Set & Tune Holley Carburetor Accelerator Pump Circuits
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- Опубликовано: 8 сен 2024
- How To Set & Tune Holley Carburetor Accelerator Pump Circuits. This video takes you through basic accelerator pump arm setup techniques and then looks at tuning shooters, accelerator pump cams, swapping in a 50CC "REO" kit and more. It's the third video in our Holley Tuning Series -- the first two videos deal with setting floats along with setting idle mixture and idle speed (Check Them Out!).
what a great video easily explained and he dose not carry on and on like others thanks this was very helpfull
Glad you enjoyed it!
I have a 5.3 LM7 V8 that has a large cam, edelbrock air gap intake, 1 3/4" long tube headers, and a Brawler 750cfm carb that was worked over extensively by a local carb shop. The carb now flows around 900cfm and the car was dyno tuned to make 385whp/320whtq. Car idles great and cruises very well, but off idle it hesitates. Took it to a local parking lot and tried to do some launches and the car would stumble before picking up and taking off like a rocket. The AFR gauge in the car went to 18:1 during the hesitation before going back to a healthy ready once the car took off. I began going up pump sizes to try and tune this out. At front nozzle size 42 and rear nozzle size 37, it was slightly better, but not enough to make much of a difference. The car would actually stall if I hit the gas full throttle in park. Today I jumped the front nozzle to 45 and the rear nozzle to 40 AND changed to the hollow screw type. Now It doesn't hesitate in the same way, but its not a crisp throttle. It also back fires out the carburetor with this size. DId I go to far? I was thinking about going back to the 42/37 combo but leaving the hollow screws, but at the time of this writing, I haven't done that yet.
I had a bad stumble. If you got on it real hard it would lean pop through the carb. I went from a 31 nozzle to a 35 nozzle and it went away. Now it runs a little rich. I'm going to play with pump cams next. Currently has a black one in it, on the #1 setting. Going to go to red on the number 2 setting, then go from there. Aluminum head BBC, big cam, big stall, single plane intake, 850 carb, nitrous.
4:11 gear, but its an ole heavy c10.
Excellent video.
Thank you! I try my best to make my videos informative.
This video is excellent thank you so much! For some reason the carb on my 454 had a 30 cc in front and 50 in back? What's your thoughts?
I love your channel. I bought a Quick Fuel Slayer 600 electric choke. It came with an .018 discharge nozzle??? Like you stated. Numbers 25-52….and unusual install/find?….
Excellent video. Well done sir!! Thank you for sharing your knowledge. Cheers from Motown!
Glad you dig it! Thanks for the comps!
Very well done!
That’s one the down sides to trying to run a 4500 style carb on the street as little as that might be but the accelerator pump cams are limited to 2 one that empties the entire reservoir an 1 that does not. Though I’ve gotten pretty good at having a few extra yellow ones around and file them to fit the speed and duration.
That's a really good tip for the folks running Dominators! I'm assuming you're using a two circuit carb?
@@lonewolfhotrods yes sir I am. I’m far from stupid but I’ve never been able to quiet get a 3-circuit to not run extremely fat especially on the street cruising around. It was always one extreme to the other never a happy medium. It was a constant feast or famine of fuel with a 3-circuit.
@@85gbody97 I certainly hear you...L-O-L.
Excellent video! I guess I will try the yellow pump cam. I already have a 63 squirter in there and she still stalls out when I punch it from a stop. I have a mild cam 264 .450 in a 318 poly head engine
Thank you for the compliment. I'm guessing the car doesn't have much rear gear, and if that's the case, it will need all the help it can get from the pump shot.
@@lonewolfhotrods yeah it's got 293s. It stalls even when in park and I punch the pedal
@@Minervagunsmithingllc If you still have the stall try going to the 50cc kit. I had a stall for years and tried every cam and squirter. This finally fixed my issue
very well done
Thank you! Cheers!
Great video sir, im stepping up to a 50cc pump. And the refresher was perfect, thank you 😉
Does the 50cc pump upgrade only work with the brown and yellow cam? Or can all cams be used?
50 cc kit works with the brown and yellow cams only. Hope that helps!
How do you know if a power valve works or is blown?
I was wondering when a foot brake racer has to come up on the converter to say 2000 rpm wouldn't it be better for the primary pump cam to be in the number 2 hole giving you more duration and shot than it would in number one since you've already come up on the cam 20% or so?
I have a question about the hole size in the shooter. You stated the hole size is the drill size. However, the larger the drill number means smaller the drill size. A 40 drill bit is smaller than a 28 drill bit. Can you please explain?
Thank you. I have a 4175. When I removed the squirter there wasn't a check valve needle. I did some research and I think there isn't a needle under the squirter on the 4175. Can you confirm this?
Holley shipped me a replacement 660 Truck Avenger and I lost my card for how I had carb tuned so starting from scratch. SBC 395 roller cam vortec, have off idle stumble was trying to tune out. They shipped the carb with a pump that would not squirt when cold, it was rock solid, so I pulled a spare from a Demon rebuild kit that would squirt. In my tuning, was getting nowhere going slightly larger on squirters, 28 to 31, and swapping cams and could not get the stumble out. So I look down carb at flow from squirter and looks like bubbles just off idle then a stream, is this the pump I used, maybe not moving and just flexing the contact point of diaphragm, I do have couple others to try. Or is there something else to look at, float levels are set to just trickle from sight plugs, had been running non-ethanol until price jump, so did not re-adjust to just below, but concerned over these bubbles and the stream just not giving me any fuel, no amount of adjusting will fix that... pump?? bad back so asking first...
While waiting for a carb I tossed a 650 BG Speed Demon on her so could drive it, that carb was tuned for a big block, ran a little rich, but did not have the stumble like this carb, so might just swap it back for winter. Not happy if I have to dig into this warranty carb Holley had to build for me, took 3 months to get it, already dealt with stuck pump when -15F last spring up here. They sent me a pump after I already put the spare from kit in it if thoughts are pump, or have pile of jets the BG would be near sure thing down a few sizes , lifted plow truck n bad back, snow coming, no joy... Wish pump was on front like those old Fords...
About bog when car is only in gear?
Not a lot of info but I'm guessing you need more pump shot.