The Dart runs better than ever

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skep419

skep419

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Last summer I brought my car to a respected old school race tuner. The Dart wouldn't idle for nothing. He drilled holes in the primaries and it idle perfect. Since then there was a popping from the exhaust at cruise speeds. After reading a bunch on tuning I ordered new primary throttle blades and a accel 59301 distributor with the curve kit. Ditched the MSD pro billet with no vacuum advance.

I put the new dist in and set the initial at 17-35 total. Took it for a test drive idled way better. Still popped from exhaust. (figured it was the drilled throttle blades anyway but one thing at a time is what I've been reading)

Pulled the carb and swapped the blades. Fired it up and it was dead nutz idling at 1000 rpm. Took it for a cruise no more popping.

woohooooo:cheers:
 
I always think people are too quick to start drilling throttle plates. To me that's a last resort type of solution when most everything else is exhausted.

I bet you could have got the pro billet to work out with a bit of work.

Nice to read that you got it sorted out.
 
crackedback said:
I always think people are too quick to start drilling throttle plates. To me that's a last resort type of solution when most everything else is exhausted.

I bet you could have got the pro billet to work out with a bit of work.

Nice to read that you got it sorted out.
Click to expand...

Totally agree.It's a bandaid solution.

Congrats on fixing the problem! Most times when people have idle issues they look at the carb first. Im weird and look at electrical.
 
+ me........... adjust/rebuild/tune....then....maybe.....drill the throttle blades...I have never had to go beyond the first 3!
 
Part throttle the holes would cause a lean condition which would put unburned fuel into the exhaust (lean mixture takes longer to burn). The unburned fuel then blew up in the exhaust?

Talking from my:bootysha: no idea its the only thing I changed and problem went away.
 
Most holleys and carter carbs have vacum port tubes on the base of the carb,if they are not in use,unplug the port and see how it runs.The vacumn tube on the base is normally exitited in between the two primary blades and will act as if you drill the baldes.What you do then is put a small piece of rubber hose with a plug in it so you can drill the plug to the size you want,being able to adjust the amount of ait needed by pulling of the fitting and drilling and replacing it,mrmopartech
 
Drilling the throttle plates is to get more air in the engine at idle whithout opening the throttle blades too far and uncovering the idle slots when very large camshafts are used. Once you open the blades so far and uncover the transfer slots you aren't running on the idle circuit anymore, you are running on the main circuit.

It's a valid technique when used properly. If you have less than approx. 265* of duration @ .050 lift though then it's usually not necessary. You can crack the secondary side open to gain the air flow. Ideally you want no more than .040 of throttle blade opening measured with a wire gauge. If your engine won't idle on that and everything else is right, then drilling the blades is valid. But it should be a last resort.
 
Guitar Jones said:
Drilling the throttle plates is to get more air in the engine at idle whithout opening the throttle blades too far and uncovering the idle slots when very large camshafts are used. Once you open the blades so far and uncover the transfer slots you aren't running on the idle circuit anymore, you are running on the main circuit.

It's a valid technique when used properly. If you have less than approx. 265* of duration @ .050 lift though then it's usually not necessary. You can crack the secondary side open to gain the air flow. Ideally you want no more than .040 of throttle blade opening measured with a wire gauge. If your engine won't idle on that and everything else is right, then drilling the blades is valid. But it should be a last resort.
Click to expand...

I had a 18 foot jet boat with a 454 with a pretty radical cam and a 750 Holley. The thing wouldn't idle and the plugs were always wet. Drilled the throttle blades and it cleand it up and the idle was crisp.
 
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