Carb issue?

mr. fix it

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Thanks for the info! I was planning on upgrading the carb to a 500 cfm next year sometime but wanted to see if I could get the stromberg there. The "sags" or stumble happen at cruising speed all the way through which was down my road at 40 mph at about 1600 rpm. Idle in N is about 700 and when brakes are applied and in D I think its about 550-600 but will confirm later today.
I remember in my younger days doing a similar thing leaving the stock 2bbl on a mildly upgraded 351w Ford engine
What you are describing brings back memories of drivability issues with that engine.
Definitely sounds like fuel starvation

be careful with running lean if you’re pushing the engine trying to have some fun with it until you can update to a 4bbl setup

The 2bbl isn’t up to the task
 

Rooster34

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I remember in my younger days doing a similar thing leaving the stock 2bbl on a mildly upgraded 351w Ford engine
What you are describing brings back memories of drivability issues with that engine.
Definitely sounds like fuel starvation

be careful with running lean if you’re pushing the engine trying to have some fun with it until you can update to a 4bbl setup

The 2bbl isn’t up to the task
You must have posted before I updated this post the other day. I ended up get a holley 500 2 bbl but I'm having issues with that. If you got back to the first page and go to the bottom I explain what's going on. I just replaced the squirter and the jets, jets are now at a 76 and the squirt is a 31. If I'm at a stop and punch the gas she stalls
 

mr. fix it

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You must have posted before I updated this post the other day. I ended up get a holley 500 2 bbl but I'm having issues with that. If you got back to the first page and go to the bottom I explain what's going on. I just replaced the squirter and the jets, jets are now at a 76 and the squirt is a 31. If I'm at a stop and punch the gas she stalls
Ok
I confess that I didn’t read every response
Will think on it and see if I can suggest something else
 

Rooster34

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---UPDATE---

So I started to play around with the Holley 500 over the past few days, as mentioned above I put 76 jets in and I upped the squirter to a 32 from a 31. She still needs more fuel so I'm going to up it to a 37 get the 50cc accelerator pump kit and she how she likes that and draw down if needed or draw up if needed. I also upped the timing to 38 deg. At 3000 rpm no ping or detonation and drive ability seems to be getting better. I'll keep you guys updated
 

Rooster34

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---UPDATE---
Alright guys and gals, so after doing a little but of research the holley 4412 comes standard with a 50cc accelerator pump, so I am going to up the squirter to a 37. I'm not sure on upping the 76 jets yet, and here's why, at a stop light idling it idle pretty smooth but there is a very subtle "blip/skip/stumble" nothing that would make it stall and when cruise with light pressure on the pedal she is as smooth as goose poop. Should I up the jets? Is that the "skip" I feel when in drive at idle being too lean or too rich? All your help is appreciated!
 

Davea Lux

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---UPDATE---
Alright guys and gals, so after doing a little but of research the holley 4412 comes standard with a 50cc accelerator pump, so I am going to up the squirter to a 37. I'm not sure on upping the 76 jets yet, and here's why, at a stop light idling it idle pretty smooth but there is a very subtle "blip/skip/stumble" nothing that would make it stall and when cruise with light pressure on the pedal she is as smooth as goose poop. Should I up the jets? Is that the "skip" I feel when in drive at idle being too lean or too rich? All your help is appreciated!

Skip at idle is not controlled by the main jets. Try opening up the idle jets about 1/4 turn and see of the idle smooths out.

Dave
 

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Another update for ya guy, so as she sits right now I have a 45 squirter in the holley 4412 I still get that lean stall if I punch it from a stop. The carb has the red accelerator pump cam on it and it's in position 1. I just ordered some bigger squirters so hopefully that fixes it. I have a 47, 50, 55, and a 63 coming. I guess my question is if those don't fix the issue what the hell would be next to fix the issue? I have been reading on the holley website about tuning these and they say that sometimes a bigger squirter isn't always the answer. I do have a 10.5 power valve in there but I can't imagine that would have an affect but maybe it does, hopefully there is a holley tuner guy or girl here that can help!
 
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