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Discussion Starter · #1 ·
I know this has been delt with before and I've read most of the information available but I'm still at a loss :confused:
New looking 3310 idles rich, eye watering rich !
454, closed oval port heads, unkown hydroulic cam (about 540. lift) rhodes lifters, performer rpm, HEI, stock manifolds.
Initial timing between 16* & 18* BTDC, idle screws out 1 turn, butterflies fully closed, float levels right, idles @ 700 aprox. vacuum @ idle 16"
It was like this before I changed intakes.
Any help appreciated.
 

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Anychevy Dave

1. 16-18 degs initial timing....you are there already
2. set front float level so the gas only comes out if you bump the car
3. ensure the front of the primary blade is centered in the idle transfer slot....should look like a square grain of sand if you look down the primaries with the engine off. You may need to adv the timing a degree or two more....20 initial is fine if needed...just have to watch your total. (above this is old-school drilling the front throttle blades or opening the secondaries a tiny bit....
4. occasionally people blow a power valve but I do not think this is the issue.
5. get a vacuum gauge. Idle the car down, adjust one side for highest vacuum, then the other. Reset idle speed....set the idle screws again for highest vacuum.
edit: do this 3-4 times...keep resetting the idle speed lower each time....

Emissions can be greatly reduced by turning the screws in 1/8 turn from best vacuum.
 

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Discussion Starter · #7 ·
If every 2 increments of the timing tab is 2* then it's @ 18* initial and 36* total with vac unplugged
Rear float dribbled a little while idleing then stopped, so I'll back that down a little.
My vacuum gage is just a modified "in car" economy gage, so I'll need to get a real one.
One idle screw seems alot more sensitive than the other ?
Thanks George :thumbsup:
I'll check on the transfer slots tomorrow, my clothes stink of exhaust and I'm over it for one day.
But this problem aside, the car is alot more street friendly with the duel plane.
 

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Front jetting is typically 72 with a 6.5 PV
Typically the idle circuit is the boss till 2000+ rpm////jetting should not be a factor at idle.
Interesting the Alger guy's idle cleaned-up with a jet change....
 

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But this problem aside, the car is alot more street friendly with the duel plane.
Absolutly, the torque is down where You can use it now.:yes:. Don't get much chance to wind them up on the street anymore.
 

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Take the idle mixture screws out and blow through them with some compressed air to make sure they are not plugged. Make sure the little gaskets on them are good and screw them back in and then out about 1.5 turns. Also check the transfer slots to make sure they are clear and can get some air in past the throttle blade. At 16" of vacuum make sure your power valve is good and around 6.5 to 7.5. With idle at 700 the transfer slot should be exposed and you should not have to drill holes in the throttle blades. The jets do not affect the idle circuit.
 

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Discussion Starter · #14 · (Edited)
The secondary blades were open a little @ idle, so I reset them closed
I guess that's why there's rear a metering block available ?
Then cleaned out and readjusted the primary idle mixture, set idle @ 700 again and we seem to have a definate improvement (still a little rich) but acceptable for a holley :D
Thanks guys
 
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