Best carb for 440 engine

[Dominique Williams]

What would be some good recommendations on a carb I could get the most power from. I currently have a summit 750 carb on right now modified engine (aluminum heads, mild comp cam, forged aluminum pistons, forged steel crank, stock exhaust manifolds)

 

[Plybeep68]

Is the motor bone stock or modified?

 

[Dominique Williams]

Is the motor bone stock or modified?

Modified

 

[cbarge]

You can get more power by uncorking the restrictive factory logs from the aluminum heads and run headers
But that is off the topic.
The engine will tell you what it needs through fine tuning.
Every engine is different and being modified factory tuning specs are null and void.
That Summit carb is a good working carb especially on a mild 440.
I would see if you can get a tuning kit (jets/metering rods) and work your existing carb.
Runs lean at top end? Fatten up the jets lighten the metering rods, reset ignition timing, etc.
Test and tune, trial and error.
Use a vacuum guage and a good timing light and use your good ear to pay attention to the motor---she will tell you what she wants! Lol!
Good luck.

 

[Dominique Williams]

You can get more power by uncorking the restrictive factory logs from the aluminum heads and run headers
But that is off the topic.
The engine will tell you what it needs through fine tuning.
Every engine is different and being modified factory tuning specs are null and void.
That Summit carb is a good working carb especially on a mild 440.
I would see if you can get a tuning kit (jets/metering rods) and work your existing carb.
Runs lean at top end? Fatten up the jets lighten the metering rods, reset ignition timing, etc.
Test and tune, trial and error.
Use a vacuum guage and a good timing light and use your good ear to pay attention to the motor---she will tell you what she wants! Lol!
Good luck.

Appreciate it. Was looking at a edlebrock 800cfm avs2

 

[Xenon]

I love this type of question...
Let me be the first to tell you...
NO ONE can answer that question for you..
Because ---
Actual compression,, actual cam specs,, head volume ,, bearing clearances..
All required to provide you the most accurate starting point...
That being said, as noted above by cbarge, a vacuum gauge will get you pretty close...

If you want the best answer,, head over to DeLeon Dyno Performance at 1439 Laurelwood Rd, Santa Clara,
408-816-7779.

.

 

[mrfury68]

As stated above, a vacuum gauge & timing light are essential tools for dialing in and hearing what your motor is telling you. Patience is a must. Good luck & keep us posted.

 

[CBODY67]

In one respect, it will not matter much how much "more" carb you put on the intake manifold as long as the factory log exhaust manifolds are in place. Either get some Chrysler HP cast iron manifolds or quality headers, with a 2.5" pipe diameter exhaust system and mufflers. Let it BREATHE, which is the other part of the "engine as an air pump" equation.

"More" carb does not always result in better performance. Especially in the rpm ranges which comprise "daily/normal" driving. Aim for sharp throttle response off-idle and in mid-range rpm cruise situations, rather than worrying about that last 5 horserpower at 5000rpm. Unless you're always racing "head's up" rather than bracket racing.

A larger carb might end up in a better "top end rush", but if it takes longer to get to that point, you've usually lost the race as too much time was used by the lesser lower-rpm power to get "there". BTAIM

But until you open up the exhaust system more than it is now, it can all be inefficiently-spent funds to seek a bigger carb.

What are the cam specs? That way we know what you've got, rather than a "generic term" for lots of different cams. Which intake manifold?

Respectfully,
CBODY67

 

[Dominique Williams]

In one respect, it will not matter much how much "more" carb you put on the intake manifold as long as the factory log exhaust manifolds are in place. Either get some Chrysler HP cast iron manifolds or quality headers, with a 2.5" pipe diameter exhaust system and mufflers. Let it BREATHE, which is the other part of the "engine as an air pump" equation.

"More" carb does not always result in better performance. Especially in the rpm ranges which comprise "daily/normal" driving. Aim for sharp throttle response off-idle and in mid-range rpm cruise situations, rather than worrying about that last 5 horserpower at 5000rpm. Unless you're always racing "head's up" rather than bracket racing.

A larger carb might end up in a better "top end rush", but if it takes longer to get to that point, you've usually lost the race as too much time was used by the lesser lower-rpm power to get "there". BTAIM

But until you open up the exhaust system more than it is now, it can all be inefficiently-spent funds to seek a bigger carb.

What are the cam specs? That way we know what you've got, rather than a "generic term" for lots of different cams. Which intake manifold?

Respectfully,
CBODY67

I have a pair of these at the moment

 

[CBODY67]

I suspect those were pretty decent in 1959, when the 4bbl carbs were about 500 cfrm and most B/RB engines had the 252 degree/.390" lift cams, but I also suspect they were more restrictive than the normal '72 400-2bbl exhaust manifolds were. BIG bottleneck.

Thanks,
CBODY67

 

[live4theking]

Those manifolds will not accomplish the better braking that the guys ate making above. The HP manifold arc up towards the valve covers when installed.

 

[1970FuryConv]

I used Edelbrock AVS2800cfm on 440 with 9.2 compression, iron heads, .5" lift cam, HP manifolds with good results across the spectrum of engine performance. used TTI 2.5" dual exhaust kit.

 

[LocuMob]

Question, why are the love manifolds so crappy in your minds vs the HP manifolds? They are only rated 5-10hp over log manifolds, and didn't they change the cam when they went to HP manifolds on the 4bbl 383's? Been curious why HP manifolds are so sought after if there's only a minimal performance gain.

 

[carrman]

I used Edelbrock AVS2800cfm on 440 with 9.2 compression, iron heads, .5" lift cam, HP manifolds with good results across the spectrum of engine performance. used TTI 2.5" dual exhaust kit.

Using an AVS2 800 on my 440 with 8.6:1 compression, Stealth heads, .48"lift cam, HP manifolds and a 2.5" TTI dual exhaust. Works awesome.

 

[CBODY67]

When the '67 GTX 440/375 came to market, their HP manifolds were the next-best thing to the tubular-cast iron race manifolds of about 1963, pre-Max Wedge. But they would not clear the power brake booster. Headers were known for leaks and poor fit, generally, so the cast iron items were desirable from that point of view.

As I recall, the Chrysler HP manifolds dyno'd about 10 horsepower less than the tubular headers, but without all of the negatives of headers. AND a good bit more power than the normal log manifolds of '67, too.

In trying to quantify rated horsepower of Chrysler B/RB V-8s, starting with the 252/.390" lift cam, then going to the 256/260 "standard cam" in '66, then the 268/284 cam and 1.74" exhaust valves (440/375 in '67 and 383/335 in '68) . . . it seems there was some "sandbagging" in some of the ratings. Which NHRA seemed to "factor" into higher ratings, sometimes. The 256/260 and 1.74" exhaust valves jumped the 383 2bbl from 270 ('66 252/.390) to 290 in '68 (256/.425") with Carter BBD 1.56" 2bbl carbs. Looking at the road test performance of the '65 413/340 and 413/360 engines vs. the '66 440/350, the '66 440 was putting more power to the tires than either of the 413s did. Especially when correcting for gearing and weight (by my calculations). More than just the additional 27 cid might indicate, everything else being the same.

I need to find two road tests, one of the '65 300L and the '66 Chrysler 300 440 TNT (which had the 256/260 cam in '66 and rated at 365 horsepower). Then checking a '65 426W 426/365 roat test, too. I believe that more than just cam specs changed between '65 and '66, too.

Just some thoughts,
CBODY67

 

[MEV]

What would be some good recommendations on a carb I could get the most power from. I currently have a summit 750 carb on right now modified engine (aluminum heads, mild comp cam, forged aluminum pistons, forged steel crank, stock exhaust manifolds)

1475 CFM Gen 3 Ultra Dominator Carburetor
This is the ONLY carb for any 440, nothing else will work. Your engine will make exactly 561.899 horsepower.

 

[70bigblockdodge]

1475 CFM Gen 3 Ultra Dominator Carburetor
This is the ONLY carb for any 440, nothing else will work. Your engine will make exactly 561.899 horsepower.

View attachment 431196

Thanks I needed that.