Help with carburetor selection

[mopar2]

Hi I'm wanting to get rid of the Edelbrock on my Charger. Pretty much stock 440 HP, /03 over, stock deck height, all MSD, Edelbrock RPM performer intake, HP manifolds (considering headers), don't shoot me but .484 purple cam, 2600 stall and 3.55 gears. I'm looking at these two on eBay, please advise me if I'm on the right track and if not what should I be looking for Thank You.

http://www.ebay.com/itm/350499064837?ru=http%3A%2F%2Fwww.ebay.com%3A80%2Fsch%2Fi.html%3F_from%3DR40%26_trksid%3Dp5197.m570.l1313%26_nkw%3D350499064837%26_sacat%3DSee-All-Categories%26_fvi%3D1&_rdc=1


http://www.ebay.com/itm/360400996054?ru=http%3A%2F%2Fwww.ebay.com%3A80%2Fsch%2Fi.html%3F_from%3DR40%26_trksid%3Dp5197.m570.l1313%26_nkw%3D360400996054%26_sacat%3DSee-All-Categories%26_fvi%3D1&_rdc=1

[Plumcrazy]

For a street car you're better off with a vacuum secondary carb.
Something like this.

http://www.summitracing.com/parts/HLY-0-80770/

[RECHRGD]

When I changed out my vac. secondary 750 Holley to 750 Holley D.P..  the difference was like night and day...for the better.  That's on a street driven automatic car with a mildly built 440.   Bob

[Brass]

When I changed out my vac. secondary 750 Holley to 750 Holley D.P..  the difference was like night and day...for the better.  That's on a street driven automatic car with a mildly built 440.   Bob

I agree with this entirely.

[Chryco Psycho]

me 3

[Plumcrazy]

From Holley's website.

"Use of a mechanical secondary carburetor should be limited to use on a lighter vehicle. The weight of the vehicle should be less than 3100 lbs,full weight.
Full weight includes fuel,water and driver.
If the vehicle meets the above weight requirement and has a manual transmission with a low first gear plus a 3.73 or lower gear ratio,you can use a mechanical secondary carburetor"

Your car comes nowhere near meeting these requirements.

[RECHRGD]

From Holley's website.

"Use of a mechanical secondary carburetor should be limited to use on a lighter vehicle. The weight of the vehicle should be less than 3100 lbs,full weight.
Full weight includes fuel,water and driver.
If the vehicle meets the above weight requirement and has a manual transmission with a low first gear plus a 3.73 or lower gear ratio,you can use a mechanical secondary carburetor"

Your car comes nowhere near meeting these requirements.

I read all that crap before purchasing the D.P..  I took the advice from the many experts on this site and am glad I did.  My car has 3.55's with a Gear Vendors O.D..  I can floor the pedal from a dead stop with no bog or ill effects at all, except for the tire smoke.  I like knowing that when I mash the pedal that the secondaries are actually opening and there's no denying it when your pinned to the seatback.  Bob

[firefighter3931]

I LUV double pumpers 



Ron

[mopar2]

The Edelbrock I have now, I cannot get rid of the off idle stumble, I've changed springs, metering rods, jets and fuel squirt-er. I have had several people tell me get a  Holly. So I looked at Summit and it's like Holly overload LOL they look a lot alike but what's right for me.

Firefighter you say you love double pumpers are either of the carbs here  right for my combination?

Recharged, Brass and Chryco Psycho is the 750 I posted here what you're talking about?

Plumcrazy I see what the description is but with the low vacuum 10-12 with my .484 purple cam I'm concerned about vac secondary's.

Is the 850 too big?

I really appreciate the input from everyone as I knew this would be the place to get the help I needed, Thank You.

[mopar2]

Also looking at the carb plumcrazy suggested is  Dual Fuel Inlet the same thing as double pumper?  

[RECHRGD]

The Edelbrock I have now, I cannot get rid of the off idle stumble, I've changed springs, metering rods, jets and fuel squirt-er. I have had several people tell me get a  Holly. So I looked at Summit and it's like Holly overload LOL they look a lot alike but what's right for me.

Firefighter you say you love double pumpers are either of the carbs here  right for my combination?

Recharged, Brass and Chryco Psycho is the 750 I posted here what you’re talking about?

Plumcrazy I see what the description is but with the low vacuum 10-12 with my .484 purple cam I'm concerned about vac secondary’s.

Is the 850 too big?

I really appreciate the input from everyone as I knew this would be the place to get the help I needed, Thank You.

Also looking at the carb plumcrazy suggested is  Dual Fuel Inlet the same thing as double pumper? 

The #4779 750 is what I have.  You can use the 850 but you may lose some of the street manners for only a small gain that may only be seen at the track.  No, a dual fuel inlet is not the same as a double pumper.  It simply provides a separate fuel inlet for both the primary and secondary bowls.   Bob

[firefighter3931]

This is the carb i would run on a build like yours : http://www.summitracing.com/parts/PRO-67213/

The 284 cam is OK but there are much better modern profiles available these days. If you stay with the 284 definately consider a set of headers...the engine will run/breathe much better. The old school "284" has a lot of overlap and doesn't like restrictive (manifold) exhaust. 



Ron

[mopar2]

I have been hesitant to change the cam out (because of my screw-up picking 484 purple), the engine has a little over 4k miles on it. I know there are better cams but in the same boat as the carburetor, which one?

Power/torque for the money (I'm not against doing both, more what order) change the cam or headers to help the purple cam?

Thanks Rechrgd fixing to look that up.

Fierfighter is that a double pumper? I see now dp are Dual accelerator pumps. Just trying to get it right this time as the whole cam and carb choice I made before was wrong for my stall and gears.

[firefighter3931]

Yep, that Proform 750 is a mechanical secondary (double pumper) carb. 

Ideally you should do both the headers and carb but if you could only do one....the carb would be my first choice 

With that cam you will see good results with some ignition tuning ; 18-20* at idle and 36-38* total all in by 2600-2800 rpm for best performance. 




Ron

[Chryco Psycho]

I would recommend the Proform over the Holley the Proform is simply a better carb it is more tunable & can be a far more accurate & responsive carb even right out of the box

[mopar2]

Thanks Ron That is exactly where I have my timing now

The carb is being changed especially now that I have ya'll recommendations

The other was more headers vs getting rid of the purple cam, when picking a new one what should I go with?

I like the car, just my lack of knowledge when picking parts I feel really shows up and would like to get the Carb, cam exhaust to work together.  I want the 3.55 as I drive wherever I go, just had the trans done this past winter and feel the engine is not where it should be. Thank again.

[mopar2]

I would recommend the Proform over the Holley the Proform is simply a better carb it is more tunable & can be a far more accurate & responsive carb even right out of the box

going to look at now Thanks

[mopar2]

This is the carb i would run on a build like yours : http://www.summitracing.com/parts/PRO-67213/

The 284 cam is OK but there are much better modern profiles available these days. If you stay with the 284 definately consider a set of headers...the engine will run/breathe much better. The old school "284" has a lot of overlap and doesn't like restrictive (manifold) exhaust. 



Ron

Already put this one on my Summit list  Now with this set of headers http://www.summitracing.com/parts/HOK-5903-1HKR/ 
I  just need some guidance on wither to change the cam and which one if there's no working with the one I have in there

[Chryco Psycho]

The Cam is OK , headers would gain you more . What exactly are you looking for , what powerband , mostly street / cruising ?
Lunati VooDoo has modern profiles that will give more vacuum & response while maintaining the powerband if you want to stay with a hyd profile .

[mopar2]

I cruise local car shows about a 75 mi radius. My complaint is throttle response and It does not break the tires loose as I feel it should. While I do not race, I never take it out without doing ":several" WOT test, either from a dead stop, rolling or just going down the hwy to a show. So no I don't race but I have a very heavy foot LOL

[mopar2]

I do not want to start over rebuilding the thing but more than happy to address some simpler mistakes I made with part selection. When the day comes to start over I will follow the advice I've seen here for a high torque street engine. For now would appreciate this forms advice to get all I can without starting over

[Chryco Psycho]

the 484 cam really cuts in about 2000 rpm so you need a taller converter than that to get into the powerband before the load is on the engine , the Lunati 60303 or even the smaller 60302 may be a good fit for a hyd that will give better low end response & a good powerband up to 550 range

[mopar2]

Yes more stall and more gear is what the cam needs. Just want to make sure I have what I have running (tuned) as best I can. Not changing gears or trans mission, I think they are right for my usage. With carb and headers, if it's not where I feel it should be, I will change the cam on ya'll advice that I would feel the difference , just stopping at not going any deeper as it runs ok just not quite there for what I think it should be.

So cam input is welcome as I will save it on my Summit account just in case I need to change it. So please advise on cam selection and wither you think I would feel a difference in the car.

Thanks Chryco I'm going to go look at those cams you posted now. 

[firefighter3931]

I agree with Neil (Chryco) : the 303 Lunati cam would be a better choice but you can do a few tricks to make the 284 cam more responsive. The first thing i would do is get that carb and a set of  headers. Even the Headman 1 3/4 in tube would help with scavenging and ex gas reversion.

Second thing i would do is open up the timing cover and degree that cam in on a 102* intake centerline. This will wake the motor up on the low end of the RPM spectrum and give it more off idle grunt. 

You have enough stall and gear as long as the cam is properly dialed in. 

Good job on the ignition curve...that's where it needs to be ! 



Ron

[mopar2]

Thank you, I put the Lunati 303 on my summit list Thanks again!!!!!!!!!  

This is shad tree maniac-in if you ever heard, my purple cam was in straight up a couple weeks ago without a dial I put a 8* bushing advancing it. Cylinder pressure went from 130-135 to 170-175, car ran concededly better. That's when I started taking seriously about how many people told to get a better carburetor, as to how much more was my tuning off?

Carburetor and headers are next for sure, birthday is this month

These are 1 7/8 you mentioned 1 ¾ are the ones I have saved too big?
http://www.summitracing.com/parts/HOK-5903-1HKR/ 


I can't thank ya'll enough I can't hardly wait to get my new carburetor  

[Brass]

I would recommend the Proform over the Holley the Proform is simply a better carb it is more tunable & can be a far more accurate & responsive carb even right out of the box

I wish I had know about this carb when I got mine!  I bought a Holley 4778 (700 cfm) and had it re-jetted which is good - but I think I would like that Proform better than the Holley.  You probably will too.

[mopar2]

I would recommend the Proform over the Holley the Proform is simply a better carb it is more tunable & can be a far more accurate & responsive carb even right out of the box

I wish I had know about this carb when I got mine!  I bought a Holley 4778 (700 cfm) and had it re-jetted which is good - but I think I would like that Proform better than the Holley.  You probably will too.

When the builder delivered my car the first thing he said "if this was my car I would get rid of that Edelbrock"


Looking at cam specks the Lunti has a little more lift and less duration, with more lobe separation. I take it this build more cylinder pressure creating more torque?  

[ChargerST]

What about a Proform 750 vacuum secondaries race carb? http://www.summitracing.com/parts/PRO-67205/

Is a about $100 more than the street version - worth it?

[Chryco Psycho]

I generally use the Proform race series double pump carbs no choke

[flyinlow]

Thermoquads rule!!!

OK ,just stirring the pot. 

Too many of you guys using 750DP's to ignore. The short comming of the Carters and Eddys is their accelerator pumps are limited compaired to the Holleys.
Are the modern street DP's dependable. year round?  Are the power valve and leaks fixed?

[Chryco Psycho]

we have had proforms on strokers for better than 3 years now , they sit for 6 months at least over winter , no leak issues , ifit is tuned properly or has the restirctor in the port to the power valve no issue thee either

[Challenger340]

IMO,
On an Engine Dyno, you would NOT see 10hp difference in peak power or Trq, between the old mp .484 and the lunati 303, all other parts being the same....
No wars wanted,
again IMO,
I just think you are better off adding the Carb, Headers & Tune-up as suggested, rather than going inside the Engine for very limited, if at all, gains in swapping the Camshaft.

[mopar2]

Just wanted to say Thank You all for the help 
Can't waite to get new carb and headers and report back