Which carb for strong 440?

[Duey]

Ron, Neil, others,

Going to go firm on new carb and have narrowed it down to three:

1. Holley 4150 HP - 830 cfm, mech sec, annular boosters
2. Pro-Form - 850 cfm, mech sec, down-leg boosters
3. Quik-Fuel - 850 cfm, mech sec, down-leg boosters

Given the info below, is there anything that would (money aside, $650 / $550 / $600 US for the above respectively) make me decide to go one way vs another? 

For some reason I'm leaning towards the Pro-Form, not just because it's $550...I know that annular boosters will help with the lower vacuum the .509 currently gives, but I may well move to the Engle cam anyway.  I'm pretty sure any of these carbs can be nicely set-up.  My intent is to bring the motor in to the dyno to tune it when I get it all together.

The combo is currently: 

440 +.030, 2355 10.5:1 pistons, Holley SD manifold, 346 heads (2.14-1.81 stainless valves, 3-angle seat, backcut intake valves, 75 plunge cut & ported and unshrouded), .509 MP, 3800rpm stall converter, 4.10 SG rears

Considering future upgrades:

Indy or Eddy heads, and Engle KV-3 cam with ductile iron rockers.

Intended use: I am looking to move beyond the Eddy TQuad and don't mind spending a bit of time tuning for what will be an occasional cruiser and street/strip car.  I want to make sure the carb I get now will support decent power to potential beer-can head levels.

Thanks for helping with the final choice!

Cheers,
Duey

[firefighter3931]

Hi Duey 

My holley 750dp with the proform main body worked better on the dyno than the holley 850dp if that means anything. There was only a 5hp difference but it (proform 750) felt sharper on the dyno. There's not a whole lot of difference between those carbs inmo...i'd bet they're all pretty close. The quickfuel 850 would probably be my choice and you could allways slap a 4hole spacer underneath it for increased signal to the boosters....if you feel it's too soft down low. With the better heads you're planning for in the future, it'll be a good match. I've got a couple of carbs you're welcome to try on dyno day :

(1) Proform 750dp (830 cfm)
(2) Holley 850dp mildly modded with jet extensions, notched floats

* Both are 4 corner idle

Ron

[Duey]

Hi Duey 

My holley 750dp with the proform main body worked better on the dyno than the holley 850dp if that means anything. There was only a 5hp difference but it (proform 750) felt sharper on the dyno. There's not a whole lot of difference between those carbs inmo...i'd bet they're all pretty close. The quickfuel 850 would probably be my choice and you could allways slap a 4hole spacer underneath it for increased signal to the boosters....if you feel it's too soft down low. With the better heads you're planning for in the future, it'll be a good match. I've got a couple of carbs you're welcome to try on dyno day :

(1) Proform 750dp (830 cfm)
(2) Holley 850dp mildly modded with jet extensions, notched floats

* Both are 4 corner idle

Ron

Ron, Rodger that!  Thing is I'm coming home in 6 weeks and I can order a carb through Summit to a buddy's APO here in Afghanistan and get the thing tax free, duty free with a really good exchange...so sooner decision is better...maybe the proform body in the HP DP was why I was leaning towards proform.

Does the proform by itself not have 4-corner idle...now I'm thinking QuickFuel or Pro-form...maybe the QF 850 and like you said a 4-hole spacer...still can probably fit that under the hood with a drop-base cleaner, given that I'm running the Holley SD manifold?

Hmmm....hit "Buy Now" on the Quickfuel 850? 

Thanks, Ron! 

Duey

[firefighter3931]

Duey,

Well looking at the descriptions of both carbs it appears that they're identical other than the name. Both use billet base plates and billet metering blocks. The quickfuel carb even uses a proform mainbody (radiused venturi's/no choke horn/downleg boosters).  The nice features other than the billet stuff is the adjustable air bleeds and 4 corner idle....which both have btw.  Your call on which one to get, they're basicly the same carb from what i can see. 

With a drop base air cleaner you should have no problem clearing the stock hood. Does yours have the flat or bulge hood on it ? K&N makes a very nice 1.25in drop base assembly with the flow thru top. Summit: knn-66-3040

Heck, buy the proform carb and put the savings toward the aircleaner.

Ron

[Duey]

Ron, I hadn't noticed up close that the QuikFuel had a Pro-form main body...well, why not get it from the horse's mouth...i.e. the Pro-Form 850?

As an aside, saw the K&N Xtreme drop filter...also saw the Moroso 4" unit that drops 1 3/4", p/n 65925...only 2 3/4" above the flange...even less than the 2 7/8" above the flange that the K&N is.  Do you think that 1 3/4" is too much drop?  I kind of like the look of the Moroso 4" filter unit better than the K&N...never been much of a K&N fan.

Thanks,
Duey

[firefighter3931]

Do you think that 1 3/4" is too much drop? 
Thanks,
Duey

With a std (non-hp) carb that has a chokehorn...i'd have to say yes. But, these modded carbs (proform/quickfuel) don't have a choke tower so it's not really an issue. The problem with drop bases and stock carbs is the horn comes too close to the lid and chokes off the primaries. That is why those flo-thru tops work so well with stock carb/drop base combos.

As long as it (moroso) clears the stock hood, i don't see a problem....from the description you gave it should work 

Ron

[Ghoste]

Do you think the flow through's are a waste without a choke tower then?

[firefighter3931]

Do you think the flow through's are a waste without a choke tower then?

Hard to tell because every engine's cfm requirement is different. I have one for mine even though the carb has no chokehorn...but i do have a 1.25in dropbase aircleaner assembly. The drop base creates a wall that the air hits and has to travel over on it's way to the carb. This is bound to create some restriction. How much does it compromise the airflow ? Having the top open just allows for another path for the engine to draw air. The more air the better....at least that's my take on it.

Take a look at the pic below. This is the Moroso 1.75in drop base that Duey was referencing above. There's a definate wall that the air will have to follow/climb to reach the carb throat. Does it create some restriction ? Probably....maybe...who knows ! 

Ron

Ps. On a related note: I remember speaking with a tech at the company that manufactures those trick ram air underhood systems and he told me that they don't sell anything with more than a 1.5in drop base. According to him they were too restrictive. Here's a link to that site...nice stuff ! 

http://ramairbox.com/

[Ghoste]

My drop base isn't nearly that deep but I have a choke horn to contend with.  I wonder if that may be compounding some of my other tuning issues as well.  For the price of the flow through, I suppose as you say it isn't going to hurt.

[Duey]

Ron, I think i'll go with a nice moroso gold-anodized 3" unit (drops 1.5 IIRC) vice the ultra-deep 4" offset filter...also not sure the offset wouldn't bang against the carb bowl on the "short end" of the cleaner. I like the idea of good airflow, but I'm just not too fond of the K&N eXtreme look.  i'm not worried about the old K&N vs air element question as I would not be putting on much mileage anyway and wouldn't be driving in any sand storms...

Cheers,
Duey

[Ghoste]

I'm not too crazy about the way they look either but my underhood area is already a mess.  Beginning with a previous owner who pianted the engine bay black, my car has already been Chevy-ized enough that I never open the hood anywhere but at home or the strip when I have to so...

[Dan T]

I'm not too crazy about the way they look either but my underhood area is already a mess.  Beginning with a previous owner who pianted the engine bay black, my car has already been Chevy-ized enough that I never open the hood anywhere but at home or the strip when I have to so...

I did the best I could under the circumstances that I had. I bought the car when I was 16, and If I hadn't, it would have already been crushed. If you didn't like the black paint, noone has stopped you from correcting it in the last 8 yrs!! For what you paid, you shouldn't complain!!

[Ghoste]

Slow down Dan.  First off, I thought you said it was painted before you got it.  Second, I have put a lot of money and time (not to mention adding two kids into my routine) into the car and paint has been moved waaaaay down the list.  Thirdly, the Chevy comment only referred to the black paint, everything else that has happened under the hood has been my doing (or undoing?)and I've never pretended otherwise.  It isn't a show car underhood, it's form follows function.
Oh, and welcome to the site.

[Duey]

Ron, just did the deal with Summitt.....Pro-form 850, a whole buch of nickle-plated AN fittings and hose (don't like blue and red stuff), fuel feed with press guage, regulator (have a HV Carter pump at home), 1" phenolic 4-hole spacer (if req'd ), etc...oh and a complentary set of summit fender protectors! Woo-hoo! 

Cheers,
Duey

[firefighter3931]

Ron, just did the deal with Summitt.....Pro-form 850, a whole buch of nickle-plated AN fittings and hose (don't like blue and red stuff), fuel feed with press guage, regulator (have a HV Carter pump at home), 1" phenolic 4-hole spacer (if req'd ), etc...oh and a complentary set of summit fender protectors! Woo-hoo! 

Cheers,
Duey

Nice score...congrats ! 

What about the aircleaner ?

Ron

[CFMopar]

Howd you get the free fender covers! 

[Ghoste]

By buying several hundred dollars worth of parts. 

[Duey]

By buying several hundred dollars worth of parts. 

Yup, Ghoste...that would be about it...   $20 of plastic for shelling out 'bout $700-ish for the goodies... LOL

Ron, I just remembered, I've got that black painted Moroso bit you gave me last time I was by...I think I'll actually go ahead and get the K&N X-stream top lid to top that bit off...don't want to miss out on all the airflow that will be going through the engine...can't exactly recall the config, but if the lid isn't quite right, then I'll go and get the whole X-stream assembly (in black...the red's a bit off for me...)

May be getting a second round too, ARP head fasteners and the Fel-pro 1205, and some other bits...I'm looking forward to getting all the bits together then running the beast on Sean's dyno...I'll use that opportunity to tune the beasty and the pro-form carb...should be jetted decently, but I figure might as well make the effort to max the engine's tune while I have the motor out of the car.! 

Cheers,
Duey

[firefighter3931]

By buying several hundred dollars worth of parts. 

Yup, Ghoste...that would be about it...   $20 of plastic for shelling out 'bout $700-ish for the goodies... LOL

Ron, I just remembered, I've got that black painted Moroso bit you gave me last time I was by...I think I'll actually go ahead and get the K&N X-stream top lid to top that bit off...don't want to miss out on all the airflow that will be going through the engine...can't exactly recall the config, but if the lid isn't quite right, then I'll go and get the whole X-stream assembly (in black...the red's a bit off for me...)

May be getting a second round too, ARP head fasteners and the Fel-pro 1205, and some other bits...I'm looking forward to getting all the bits together then running the beast on Sean's dyno...I'll use that opportunity to tune the beasty and the pro-form carb...should be jetted decently, but I figure might as well make the effort to max the engine's tune while I have the motor out of the car.! 

Cheers,
Duey

Duey,

That sounds good and while you're at it get a set of ARP intake manifold bolts. The small boltheads are much nicer to work with, especially with the aftermarket intake manifolds. Ya, The Moroso aircleaner i gave you has a nice drop base....forgot all about that. All you really need is a descent filter or the K&N filtertop if you want more air. I think you're on the right track with the flo-thru filtertop. 

I bet you're looking forward to dyno day....that's actually a lot of fun.  One other small suggestion while you're ordering parts; Think about a rev-limiter. Solid cams luv to rev and this engine will get itself in trouble real easy. The heavy bottom end really shouldn't be pushed much past 6k if you want to keep it together for awhile.

Ron

[Ghoste]

On the topic of rev-limiters, are there any you guys recommend people stay away from?  There are known good ones out there of course but have any of you run across a brand that's crap?

[Duey]

Ron, now I've got the bug...what better way to limit revs then to get an MSD 6-AL? DOH!

Okay, I'll only spend $500 more buckaroos...honest...that's it...then I'm stopping! Yessiree! **insert Dr. Evil "Riiiiiiiiiight!" voice here**

Don't forget, Ron...I'll still be hobbled by the .509 cam and iron heads, even if they are ported and relieved with big valves...

I specifically refrained from also adding an Engle KV-3, ductile iron rockers, solid lifters to the combo...maybe I'll get those if I get some Indy-EZ heads? LOL

I still think Paul (doctorpimp) is going to out-do me with his MPFI! he he he.....

Cheers,
Duey

[firefighter3931]

Ron, now I've got the bug...what better way to limit revs then to get an MSD 6-AL? DOH!

Good plan....Summit has a rebate right now on MSD stuff. Time for a 6al, blaster 2 coil and some 8.5mm superconductor wires. 

Sorry to hear you're not upgrading to the Engle solid, but you've got the stall and gear to make the 509 work well. Don't throw away that vacuum can though !! 

Ron

[Duey]

Ron, now I've got the bug...what better way to limit revs then to get an MSD 6-AL? DOH!

Good plan....Summit has a rebate right now on MSD stuff. Time for a 6al, blaster 2 coil and some 8.5mm superconductor wires. 

Sorry to hear you're not upgrading to the Engle solid, but you've got the stall and gear to make the 509 work well. Don't throw away that vacuum can though !! 

Ron

Ron, still doing the two-phase plan....

phase 1: SD manifold, 2.14/1.81 valves, ported heads, pro-form 850, TA 10", 4.10 SG....see how she does...looking for 350-375 at the rear wheels.

Phase 2: Indy EZ heads, KV-3 solid, full 3" TTI w/X-pipe...I think that'll be 425-ish rwhp and nrrd some eriuos traction...may have to move the shackles inboard and stick on some 295 drag radials to even come close to staying hooked up... 

Cheers, Duey

[firefighter3931]

Ron, now I've got the bug...what better way to limit revs then to get an MSD 6-AL? DOH!

Good plan....Summit has a rebate right now on MSD stuff. Time for a 6al, blaster 2 coil and some 8.5mm superconductor wires. 

Sorry to hear you're not upgrading to the Engle solid, but you've got the stall and gear to make the 509 work well. Don't throw away that vacuum can though !! 

Ron

Ron, still doing the two-phase plan....

phase 1: SD manifold, 2.14/1.81 valves, ported heads, pro-form 850, TA 10", 4.10 SG....see how she does...looking for 350-375 at the rear wheels.

Phase 2: Indy EZ heads, KV-3 solid, full 3" TTI w/X-pipe...I think that'll be 425-ish rwhp and nrrd some eriuos traction...may have to move the shackles inboard and stick on some 295 drag radials to even come close to staying hooked up... 

Cheers, Duey

Phase 1 sounds fine. You're gonna be traction limited at this power level....be prepared for smoke, and lots of it. 

The power projections seem reasonable. 

Ron

[Chryco Psycho]

you can buy a stand alone MSD rev limiter as well for $100 or so