits at a light that long? And worst case, you can throw it into neutral to get off the convertor.

if you're worried about exhaust sputtering... turnup the idle a little bit... what is it idling at right now? Try 900rpm

vacuum is best on a manifold port... But most (if not all) carbs have a direct vacuum port on baseplate... which is equivalent to direct manifold port. Your brake booster should be plugged here. There should be a secondary direct port on the baseplate for vacuum advance... you can plug your vac advance here, rather than drilling into the manifold.

12deg initial sounds about right... then you have a 21deg curve between the vac advance... which will land you around 33 deg total.

... try bumping up the initial to 13 or 14 deg, so you land on 35 or 36 deg total.

for racing or spirited driving... disconnect vac advance and plug it, so you go from initial straight to total.
 
I built it my self, machined the motor .030 over, comp cam 282hr, aluminum chevy phase 6 heads 55cc combustion chambers, edelbrock rpm air gap intake, roller rockers, flat top pistons, 650 proform carb., with a Muncie 4 speed trans., and a 3.73 rear. I think Iv got the timing. I was running ported vacuum all this time because my father said that's were the vac. Adv. Went. I went to reading up on it and relized it should be on manifold vac. So I recently switched it over. So anyway I set the timing at 13 initial. 35 total. With vac hose connected at idle it's 34. I did a 3 gear launch and no detonation. Cranks over fine, starts right up. The car runs cooler, and 10x better. Just has a sputter at idle and when I go to shift, but I think that is the lobe overlap. Again Thanks for the info I appreciate it. Helped out alot.
 
you're welcome...
you have a very similar cam to mine... 282S here.
Now that you have that timing nailed down, you can experiment with how early you want full advance to come in...

... that's what I'm playing with right now.
 
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