42 DCNF's on a Mopar 440
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42 DCNF's on a Mopar 440
Hi People, I am a new B here and Hello to you all , I came here because I picked up on an Old Thread that was talking about weber DCNF's but didnt want to add to that thread even though I read it in depth and was a tad confused as it was getting a Tad Technical, there were a few members chatting away and a Chap called enigma57 who I seemed to know alot about it all was quite involved also, I didnt feel comfortabale sending a PM to him as he doesnt know me, I am fom the UK by the way and Hi to you all
This is my concern please >>
I have a few sets of Weber DCNF's as I run them on my Essex V6 capris >>
I have a spare set here that I will also overhaul >>>
I also am messing around with a Jensen interceptor of mine with a 440 mopar and have rebuilt the engine more or less standard, it has around 9:1 compression and a mildish Cam, I have also mated a 5 speed Manual Gearbox to it just for fun and my friend has an Offenhauser inlet manifold that will fit the 440, this manifold has 3 x 2 inlets ports at 42mm diameter, and he said I could have it but the deal is I buy him what he wants, here is the Manifold here >>
My question is, does anyone know if these Carbs I have would work OK on the mopar 440 engine if I go ahead and buy it from my friend, I realise that I will need to try different Chokes, emulsion tubes jets etc but would I be wasting my time trying to get it to perform? it is only a street car and for fun but I am unsure of the technicalities of the CFMs etc and wondered if anyone could shed any light on this, the manifold is obviously not and Independant runner and I would have prefered to use one of those with 4 x 42 dcnfs but it doesnt seem available, I love the 42 DCNFs on my essex V6 but understand that is an IR manifold and am always confused with surely the idea is to have one carb choke per cylinder, and when they put Tri carbs on a V8 always seem to be an unbalance in my eyes but I am not really a Carb intake Knowlegable type of chap, so was looking to see if anyone can advise if I am wasting my time even thinking of doing this please.
Thank you for reading my post
With my regards to you all in advance for any comments and time for me
Many thanks
Grant
This is my concern please >>
I have a few sets of Weber DCNF's as I run them on my Essex V6 capris >>
I have a spare set here that I will also overhaul >>>
I also am messing around with a Jensen interceptor of mine with a 440 mopar and have rebuilt the engine more or less standard, it has around 9:1 compression and a mildish Cam, I have also mated a 5 speed Manual Gearbox to it just for fun and my friend has an Offenhauser inlet manifold that will fit the 440, this manifold has 3 x 2 inlets ports at 42mm diameter, and he said I could have it but the deal is I buy him what he wants, here is the Manifold here >>
My question is, does anyone know if these Carbs I have would work OK on the mopar 440 engine if I go ahead and buy it from my friend, I realise that I will need to try different Chokes, emulsion tubes jets etc but would I be wasting my time trying to get it to perform? it is only a street car and for fun but I am unsure of the technicalities of the CFMs etc and wondered if anyone could shed any light on this, the manifold is obviously not and Independant runner and I would have prefered to use one of those with 4 x 42 dcnfs but it doesnt seem available, I love the 42 DCNFs on my essex V6 but understand that is an IR manifold and am always confused with surely the idea is to have one carb choke per cylinder, and when they put Tri carbs on a V8 always seem to be an unbalance in my eyes but I am not really a Carb intake Knowlegable type of chap, so was looking to see if anyone can advise if I am wasting my time even thinking of doing this please.
Thank you for reading my post
With my regards to you all in advance for any comments and time for me
Many thanks
Grant
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Re: 42 DCNF's on a Mopar 440
Do you know if the throttle bore spacing of the manifold matches the carb?
Re: 42 DCNF's on a Mopar 440
Hi Mr Cleveland, yes the bore size and spacing on the Carb is exactly the same as the manifold, both are 42mm port holes in the manifold and the Carb, they match perfectly with the spacing also Mr Cleveland Man, so yes they match in all respects
Re: 42 DCNF's on a Mopar 440
Hi, Grant! Welcome to Speed Talk! Rec'd your PM and will respond there.
As you are aware, the choke size, emulsion tubes, accelerator pump cam, jetting and air corrector size for a much larger displacement engine fitted with 42 DCNF carbs on a plenum style intake as opposed to a smaller displacement engine with an isolated runner intake will be considerable. I have experimented along these lines and can give you a baseline jetting from which to work. Will forward via PM.
Best regards,
Harry
As you are aware, the choke size, emulsion tubes, accelerator pump cam, jetting and air corrector size for a much larger displacement engine fitted with 42 DCNF carbs on a plenum style intake as opposed to a smaller displacement engine with an isolated runner intake will be considerable. I have experimented along these lines and can give you a baseline jetting from which to work. Will forward via PM.
Best regards,
Harry
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Re: 42 DCNF's on a Mopar 440
That is a cool intake,good luck with the project!
"69"satellite,3900lbs,8-71,edel victor heads,I/C,446cu.in W/gas 1250 carbs
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Re: 42 DCNF's on a Mopar 440
That is not a very good intake compared to the Edelbrock six pack manifolds.
The Offenhoauser mqnifold is divided lengthwise which will give very short runners and uneven suction.
A properly timed manifold will give even suction.
Erland
The Offenhoauser mqnifold is divided lengthwise which will give very short runners and uneven suction.
A properly timed manifold will give even suction.
Erland
Re: 42 DCNF's on a Mopar 440
Nick, how's your workload in the coming months? Sure would like to have you do the machine work on my Inglese DCNF casting if you can work it in.
Best regards,
Harry
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Re: 42 DCNF's on a Mopar 440
With lengtwise divider, 3 barrels supply 4 cyliners and I see the runners makes uneven lengths so, not ideal.Erland Cox wrote:That is not a very good intake compared to the Edelbrock six pack manifolds.
The Offenhoauser mqnifold is divided lengthwise which will give very short runners and uneven suction.
A properly timed manifold will give even suction.
Erland
How about cutting into the deviders below the carbs? It would make a difference, however maybe not good enough.
Other than that- with common plenum, I'd say the carbs are up to fulfilling the engine's needs (in reasonable Hp/ rpm area).
The 6- barrells are common Chamber and was designed With middle carb comming in at full throttle, right?
Great Inglese- manifold! Never seen that one. Always looked at the IDF's too small for IR setups on big cube V8's. (However- they suited tha smaller Ferraris, Fiats and Maseratis well.)
I know there used to be a 44 IDF, but I have never seen one. Those should be good for some Hp on a 300+ CUI V8. 42's come up for sale now and then and the 40's are the only ones to buy new OTS.
What size are these, Nick?
How to turn GURU in an instant.....
Re: 42 DCNF's on a Mopar 440
As Nick noted, these are extremely rare castings, Caprimaniac. Other than the raw casting I have here and pics of Nick's similar casting which was machined and of the one pictured on this thread utilizing EFI throttle bodies, I have only seen photos of one other.Caprimaniac wrote:Great Inglese- manifold! Never seen that one......
My hobby is crafting one off Weber induction setups for odd applications where there are no intakes available to mount them. I have a couple sets of Weber 42 DCNF carbs here and have long intended on working up an IR intake to mount a set of them on a small block Chevy engine, to replace the original 235 inline 6 in my '57 Chevy.
After I found that there were actually intakes cast for this purpose at some point, I contacted Jim Inglese and asked him if he had any or knew where I might locate one. Jim told me that back in the late '70s before he sold the company which bears his name to the conglomerate which now own CompCams and Lunati amongst others...... He had Winters Foundry cast 'about a dozen' of these intakes. Only a handful were machined and delivered before he sold the company. And only recently, a few castings (some machined and some not) have surfaced. These were likely either prototype castings or the few remaining on pallets in the Inglese warehouse (company now owned by CompCams et al, not Jim's current company) and I was fortunate to snag one that a fellow had sitting in his shop for some while in a small town up in Minnesota.
These are IR intakes designed to mount (4) Weber DCNF carbs in a row on small block Chevy engines. The 42 DCNF (depending on choke size utilized) will support 300 - 350 cu.in. displacement on IR intake. For larger displacement engines between 427 and 500 cu.in. displacement, these carbs would have to either be recalibrated and used on a plenum style intake......
Or...... If you are a really wild and crazy carb guy with masochistic tuning tendencies, you can take one of the early Edelbrock, Offy, Weiand or Mickey Thompson cross ram intakes (the one piece castings like the Edelbrock X-1 or later XC-8, not the lower Z-28 style with removable top plate) and modify it to mount (8) DCNF carbs...... (4) per side by milling off the plenum tops, welding in divider walls to make the intake function internally as an IR intake and then weld on new tops to mount (4) DCNF carbs on each side, both throttle bores of each DCNF supplying a single, isolated runner feeding each cylinder. 16 throttle bores feeding 8 port runners. Lots of fun to balance and sync.
Here are some pics of the unmachined Inglese DCNF casting I have here......
Note Winters Foundry 'snowflake' cast near #8 runner in above photo.
And here is a pic of one that has been finish machined and polished (the one that inspired me to begin my search a few years ago)......
One issue that must be dealt with in placing one of these intakes in service is that Jim designed the intake to be used with an offset drive distributor due to the limited clearance at the rearmost carb mounting pad. So I'll either have to do something similar or use a front-mount distributor setup. I have located one of the Laughton front mount distributor covers made in the '70s, but so far have not located the internal distributor drive pieces, so have not made a deal with the fellow who has it.
In answer to your question regarding sizing of the EFI throttle bodies mounted on the intake setup Nick posted...... I have seen DCNF replacement throttle bodies having throttle bore sizes up to 45 - 46mm in the DCNF configuration. And since there is no choke (main venturi) in these EFI throttle body replacements, they should flow close to what a carb having same sized chokes would....... Enough flow to support a stroker small block up to 450 cu.in. displacement on IR intake.
Best regards,
Harry
P.S. >>>> Erland is quite correct in his assessment of the early 360 degree Offenhauser intake design. These are a single plane open plenum design having a center divider running front to rear, so each divide plenum half supplies the 4 cylinders of the bank on its respective side of the engine. As compared do a 180 degree dual plane intake, the Offy has some advantages and some disadvantages inherent to the design. In order to provide even fuel distribution, some internal mods need to be performed and the end carb mounting pads must be relocated closer together to center on the paired port runner entries at either end.
Considering the 360 degree intake manifold's architecture and the big block MOPAR's port layout, the flow requirements of Grant's 440 engine and the revised calibration of the Weber DCNF carbs he will be running...... We will either set it up on straight throttle linkage (all 3 carbs opening simultaneously)...... Or on progressive linkage with the end carbs as primaries and the center carb as secondary in order to better balance flow and ensure equal fuel distribution (the opposite of the way a dual plane 180 degree tri-power intake is usually set up).
Fortunately, the compact design of the Weber DCNF carbs allow mounting them as closely as 4.75 inches center to center, so with 3 of them in a row, the end carb spacing can be tightened up to 9.50 inches on center. The internal mods address the flow imbalance at #5 and #7 port runners caused by the engine's firing order and will require specifically sized and positioned notches opened up where the center divider meets the plenum floor as was done by MOPAR with their early 273 cast-iron 4bbl intakes circa 1965 - 1966 which were a similar design to the 360 degree Offy intakes. Those mods are a part of the discussion Grant and I are having regarding his Offy intake for big block MOPAR.
The 440 MOPAR having a front mounted distributor...... There is also the opportunity to add a separate external 'jumper port' connecting #7 and # 8 runners at the rear of the Offy 440 MOPAR intake much as Zora Arkus Duntov did with the single plane Holley 'Z' manifold design of the early '80s. These were a divided single plane Street Dominator style intake which had the added rear interconnecting port cast in to correct the #5 /#7 fuel distribution/firing order issue. Here are pics of the small block MOPAR version showing the passage interconnecting the rear runners......
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Re: 42 DCNF's on a Mopar 440
Working through a mountain of work at the moment. I have you covered just need to get caught up first. I have you on my list.
Re: 42 DCNF's on a Mopar 440
42 DCNFs were also used on the Maserati 4.7 and 4.9 liter engines. These engines redlined at 5500 RPM. DCNFs on a Mopar BB are far too small. Good luck.
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Re: 42 DCNF's on a Mopar 440
Seems to me the 1.650 throttle size X8 would be equal to a 625 dual carb set up?? A total of 1250 cfm?
Not small at all.
Not small at all.
GURU is only a name.
Adam
Adam
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Re: 42 DCNF's on a Mopar 440
I don't think that was the restriction but I haven't sat down to study those motors. I would think the carbs would have enough flow for less than 300ci. I plan to go 45mm or slightly bigger on mine for a healthy 406ci SBC.
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Re: 42 DCNF's on a Mopar 440
Those engines were rated at 5500 not red lined there. Previous were rated at 6000. That tells me the insurance companies lent a hand.......JCR wrote:42 DCNFs were also used on the Maserati 4.7 and 4.9 liter engines. These engines redlined at 5500 RPM. DCNFs on a Mopar BB are far too small. Good luck.
The L-88 Chevy was rated at 4500 if I remember correct but made steam from 5500 to 7500 rpm and 120 more HP without headers.
GURU is only a name.
Adam
Adam