what carb?

[billy]

ok fellas
you guys have never let me down so far so here goes.
i have a stock rebuilt 1981 ford 302 engine.
i got it with a holley 4412 carb.
it is my understanding that the carb is primarily used by circle track racers
and as such doesnt really belong on this engine.
my question will probably seem out of place on a hotrod forum but
what carb will give me the very best gas milage in a 2300lbs car with a 3.00 rear end and c6 tranny?
i rarely go over 65-70mph

 

[billy]

i havent opened it up yet.
but i did take some vacuum movies.
one is of the engine in drive

and the other is me punching the throttle


from what i have read i should put the automatic tranny in drive and the divide my vac reading by 1/2 and that would be the correct power valve to use.
so i guess that would be a 6.5 Hg

 

[billy]

i just don't want it to die at stoplights and bog way down when accelerating anymore

 

[eyesore]

That sounds like a jetting problem to me! I like Edelbrock 500's & 550's. Decent out of the box carbs that typically deliver good gas mileage.

Isore

 

[rainman]

I run a 4412 on my truck, runs great!! Its a mildly built 4.3 V6, 4 bbl. head and intake, marine cam 1.6 ratio roller rockers!!!
These are very simple easy to work on carbs, don't know why anyone wouldn't use it if you think it's enough cfm's??

BTW, these guy's running them on circle track cars are making some pretty big power with them!!

 

[sgtpontiac]

I will refrain from comment as I ..

dislike Holley Carbs on a street motor.....didn't even like the gm ones that had them from the factory.....temprimental and (sorry I said I wouldn't comment)

 

[donsrods]

I'm also not a fan of Holleys. They are admittedly a little better in the HP department but you can't beat an Edelbrock 500 or 600 on the street. Smooth, troublefree, and good gas milage.

Don

 

[billy]

it seems half and half
millions love em
and millions hate em.

personally i dont care either way
i just want it to stop dying at stoplights

 

[Old Iron]

I have been a Holley fan ever since I seen one and once I set them I don't have to fool with them. Not everyone has good luck with them on the other hand the same can be said for all the other types too
1. Most times if the engine dies at idle the number 1 cause is from a vacuum leak
2. If it boggs on hard acceleration the accelerator pump's bad or out of adjustment
3. If it coughs and dies on acceleration it's accelerator pump.
A stock 302 should have no bigger than a 600 to 625 cfm 4 bbl carb.
For fuel mileage the Carter's and Edelbrock's are the choice and I might say deliver very good performance too.
A simple rule of thumb is that for a super crisp throttle response smaller carbs are the answer.
Do not use a single 2 bbl, a 4 bbl will almost always get better fuel mileage.

 

[Tim...Ok]

I'd drop a brand new Edelbrock 500 on it and not give it a second thought for the next 5 or 6 years..Don't care for holleys on the street,especially not on a daily driver..

 

[Old Iron]

I went back and viewed the video and I agree with Tim and the others on the Edelbrock, that carb needs rebuilt anyway.

 

[motrhd]

A lot of good advise here, my rule of thumb has always been run a Holley(I prefer Demon)for all out performance or racing, and run an edelbrock on the street. I have even run a dominator on a big pro-streeter. An Edelbrock 600 would be great on that 302 and should provide good mileage. I just bought an Edelbrock 750 for my 351W build. And there's my $ .02 worth.

 

[Dr Crankenstein]

Uh, guys? A 4412 Holley is a 2bbl carb, not? How do you bolt a 4bbl Eddy on a 2bbl intake?

I happen to like Holleys, and don't find them difficult. (Mind you, I know one of the best Holley guys around. That helps!) I would find out what's ailing the carb you have. Old Iron gave you a good start. Too little timing, or a dead vacuum advance will make it cough and die, too.

 

[sgtpontiac]

Holley two barrel or 4.....don't like em..

Uh, guys? A 4412 Holley is a 2bbl carb, not? How do you bolt a 4bbl Eddy on a 2bbl intake?

I happen to like Holleys, and don't find them difficult. (Mind you, I know one of the best Holley guys around. That helps!) I would find out what's ailing the carb you have. Old Iron gave you a good start. Too little timing, or a dead vacuum advance will make it cough and die, too.

Not that they are difficult to work on....just they need way too much attention and you better have things set up properly or they just give you fits....some people swear by them....I swear at them....lol

 

[donsrods]

I'd put a Performer intake on it with a 500-600 Edelbrock and call it good.

Don

 

[rainman]

My old truck hasn't been started in two weeks and I'll bet it'll start within 10 turns sit and idle, and I don't use the choke!!! I don't know how much easier anyone would want it?? I do have electric fuel pump which helps the starting aspect a little!! I like the Edlbrock too, but you're comparring $400.00
to $25.00, I'll go the cheaper route, every time!!

 

[billy]

My old truck hasn't been started in two weeks and I'll bet it'll start within 10 turns sit and idle, and I don't use the choke!!! I don't know how much easier anyone would want it?? I do have electric fuel pump which helps the starting aspect a little!! I like the Edlbrock too, but you're comparring $400.00
to $25.00, I'll go the cheaper route, every time!!

me too.
heck i can barely make rent
i sure aint gonna go nuts and start buying intakes yadda yadda

 

[440Clark]

Okay then, we have to go back to Old Iron. Assuming your ignition timing is set correctly (10-15 degrees initial, 35-40 total), like he said, bog on take off is accelerator pump. Check for slop at the plastic cam, should get instant squirt coming out of discharge nozzle but a little slop at WOT so you don't rupture the diaphram. Change plastic cam, bend arm or adjust the length of the screw that strokes the pump. Stall at idle? bust out the squirt bottle & check for vacuum leaks. A rebuild kit for this carb is cheap. You can make it work, dig in!

 

[rainman]

Agree with the above!!

 

[Old Iron]

From the sounds of the video the carb is not delivering the gas it needs for the engine to accelerate.
With the engine not running take your fingers and see if the accelerator pump arm (the one with the bolt and spring has movement (slop) if it does take a pair of 3/8 or 7/16 wrenches and loosen the bolt until the arm does not have slop, then tighten the bolt until you have just barely enough slop to feel.
Start the engine see if the response is better.
If not, with the engine off look down into the venturi and see if you are getting a good squirt of gas when you move the throttle with your hand.
If not the accelerator pump is most likely bad (replace with new one)
The newer Holleys are really bad about the little red accelerator pump check valve in the float bowl breaking off or goin bad, we may have to check that.
Then re-post and I'll help you through the next step