Carb advice wanted....

[C500]

Hi guys,

I'm currently having the original 440 in my '69 rebuilt, and after some input on a good brand/size of carb from those with experience....

Engine has new new JE pistons, 30 thou over, Edelbrock CH4B intake, HP cast iron manifolds, mild cam upgrade Crower HDP271 (thanks Ron!!) gross lift 486/496, 906 stock heads, -10 crank grind, Johnson topline lifters (thanks Bob  ) 3.23 rear.

This is built as a street cruiser. 750 is the optimal carb size?? Looking for reliability and tunability on a carb. Vacuum secondaries over mechanical (dp)

Cheers,

Duncan

[myk]

Ron would suggest the Proform 750.  I've been thinking about that or the Fitech.  Can't decide...

[1974dodgecharger]

get fitech fuel injection....

[myk]

I dunno man.  I like the idea of the Charger being a brutal, yet simple sledgehammer that's picked up a few tricks; but not too many...

[68CoronetRT]

Fitech all the way. Carbs are so stubborn.

[RallyeMike]

Injection is nice but I'd rather fix a basic "stubborn" carb on the side of the road than injection.

[Back N Black]

Injection is nice but I'd rather fix a basic "stubborn" carb on the side of the road than injection.

I agree, i have pulled carbs apart on the side of the road and back on the road in 20 min. If the FI fails your on the back of a tow truck.

[John_Kunkel]

Injection is nice but I'd rather fix a basic "stubborn" carb on the side of the road than injection.

Not me, that's what tow service and credit cards are for.

[stuubi]

If yuo're gonna run it on street only and some occasional "signature on the road",i would go with 600-670 vac Carb.You will love the throttle response,easy cold running without choke,and good manners on highway.
700-750 will give you some 15-25hp more but difference in basic driving is to be seen unless,you tune it right or have someone who knows,tune it to you.
Yes the stock Thermo was something 780-800cfm but on primaryside,it was/is equal to 570-650 size carb primaries.

(This opinion comes from my own experience,last late-Summer i tuned 22 cars either Holly,or Edel/Carter carbs.From De Tomaso 414cid to stock -64 Chevy truck.And on raceday,from 14sec bb and sb motors to 500 Pro Stock)

OTB carb is never great or perfect,it takes some tuning to get it right,but many have been in the "it will run"-ballpark.
Both Holly and Ede have been in the need of more or less tuning,
when tuned correctly,they will be about as good as FI...almost.
Response is immediate,no bog or bang,from 30mph to 80mph it will go on tiptoe.And step on it,it will roar on instant and pull as long as the engine can.But it takes some presise tuning with wideband to get it right.Yes,timing need's to be tweaked also..And you will see difference when you floor it from dead stop.Cars that never spinned tire,started to roast them...

Edel is easier to tune,faster to tune but Holly will run exelent if tuned correctly.Allmost 50-65% of cars i have tuned with Holly,power valve need to be changed,acc squirter will be changed and pump cam needs to be replaced.
On Edel,rod's will be swapped and pump need's some tuning.And some jet changes on both carbs..

rpm x cid
----------  equals your carb size.
3456


so let say you run mostly on 800-4500/5000rpm on your 440 motor.So the formula would go:5000x440 divided by 3456 will give you answer 636-This means that in theory,at 5000 rpm,your engine need's only 636cfm to breathe.

Drop the rpm to 4500 and you will get 572.91 =573cfm...
5500rpm and 700cfm.

So,,shoot for 600 to 670 and you will like it.

Yes,,,it will make more TOP power with 750 but,on average from 800-4000 it will kick 750 all day long...


Before i put my Charger to garage to transfom,i swapped 750carter from 383 away,and bought Holly Avenger 570 on it.After some minor tuning(did not have that wideband at that time) it was a blast to drive!No hesitation,and i ran 110mph on highway,and when i floored it,it started to gain speed so...

New 383 is going to be much meaner so it will have bigger carb than 570,but i will run it on dyno with 570 just for fun

[C500]

Thanks for all the responses guys,  Does anyone here have any first hand experience with FiTech, never heard of them before? Looks like a good system, but personally I like the carb idea.... tuned properly!

[Brass]

If you have a manual or an auto with more stall, I would go with a mechanical secondary.  Vacuum is probably fine for a cruiser though.

[ws23rt]

To me a big part of the fun with our old cars is how they were when new.

I get the interest in making these old cars more like what we have grown used to for drivers.--- I feel it too.

When one updates one system in a 46 year old car it only addresses that one system.

As new our chargers ran just fine as they were built in the day and gave many miles with little trouble.

Some in this hobby could care less how the car performs. To them it's all about fit and finish.

For those that want a new world car with an old world skin.  Stevearino of this site has done very well at bringing the two together.

Am I alone in thinking that advice to move to FI is not helpful for questions about carbs??  

[birdsandbees]

I love my old car because I only ever needed a pocket knife to get it home... Carb all the way for me..

[Just 6T9 CHGR]

A few years ago I went from a slightly modded 750 vac sec Holley (Pro-form main body (dominator style)) to a 800cfm Edelbrock Thunder series carb with electric choke.  Could never get the Holley to lessen the rich, eye burning fuel smell at idle....the lack of a choke was getting annoying on cold weather starts

The eddy worked flawless for me pretty much out of the box....adjusted choke & fuel mixture and that was it...no rod changes etc.

No stumble, no hesitation off idle or when secondaries kick in....eye burning is still there but Id estimate its better by at least 50%...I attribute the rest to the cam overlap.

This is on a fairly mild 440 with 9.3:1 comp and 915 closed chamber heads, stock intake & stock exh manifolds...

[ws23rt]

I love my old car because I only ever needed a pocket knife to get it home... Carb all the way for me..

  I like the way they look and the way they drove.  Not to mention all the memories of being able to limp home when needed with a few simple tools as you mentioned.

If for example my new challenger came to a stop on the side of the road.  I would of course open the hood and have a look.  It's a routine I grew up with.
The truth is unless steam is coming from under the hood I would have no reason to even lift the hood.

[XH29N0G]

If you have a manual or an auto with more stall, I would go with a mechanical secondary.  Vacuum is probably fine for a cruiser though.

I am thinking the same thing.  If it were me, I would lean toward 750 rather than 650 because I tend to like the idea that it could run a little better up top.  It will be important to set up correctly.  I am using an A/F gauge and like it because it helps me with fine tuning, but I know the old ways of tuning also work.

[68CoronetRT]

Thanks for all the responses guys,  Does anyone here have any first hand experience with FiTech, never heard of them before? Looks like a good system, but personally I like the carb idea.... tuned properly!

Yes, Its about 100x times better than any carb I ever messed with. I love bumping the key and idling at whatever I want it to on the first crank. I love being able to restart the car in any weather condition,regardless of heat soak. It has more power now than ever. I never have to change a jet ever again, do that on the fly. No more stinking clothes at the end of a trip.

Plus the ultimate, happy wife happy life and she can actually enjoy the car now without stinking of raw fuel.

But hey, its not for everyone.

[Brass]

Thanks for all the responses guys,  Does anyone here have any first hand experience with FiTech, never heard of them before? Looks like a good system, but personally I like the carb idea.... tuned properly!

Yes, Its about 100x times better than any carb I ever messed with. I love bumping the key and idling at whatever I want it to on the first crank. I love being able to restart the car in any weather condition,regardless of heat soak. It has more power now than ever. I never have to change a jet ever again, do that on the fly. No more stinking clothes at the end of a trip.

Plus the ultimate, happy wife happy life and she can actually enjoy the car now without stinking of raw fuel.

But hey, its not for everyone.

Just not smelling of fuel all the time would be worth it.

[myk]

I like the smell of fuel, oil, plastic, vinyl and rubber; the hallmark scents of a muscle car.  I used to put my clothes in the trunk of the Charger so I could enjoy the muscle car scent even when I wasn't driving the Charger.  Hell, if someone marketed this particular scent I would buy it and wear it proudly.   

As for carb vs EFI, it's a difficult question for me.  The benefits of EFI are obvious, but the simplicity of a successful carb set up is also appealing.  And hey, it's not as if the Fitech users aren't having any setup/tuning issues either.  Just look around this site or on the intrawebz....

[C500]

I like the smell of fuel, oil, plastic, vinyl and rubber; the hallmark scents of a muscle car.  I used to put my clothes in the trunk of the Charger so I could enjoy the muscle car scent even when I wasn't driving the Charger.  Hell, if someone marketed this particular scent I would buy it and wear it proudly.   

As for carb vs EFI, it's a difficult question for me.  The benefits of EFI are obvious, but the simplicity of a successful carb set up is also appealing.  And hey, it's not as if the Fitech users aren't having any setup/tuning issues either.  Just look around this site or on the intrawebz....

Good call... I might try a Fitech unit in a couple of years, but will get running with a new carb for now. Will go the 750 for the top end.

Vacuum secondaries, looking like Proform or Edelbrock are the carb of choice for Mopar users here... 

[myk]

I've had my Edelbrock 750 for a while now and I am not a fan.  Cruising different Internet boards show that many people feel the same way, calling them Edel-bogs instead.  I want to switch to a Holley or Proform 750 with vacuum secondaries soon.  I'm worried about the more complicated tuning process with those carbs but it can't be any worse than the Edelbog...

[C500]

To me a big part of the fun with our old cars is how they were when new.

I get the interest in making these old cars more like what we have grown used to for drivers.--- I feel it too.

When one updates one system in a 46 year old car it only addresses that one system.

As new our chargers ran just fine as they were built in the day and gave many miles with little trouble.

Some in this hobby could care less how the car performs. To them it's all about fit and finish.

For those that want a new world car with an old world skin.  Stevearino of this site has done very well at bringing the two together.

Am I alone in thinking that advice to move to FI is not helpful for questions about carbs??  

Heh heh, good point... although food for thought with the EFI, carb it is for now.

[firefighter3931]

Hi Duncan,

Good to see the build coming together 

My buddy Dennis has almost the exact same build using the HDP 271/CH4B/HP manifolds and I recommended the ProForm 750 street series carb for his combo. The car runs fantastic and even gets 15mpg on the hwy cruising at 60 mph. 


Ron

[Charger_Dart]

If your interested in a Proform 750, I have a nice used 67213 that I was getting ready to list on Ebay but would rather sell it to another member here. PM me if your interested.
Mike

[C500]

Hi Duncan,

Good to see the build coming together 

My buddy Dennis has almost the exact same build using the HDP 271/CH4B/HP manifolds and I recommended the ProForm 750 street series carb for his combo. The car runs fantastic and even gets 15mpg on the hwy cruising at 60 mph. 


Ron

Thanks Ron... do you know if your buddy has the vacuum or mechanical secondary?