mechanical or vac secondaries ??

[Rolling_Thunder]

Alright carb gurus...      I know HOW these both work -  but I'm not exactly sure why one is better than the other for specific applications...     explain this to me....        I am planning the build for a nice 440 for my road runner...     need some advice on a carb -  on a pretty tight budget at the moment...      Build is pretty basic...    iron heads, .030, hydraulic cam, duel plane intake, and some hooker headers I have kicking around....     

I was thinking just a 750 or 800cfm Edelbrock...     I know a lot of guys swear by holleys but i have never had a problem with the edelbrock carbs I have used....      point me in the right direction.

[charger_fan_4ever]

Alright carb gurus...      I know HOW these both work -  but I'm not exactly sure why one is better than the other for specific applications...     explain this to me....        I am planning the build for a nice 440 for my road runner...     need some advice on a carb -  on a pretty tight budget at the moment...      Build is pretty basic...    iron heads, .030, hydraulic cam, duel plane intake, and some hooker headers I have kicking around....     

I was thinking just a 750 or 800cfm Edelbrock...     I know a lot of guys swear by holleys but i have never had a problem with the edelbrock carbs I have used....      point me in the right direction.

If your looking for performance go with a holley style mechanical 4150 carb. IMO edelbrock carbs are for trucks or a show car. Nothing special about them they are pretty much a factory replacement. A good mix of performance,mileage,driveability on a heavier auto big block car car is a holley street avenger 770.

[71bee]

I restore/rebuild Carters & Holley's all the time. the Holley 4160's (vacuum secondaries) have always been problematic for me. personally, I prefer the older Carter AFB/AVS for street use & a good ol' modified Thermo-quad for racing.   

[terrible one]

From the Holley website:

For street cars the vacuum secondary carburetor works best on midweight or heavyweight cars with an automatic transmission. They are more forgiving than a Double Pumper is because they work by sensing engine load. The mechanical secondary carburetor is best on a lighter car with radical camshaft and a lower gear and manual transmission or on a car that is going to be used for racing purposes.

[firefighter3931]

Double pumper is alli willever use. 

Ron

[Rolling_Thunder]

Double pumper is alli willever use. 

Ron

God has spoken...      carry on all...            Looks like I'll go with a holley style carb with mechanical secondaries...     

[TUFCAT]

I agree that Ron is a performance God and I rarely waiver on his recomendations......but Holley's don't look correct on some Mopar applications.

When I say this of course, I know (based on memory) a good number of Mopars were equipped with Holley 4bbls from the factory  - such as some 1968 440's, and nearly all 1970-1971 383's, and 1972 440 Magnums.

[71bee]

I agree that Ron is a performance God and I rarely waiver on his recomendations......but Holley's don't look correct on some Mopar applications.

When I say this of course, I know (based on memory) a good number of Mopars were equipped with Holley 4bbls from the factory  - such as some 1968 440's, and nearly all 1970-1971 383's, and 1972 440 Magnums.

And the only 4 barrel Holley offered for MoPar engines was the 4160 (vacuum secondaries). the 4150's (double pumpers) were placed on GM & Ford applications. I will agree that the 4150 is the best Holley 4 barrel ever made, but the good ol' Carter AVS carburetors that were used on most HP MoPar engines back in the day are easier to tune & modify, plus they will hold up much better on the street.

[firefighter3931]

Double pumper is alli willever use. 

Ron

God has spoken...      carry on all...            Looks like I'll go with a holley style carb with mechanical secondaries...     

Lol ! No God here....just a Hot Rodder who's made many mistakes and learned from them !   

I agree that Ron is a performance God and I rarely waiver on his recomendations......but Holley's don't look correct on some Mopar applications.

When I say this of course, I know (based on memory) a good number of Mopars were equipped with Holley 4bbls from the factory  - such as some 1968 440's, and nearly all 1970-1971 383's, and 1972 440 Magnums.

And the only 4 barrel Holley offered for MoPar engines was the 4160 (vacuum secondaries). the 4150's (double pumpers) were placed on GM & Ford applications. I will agree that the 4150 is the best Holley 4 barrel ever made, but the good ol' Carter AVS carburetors that were used on most HP MoPar engines back in the day are easier to tune & modify, plus they will hold up much better on the street.

Just because it came stock on a factory engine doesn't mean it's the best option   

Nothing compares to a properly tuned double pumper, period ! 

Just ask Brian

http://www.dodgecharger.com/forum/index.php/topic,35989.0.html



Ron

[Cooter]

Double pumper is alli willever use. 

Ron

God has spoken...      carry on all...            Looks like I'll go with a holley style carb with mechanical secondaries...     

Why post the question to all here, if you coulda simply PM'd "The God"??

[71bee]

Just because it came stock on a factory engine doesn't mean it's the best option   

Nothing compares to a properly tuned double pumper, period ! 

Just ask Brian

http://www.dodgecharger.com/forum/index.php/topic,35989.0.html

I agree with your take on a stock carb not being the best option. that was my point. the only 4 barrel Holleys offered on MoPars were the 4160 -not the better choice by most. I'll still stick with a good ol' Carter or Edelbrock AVS. but as they say, to each his own. 



Ron
[/quote]

[mikesbbody]

"Just because it came stock on a factory engine doesn't mean it's the best option"
Thanks for bringing that up Ron So True IMO this one is kinda hard for me because 2 Guy's I really respect (Ron and E- Booger) both have different opinions when it comes to Carb choice.
Ron say's all he will ever use is a D.P  E.B tends to think a D.P is not necessary on a street car.
I want a crisp Throttle response so which should I go for? I have a 750 V.S Holley on a Single plane
Weiand Manifold on a warmed over 440 is it true D.Per's are better suited for single Plane Manifolds?
I recall reading that somewhere is that true?     

[Rolling_Thunder]

Double pumper is alli willever use. 

Ron

God has spoken...      carry on all...            Looks like I'll go with a holley style carb with mechanical secondaries...     

Why post the question to all here, if you coulda simply PM'd "The God"??

I guess it was a poor attempt at humor...     If i ask something publicly - generally I want more than one opinion.          Just seems like Ron is always around when we all need something answered

[71ChallengeHer]

I changed this year from a Edelbrock with vacuum secondaries. I switched to a Holley dump pumper with mechaniclal secondaries. My Chally is way more responsive now. I very happy with the change. I wish I would have done it sooner.

[mikesbbody]

Thanks Jackie  the way I see it is I have nothing to lose by trying a D.P the better response you get from your D.P is just what I'm looking for 

[RECHRGD]

I have a "heavy car with an automatic".  I changed from a Holley 750 vacume secondary to a D.P. years ago and never looked back.  It was a night and day difference.  Bob

[TUFCAT]

hmmmmm...now I'm starting to realize why Ron likes them, and why he recommends one for my build.

[terrible one]

Well damn . . . here I am with a 750 VS sitting on the shelf 

[mikesbbody]

I have a "heavy car with an automatic".  I changed from a Holley 750 vacume secondary to a D.P. years ago and never looked back.  It was a night and day difference.  Bob

Another success story great to hear that Bob  I too have a "Heavy car with an automatic" warmed over 440 Ron, if you read this do you think a 780 D.P would be too big? dont mind changing
Jet sizes etc.

[71ChallengeHer]

Thanks Jackie  the way I see it is I have nothing to lose by trying a D.P the better response you get from your D.P is just what I'm looking for 

Anytime, Mike.    I have my D.P. sitting on a dual plane. Works great. But I have a small block 

[mikesbbody]

Thanks again Jackie  I dont think the small block thing would change anything in fact, I often hear of S.Blks running them (only not as big as the Carbs on B.Blks) mine will be going on a Dual plane
The single plane will come off so it will be a carb and manifold change (possibly a gear change too)

[71bee]

I changed this year from a Edelbrock with vacuum secondaries. I switched to a Holley dump pumper with mechaniclal secondaries. My Chally is way more responsive now. I very happy with the change. I wish I would have done it sooner.

Not tryin' to stir the pot guys, but neither Carter nor Edelbrock ever made a carb with vacuum operated secondaries. they did, & still do make the AVS (Thunder Series) which has a vacuum operated secondary "air valve," just like the ol' Thermo-quads & Rottenchester quadraflushers. their designed to eliminate "bog" @ WIT. it's a fully adjustable air regulator that allows little to massive amounts of vaccum being pulled thru the intake, thus mixing with the fuel. it's not designed like Holleys 4160, which requires a good amount of vacuum to open up your secondary butterflies, thus drawing in your complete fuel/air flow.

Said it before, I'll say it again: the Holley 4150 D.P. is a good racing carb, but prepare to tinker with it at random for street use.

[mikesbbody]

No Pot stiring at all  71Bee  I am happy and interested to hear both sides