z ya Posted March 31, 2002 Share Posted March 31, 2002 I have the 3310 holly vac sec and am having some issues with it idling the way it should in gear. The car idles great in park but when I put it in gear it idles down to 600 rpm. The cam is a 286/ 490 comp cam. Well, nedless to say this cam is not happy at this rpm. Even if I raise the idle in park to 1000 rpm as soon as i put it in gear it drops to 600 rpm again. I talked to a carb guy and he suggestedthat I drill a 1/16 hole in each butt- fly on the primarys. he said this with give the motor more vaccum and more air at idle so that I can turn my curb idle down. Has anyone tried this trick? Quote Link to comment Share on other sites More sharing options...
blueovalz Posted March 31, 2002 Share Posted March 31, 2002 I'll bet when Grumpy wakes up, this can be his coffee and toast editorial. In the mean time I'll take a stab at it. drilling a small hole in the throttle plates is an old trick (to avoid the use of the transistion from idle to open throttle circuits??, it's been a long time on that old trick, and too many cobwebs this time of the morning up there). My first question is what is the stall speed on your torque converter. Have you installed a smaller converter to allow the engine to idle in gear at a higher rpm? Quote Link to comment Share on other sites More sharing options...
z ya Posted March 31, 2002 Author Share Posted March 31, 2002 I AM RUNNING A 2000 STALL. Quote Link to comment Share on other sites More sharing options...
v8260z Posted April 1, 2002 Share Posted April 1, 2002 Your problem is in the covertor stall speed.With my experiences , until you buy a 10" convertor your going to have this problem.My 9" Continental drops from 1050rpm idle to 850rpm in drive. I suggest not drilling the holes in the carb to solve this problems. The holes are drilled for air/ fuel tuneing at idle. Quote Link to comment Share on other sites More sharing options...
Mike C Posted April 2, 2002 Share Posted April 2, 2002 I also would guess converter. The holes are to increase airflow without increasing fuel flow. It is designed as a crutch for engines with a very large cam. If you need more air, you can adjust the rear throttle blades with a screw that is only accessible with the carb upside down and off the car, but I doubt this is your problem. You can only go so far with the rear throttle blades before they uncover the transition slot and fuel starts to flow through the secondary system. That's when holes are drilled in the throttle blades so they can be closed but still have increased air flow. Quote Link to comment Share on other sites More sharing options...
z ya Posted April 2, 2002 Author Share Posted April 2, 2002 Thanks guys, I guess I will have to live with it until I want to pony up for the 500 dollar converter! Quote Link to comment Share on other sites More sharing options...
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