Dual EMPI 44HPMX Tuning, What am I doing wrong? Options

[UkonCornelious]

I have recently gotten everything needed to get my car back on the road after 15 years of sitting. I have a newly rebuilt, street cam 2056 with dual 44HPMX EMPIs and I am trying to get it running better.

The engine sounds pretty solid when operating between 3-5k, but below that (and at idle) it doesn't sound great. There are lots of exhaust pops and the engine seems to sputter a little while cruising at constant speed.

I understand that you typically set the idle speed and then turn each idle screw in until the engine slows/ starts to die. Then you turn it out slowly until the engine runs smooth again. The problem is that the driver side carb doesn't seem to react at all when I screw either of the idle screws in all the way, and then backed out to 5 full rotations (which is the limit supposedly according to the video I watched).

Do I have the wrong size idle jets?

Are 44s just too big for this motor?

Do I have an intake leak?

Is the timing off somehow? (I originally set the timing with a light at break in)

What do you think I should check or measure to get my carbs tuned properly?

[rfinegan]

The Venturi size may be too big@ the stock size of 36mm for a 2056 unless your are spinning it real high
Most are better suited with 30 to 32 mm vents and can tune easier
Else get a jet pac kit from redline and keep tuning with a wide band o2

[UkonCornelious]

Thanks, rfinegan for the advice and information. I'll take a look at the jet pac kit when I get a chance.

Well, I went ahead and tried taking the idle jets out to clean them. There was actually a little debris in BOTH! After cleaning them out and reinstalling in the carb, the car seems to be much happier.

The low speed throttle response has greatly improved and there's much less exhaust pops while cruising.

I'm still a novice when it comes to tuning dual carbs so any help would be much appreciated.

[porschetub]

The Venturi size may be too big@ the stock size of 36mm for a 2056 unless your are spinning it real high
Most are better suited with 30 to 32 mm vents and can tune easier
Else get a jet pac kit from redline and keep tuning with a wide band o2

Yes to toning down the vents,not sure with these copies but think the smallest vents are 32mm but could be wrong thinking they are Weber based ?.
Always had thoughts about the effect of a small vent in a large bore carb ,could it be a bottleneck or increase the vacuum to a level that will help them work great ??.
Never been a concern for me cause I never over carb motors its not worth the hassle.
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[UkonCornelious]

I drove the car again today and it seems to be running very well. I can't really get on it but so hard since I'm still well under the 500 mile break in period, but she definitely wants to go!

[SirAndy]

On my 2056, i ran 40 webbers and i went all the way down to 32mm venturis which really helped with the off idle transition.

The 2056 just doesn't have enough displacement to generate enough air speed at lower rpms with large venturis.
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