Thread: '32 w/ Holley carb stumbles on acceleration....

Tweet

....Hello Everyone! I have a 413 small block Chev motor in my '32 with a Holley 750 Double Pumper {mechanical secondaries}. This carb was gone through by a professional carburator shop & was supposidly set up for my application {413, 10 to 1 comp, 230/236 @ .05 cam, RPM air gap manafold, 1 5/8" headers, 2800 stall converter. They asked & the place that built the motor gave them some spec's on timing, etc.} Anyway, when I punch it it just bogs & goes nowhere for 2 seconds or so. Then it takes off like a rocket .... But WHY the 'bog'??? This carb used to do this before it was re-done by the carb shop {years ago on this motor w/ a different cam}. I told the carb shop about this but now it does it worse! On dyno day when my engine was dyno'd the last thing we did was increase the jet size from 70/82 to 71/83. It put out like 1 more HP & I said just leave it like that. The guy running the dyno said these juts might be to big. Could this be causing my problem??? THANKS Everyone, Bill

.....Pump shot??? humm, I don't know exactly what that is but I'll go to the Holley web site & see if they show were/what it is.... Thanks Denny, Bill

....Whew, ok I'm confussed, I went to the Holley web site; is the 'shooter' or 'squirter' the same thing as a the 'pump shot'??? If so, I know WHERE it is .... & sort a WHAT it is .... Ok, then I went to Jegs Catalog; I see they have a Accelerator Pump Kit w/ squirters, gasgets, check valves, check weights, screws, pump cam selection & 50 & 30 cc diaphrams. Do I need this stuff??? And then I also see Pump Nozzles, do I also need these??? If so, what size pump nozzles??? What I got out of the Holley web site was that I need to change the pump discharge size & the pump cam profile.... THANKS, Bill

Its just that Nevada heat You know how the desert can be

Call the carburetor shop. If they set it up and it is not right, they should supply you with the appropriate parts to tune it. It sounds like you may need more pump shot, so I would change to a bigger pump cam before you change to larger squirters.

Have you checked the pump shot ?

Remove the air cleaner, look down the carb, twist the throttle, notice if there is a strong steady squirt of gas happening.

You may see no squirt, or a intermittant squirt, mist ,squirt.

Don't Forget The Safety Glasses.

I'd guess you have a 30cc Accelerator Pump, this can be changed to a 50cc Accelerator Pump with a holley kit, also holley has a Accelerator Pump Cam Assortment Kit that will help you fine tune your set up, good luck with it and keep us posted.

I think you should seriously consider buying this book or one like it. It has a ton of information on tuning Holley's

did you set the air rap or lack there of from the pump arm is the pump arm hitting the intake and stopping the travel of the pump shot .the tub squirters may help is to