What size carb do you have on your 440 ?

[rog_allen]

What size carb do you have on your 440 ? I have a 440 nothing fancey
mild cam headers just ordered a Edelbrock 7193 dual plane performer intake, 4 speed trany
I want a holley you recomend a 750 or 850 ?

 

[WileERobby]

IF you have to have a Holley, a 750 vac secondary is plenty. Forget the 850 for your application. BUT... I'd recommend the Edelbrock Performer 750 electric choke.

 

[brandon64]

I would not run a vacuum secondary on a 4 speed car. I'd go with a 750 mechanical secondary if its going to spend most of it's time on the street. Start out with #73 jets up front and #68 in the back and fine tune it from there.

 

[WileERobby]

Even though it's a manual trans, a mech secondary carb would be a mistake. On a heavy b-body, with only a mild cam & dual-plane used on the street (& probably not stiff gearing), vac secondary is better.

 

[brandon64]

Even though it's a manual trans, a mech secondary carb would be a mistake. On a heavy b-body, with only a mild cam & dual-plane used on the street (& probably not stiff gearing), vac secondary is better.

well I am just recently a b body owner. I've fooled with a bodies alot and that set up worked the best for me (with aggressive gearing) I'd like to better understand how weight and gearing add into the factor? And dual plane intake is the only way I would go for a street car, single plane intake is not for the street. I could see if you were putting around like grandma maybe trying to get the best fuel economy out of a 440 I would run a vac secondary carb. But I believe the mech secondaries would out perform. Please correct me if I'm wrong. I'm just saying what my experience has been.

 

[WileERobby]

Definitely, with a light a-body, good cam, and stiff gears, a mech sec is the way to go.

 

[WileERobby]

Weight & gears are very important = engine load. Think of extremes: heavy 3800 lb. car with 3.23 gears vs. light 3200 lb. car with 4.10 gears... both cars going 10 mph in second gear, and you floor the pedal. I think you know what the results will be.

 

[brandon64]

Definitely, with a light a-body, good cam, and stiff gears, a mech sec is the way to go.

How does weight and gearing make a mech sec a no go? not doubting you just curios.

 

[brandon64]

Weight & gears are very important = engine load. Think of extremes: heavy 3800 lb. car with 3.23 gears vs. light 3200 lb. car with 4.10 gears... both cars going 10 mph in second gear, and you floor the pedal. I think you know what the results will be.

3200 pound car with 3.55. and if i'm going 10 mph in second and want to go fast I hit first gear then floor it.

 

[WileERobby]

You're missing the point. I'm trying to explain how weight & gears correlate to engine load.

 

[brandon64]

You're missing the point. I'm trying to explain how weight & gears correlate to engine load.

thats what I want to understand. I don't see why more air and fuel during a wide open condition regardless of weight or gearing would result in less power with enough RPM?

 

[Revhendo]

And not every rule is set in stone. I run a Holley Strip Dominator intake on the street. It's on my stroked 340 and am running a Thermoquad. Installed in my none too svelte 73 Roadrunner, it was a beast. (It's going in the Valiant).

 

[Revhendo]

thats what I want to understand. I don't see why more air and fuel during a wide open condition regardless of weight or gearing would result in less power with enough RPM?

The vacuum secondaries work as an on demand system and will open when the engine is ready for it. Mechanicals are more of a take it bitch deal. A heavier car with taller gears needs to work up the engine speed. If you feed it all at once, it will bog. Or at the very least be real tweaky.

 

[brandon64]

The vacuum secondaries work as an on demand system and will open when the engine is ready for it. Mechanicals are more of a take it bitch deal. A heavier car with taller gears needs to work up the engine speed. If you feed it all at once, it will bog. Or at the very least be real tweaky.

but he's got a 4 speed if it bogs then down shift. I'ts not gunna bog at higher RPM's

 

[1badgtx]

I,m runnin a edelbrock 800 on my 440..It,s bored .30 over..I also have edlebrock heads and hooker super comp headers...I feel it,ll take a 850 double pumper..Gonna try that his summer..I agree with most of the previous posts..Vacum secoundaries with manuel and mechanical with 4 speed..
Petty Blue 67 GTX

 

[rog_allen]

WOW THERE IS ALOT TO CONSIDER ,iI CAN SEE CLEARLY WHAT EACH OF YOU ARE SAYING,
ISNT A EDELBROCK GOT MANUAL SECONDARYS ALSO? I WAS LOOKING AT THEM THEY ARE SOMEWHAT CHEEPER, I SEE THE 750 PEFORMERS ARE A 1407 , 1410 , AND A 1411 SO THATS CONFUSEING TOO,
I USED TO HAVE A 69 RUNNER 383 AUTO 750 DOUBLE PUMPER AND HAD A BIG DEAD SPOT WHEN YOU HAMER ON IT TILL RPM'S WERE THERE,I THOUGHT THIS WAS BECAUSE OF THE BIGGER CAM , MAY HAVE BEEN BECAUSE IT NEED WACUME SECONDARIES SO IT DIDNT TAKE ALL THAT FUEL BEFORE IT WAS READY FOR IT,, WELL THEN I CONVERTED IT TO A 4 SPEED AND WAS AWSOME CUZ I COULD KEEP THE RPMS WERE THEY NEEDED TO BE,
I WAS THINKIN THAT BECAUSE OF THE CUBIC INCH FROM 383 TO THIS 440 THAT I MAY NEED A 850 , BUT GUESS THATS NOT TRUE,,
VERY THANKFUL FOR ALL THE ADVICE , I LOVE THIS SITE!!, SEE I'M DISABLE AND CANT HARDLY EVEN STAND OR WALK ANYMORE, MY DREAM CAR IS A 71 ROADRUNNER 440 FOUR SPEED SO IM COLECTING EVERYTHING I NEED FOR MY SON TO PUT IT TOGETHER FOR ME

 

[Revhendo]

but he's got a 4 speed if it bogs then down shift. I'ts not gunna bog at higher RPM's

Not very efficient on a street car, wouldn't you say? A stick car is more tolerant of a mechanical secondary. I just don't consider it an option on a street car where driving conditions are constantly changing. It's about drivabillty. On a track car, with the right motor, bring on the double pumper.

WOW THERE IS ALOT TO CONSIDER ,iI CAN SEE CLEARLY WHAT EACH OF YOU ARE SAYING,
ISNT A EDELBROCK GOT MANUAL SECONDARYS ALSO? I WAS LOOKING AT THEM THEY ARE SOMEWHAT CHEEPER, I SEE THE 750 PEFORMERS ARE A 1407 , 1410 , AND A 1411 SO THATS CONFUSEING TOO,
I USED TO HAVE A 69 RUNNER 383 AUTO 750 DOUBLE PUMPER AND HAD A BIG DEAD SPOT WHEN YOU HAMER ON IT TILL RPM'S WERE THERE,I THOUGHT THIS WAS BECAUSE OF THE BIGGER CAM , MAY HAVE BEEN BECAUSE IT NEED WACUME SECONDARIES SO IT DIDNT TAKE ALL THAT FUEL BEFORE IT WAS READY FOR IT,, WELL THEN I CONVERTED IT TO A 4 SPEED AND WAS AWSOME CUZ I COULD KEEP THE RPMS WERE THEY NEEDED TO BE,
I WAS THINKIN THAT BECAUSE OF THE CUBIC INCH FROM 383 TO THIS 440 THAT I MAY NEED A 850 , BUT GUESS THATS NOT TRUE,,
VERY THANKFUL FOR ALL THE ADVICE , I LOVE THIS SITE!!, SEE I'M DISABLE AND CANT HARDLY EVEN STAND OR WALK ANYMORE, MY DREAM CAR IS A 71 ROADRUNNER 440 FOUR SPEED SO IM COLECTING EVERYTHING I NEED FOR MY SON TO PUT IT TOGETHER FOR ME

1407 - manual choke
1410 - marine (got a boat?)
1411 - electric choke

 

[Cranky]

I guess I'm one that breaks all the rules by running single plenum intakes and DP carbs on street cars. Most of my streeters were stock block engines with headers, very small cams, around 3.55 gears and most of them were heavy with automatics with slightly better than stock stall converters. A few of them were pickups too. If you can borrow a buddies carb, you can do some testing but I would say the 850 is a bit big for a mild engine. Keep in mind that DP's get pretty lousy mpg numbers in town....

 

[rog_allen]

Looks like im going with a double pumper,, thaks everyone for helping decide on the size 750,,new here but i'll try and add a quick pic of my car
thanks everyone !!!!!

 

[rog_allen]

1971 Sebring Plus , origunal faded paint no rust or bondo ever, nice start for our project, actualy i kinda hate to paint it ,such nice patina