Photo of small six with custom three 2-V manifold?

Its still a realitivley free country, so use whatever. Enjoy whatcha do, and you cant make a bad call.

Except for downgrading to three 7448 Holleys with tiny 1.1875 venturis which will drag your peak power down, and remove mid range torque.

Peak rev range with 30.6 mm venturis on a 250 engine is 3600 rpm, and a open plenumb won't make a jot of difference.

CFM has nothing to do with improving any performance; duty cycle and venturi size govern this aspect.

The only way you can go down a carb venturi size without suffering a disapointing mid range and upper range flatness is by a higher compression ratio and a Restrictor Plate cam profile, the late Currie Industries 65 Mustang is an example; even though it had a low compression ratio, it ran on 87 octane.


With the right intake manifold, cam, and heads, you can get 350 hp from even a 289 with a box stock 4412 blueprinted 500 cfm Holley 1.375" venturi carb.

Even a 2-bbl (or especially a 2-bbl!) really likes single plane 4-bbl intake a lot better than anything Ford ever made for 1968 to 1985 2 or 4-bbls. If your very carefull, this might fit under the hood.

See http://www.hotrod.com/cars/featured/hrd ... g-fastback


http://image.hotrod.com/f/9267509+w660+ ... 8-hero.jpg
and this


http://image.hotrod.com/f/9267560+q80+r ... _large.jpg

Photo 8 of 15 | The Keith Dorton-modified 500-cfm Holley carb is the largest allowed in Currie’s Carrera Panamericana class, and it mates to an Edelbrock Victor Jr. single-plane intake with an adapter that’s hogged to match the carb’s bore size. Maximum power on the dyno was made with box-stock calibrations. http://www.hotrod.com/how-to/engine/ford-289-engine-buildup/#ixzz3ig86Xoy3 @HotRodMagazine on Twitter | HotRodMag on Facebook

The hot 289 two-barrel shown here made an impressive 352 hp at 6,700 rpm and 316 lb-ft at 5,000 rpm—on 87-octane gas—using a sensible combination of parts and preparation.



There is a very specfic combo listed here that will get you close, but it'll be like a 86 with the wildest 303 cam, and you'd probably out perform it. Due to the cam and carburation, your rev range would require some gearing more like Franks 66 Shelby replica. Its a real car, with real performance, and some real science went into getting it to do 140 mph and sub 15 second 1/4 miles. None of that data is hidden. If you run it through a simulation program, you get the same power peaks with less rpm. It is a real 7000 rpm engne with 292 cubic inches. A 306 would drg the peak power rpm down a little with the cam specs.

Basically, peak power is its related not to peak carb air flow because (as NASCAR proved), even with Winston Cup steel restrictor plate, and a little 390 cfm 4-bbl, you can make 850 hp if you compress, cam, exhaust and use the right heads the right way to underscavege a 351 Windsor or pre EFI F452 block. In a similar way, the so called production Carrera Pamaerica has been dominated by 2-bbl stock gasoline engines that absolutely can make insane power very, very cheaply. Frank Curries car in the link above is proof what can be doen on below 9.25:1 compression and 87 octane gas.


The problem with the 2150 is that they were only 1.08 or 1.21 carbs, 287 or 351-356 cfm rated Fords way. With the advent of the 1965 Clean Air Act, Ford decided the last big two barrel was the 1964 to 1966 390 2100 series "C4MF-A"prefixed Autolite 2-bbl with a 1.33 venturi, and 424 cfm.

The SAE Net Hp in the 2-bbl 400 was about 172 to 180, then down to 159 to 163hp in the restricted exhaust truck era. Rated Gross was 260. I'm picking that with the 5.0 GT 1.21 carb, you'd get to 250 hp net fairly easily. The German DIN factory net hp was about 240 in the 64 to 66 2-bbl 390, or 280 hp Gross.

The work Currie Industries did on there Mustang

http://image.hotrod.com/f/9989744+w660+ ... _right.jpg


includes a cam specification, a intkae and exhaust target air flow, an intake manifold, and it would work fine with a 2150 carb fly cut or abrasive reamed to a 1.375" venturi. Normally, any Motorcraft carb has well over 160 thou of wall thickness in the casting. With 80 thou removed around the annular portion of the venturi, you'd get to a 1.375" venturi size fairly easily, enough for over 430 cfm. If it broke through, you can expoxy it back with JB weld, and resand with emery or wet and dry. Its been done before with 5200 Holley Webers, take them out another 160 thu easily for 336 cfm, up from 227 cfm.

a stock 5200 Holley Weber, which is 23 and 27, can be routed out to 29 and 31 mm venturis and still work, as well as flow 336 cfm at 3" Hg like this one by Mercury Marc (an Aussie told him how to do it!)




Without a very specfic cam duration, exhaust and intake flow development program, you stuck with these sizes for performance

For any thing port on port, irresepctive of grouped plenumbe, assuming a 5 inch from butterfly to valve head.

Up to 1.181" or 30mm,180 hp six
up to 1.260" or 32mm, 198 hp six
up to 1.378" or 35mm, 234 hp six
up to 1.496" or 38mm, 276 hp six
up to 1.575" or 40mm, 306 hp six
up to 1.653" or 42mm, 336 hp six
Up to 1.771" or 45mm, 390hp six
up to 1.889" or 48mm, 444 hp six
up to 1.968" or 50mm, 480 hp six
up to 2.047" or 52mm, 522 hp six
up to 2.126" or 54mm, 558 hp six.

As stated, ye canne change the laws of physics" unless you play around with the exhaust flow rates, compression, and find a signifcantly better way to deliver fuel to six cylinders. They've done that at NASCAR, ACTC, and LeMans where restrictor plates are common, but they have engineers with degrees to help them. As you can see above, I'm not against CFM figures, but CFM isn't the issue, its the size of the restriction in cubic inch of engine per square inches of venturi, a critical flow dimension which has defined drag factors under Bernoulis eqautions. CFM at a carb is pressure based, with a targed air speed of about 265 feet per second for Holley carbs, 4-bbl or 2-bbl. Its really got nothing to do with anything but having a fair, common base to rate things by.

Air doesn't care about CFM. Flow net analysis defines horsepower because engineers who are good at it (and Ford Motor Company has the best engineers around bar none), they rate engines on not just dynos, but in actual real world conditions.

I think the GT40 427 Dual Quad system was the best ever non Independent runner system around. It kicks a$$. But try fitting that kind to a six in line, and it won't work.


If you want to go to 30.6 mm venturis, factor in $400 for David Vizard at APT Fast to design a new camshaft and exhaust to suit your intake system.

Then get them to grind a cam blank to suit.

Don't try an cheat physics...its too expensive.

https://www.aptfast.com/ContactUs.aspx
92507 (Riverside Weather Forecast, CA)
Advanced Performance Technology
595 Iowa Avenue, Suite C
Riverside CA 92507

Phone: (951)686-0260
Toll Free: (800)278-3278
Fax: (951)686-2831
danton@aptfast.com
 
xctasy":c5oz91vp said:
You can do this all from one supplier.

Lynx.

Lynx Auto.com.au":c5oz91vp said:
Factory 15, 35-37 Canterbury Road. Braeside, Victoria 3195. Australia

Tel:

Australian Area Code 61

(03) 9587 32 77



You take your Ford 250 2V 6 Cyl - 3 x Weber DCOE manifold, the Lynx M190 intake, https://www.lynxauto.com.au/ford-6-cyl- ... ifold.html.


m190.jpg




To hook the Holley 2300 or Autolite2100 /Motorcraft 2150 to the m190 intake, you use either three of the BurtonPower adaptors


https://www.burtonpower.com/inlet-manif ... fv450.html

Inlet manifold adaptor - DGV/DGAS to single DCOE. Ford Essex V6, SOHC Pinto, Kent X/flow OHV FV450

bp_holley_weber_inline.jpg



See https://www.burtonpower.com/media/catal ... /FV450.jpg

, or three of the WeberPerformance Lynx KC190 90 degree adaptors

https://www.weberperformance.com.au/pro ... ts_id=1115

LynxC190__DCOE_TO_holley_weber_180DEGNONinline_000.jpg



LynxC190__DCOE_TO_holley_weber_180DEGNONinline_001.jpg




LynxC190__DCOE_TO_holley_weber_180DEGNONinline.jpg


You then have to add the normal Holley Weber 5200 to Holley 2300/Autolite 2100/ Motorcraft 2150 adaptor to each to mount your 500 cfm Holley 4412 carbs.

Racer Walsh makes them and has done since the 1970's for the SOHC 1969 -1974-Pinto/Capri 2000 and 1974-2005 Lima 2300/2500 engines.


RWA1255_RACERwALSHHOLLEYWEBER5200TOH2300_A2100_M21502BBL_001.jpg


Redline makes another

Carburetor-Adaptor-Plate-2-Barrel-Holley-to-Weber.jpg


With a linakge and a proper level of jetting with reduced PVCR'S or removed power valves, Job done.

Well looks like we are starting to nail this down some now! So if Bob happens to already have that Lynx M190 intake like in Xctasy's above picture and then could get ahold of those 90 degree adapters also pictured above or maybe even make them. Then you could calculate out the size plentium (about 80% of engine capacity) and then build it out of some sheat aluminum to mount on top of the 90 degree adapters, you would have a short style tunnel ram intake to mount the 3 Holleys or Autolites on top of or many other carb's for that mater. Good luck (y) :nod:
 
powerband":1wz3qcwm said:
Any 1 know what carbs would fit w/o interference?...starting to look pretty crowded ?!?

.. that's the question, mockups I've done have linkage and parts interference issues not to mention synchronizing. Adding a plenum can add some real estate for carb choices . Removable plenum could offer differering carb configuration swapping.

'still like the idea of three small 2bbl progressives ...


haev fun

3 X 2+2

. .

simpler Tri-Port big 2bbl adapter:
.

Not progressive, but it works on my daily driver.
img/_data/i/upload/2019/03/12/20190312231332-2ad19529-sm.jpg
 
This what I am working on right now, remember this is early and I will probably change it some as I progress. I am hoping to be able to sand cast this by either finding someone with a forge or building one myself (yes I have cast metal before and built patterns, just was a long time ago).

What I am doing right now is building the pattern and laying it out, I am using 1990 Ford Escort carbs a progressive 2bbl (build by Webber/Holley), my intention to direct link all the carbs.

579cefef17324ad42d61525fdc1e4453.jpg


My pattern should basically look like the finished product except in wood :roll: I will post more when I get some more done, I am working on this right now because I decided the aluminum head is not in my budget currently and I was not sure of the availability.

The head is a '72 M head (I am going to put late model valves in it and hardened seats), and I have removed the auto choke on the center carb, will probably remove all the auto chokes and build a manual choke(s). Also my engine is a 250 I think a 200 could run just 2 of the carbs possibly (Escort is a 1.9L IIRC).

See Ya,
Mike
 
"...'90 escort carb..."
The Ford variable venturi carburettor or the replacement Weber carburetor 28/30 TLDM ?
Sounds like 1 of the last evolved carbs...
 
chad":14hjz6y7 said:
The Ford variable venturi carburettor or the replacement Weber carburetor 28/30 TLDM ?

They are Motorcraft 740 or 5740 used on the Escort/Lynx 1981-1990

See Ya,
Mike
 
lavron":2aczc985 said:

Nice. (y) :wow: :beer: :cool: :unsure:

Any carb sizes will work, but you
(Dean knowing might shall become Will ) need significant Restrictor plate style cam, exhaust and ignition spikes to get it running crisp.

But love is what I have for your setup lavron, and 62Ranchero200 and 64 200 ranchero and people who aggree/dissagree.

For everyone who says independent runner style port on carbs work, there's another who says they don't. badasscars.com is full of sarcastic bull pucky. I know. Now I'm sarcastic too.


2 barrel carbs are bigger than 4 barrel carbs
http://www.badasscars.com/index.cfm/pag ... prd440.htm
badasscars.com":2aczc985 said:
Now, I know I'm going to get the emails from guys saying that if they ran a 250 or 275 cfm 2 barrel on their car, it would Peter-out at only about 2,500 - 3,000 RPM. Well thank you Dr. Obvious's. We're not talking about running at full or max RPM here. We're talking about running around town in your average RPM range, which is usually below 3,000 RPM, so IF you are comparing apples tp apples, for normal driving, which includes gas mileage and off the line get-up and go, it is a fact that even something like a 350 cfm 2 barrel will be more sluggish and will get less mileage than a 500 or 600 cfm 4 barrel, which supports my argument that a small 4 barrel is pretty much always better for throttle response, gas mileage and off the line get-up and go power than what most would consider to be a "small" 2 barrel.


And http://www.badasscars.com/index.cfm/pag ... prd400.htm

The actual reality is the adge old Eduardo Weber IR knowledge

http://www.timsroadster.com/html/tuning_webers.html



timsroadster.com":2aczc985 said:
There are some common misconceptions about Weber IDAs. I recall when I was designing the motor for my Cobra replica I was talking to a gentleman who is very highly regarded in the industry about my carburetion options. I told him that I was considering Weber IDAs. He was very adamant that the IDAs were a poor choice and went on to explain why. For my application (a 331 stroker small block Ford) the “traditional” carburetor might be a Holley 650 CFM four barrel. This carb has 4 bores that are approximately 43mm in diameter. A Weber IDA system for the same motor might use 8 bores that are maybe 40mm in diameter. He explained that the Webers would fall flat on their faces when nailing the throttle because they would suddenly be opening up nearly twice the throttle area of the Holley 4-barrel. This, he reasoned, would kill air velocity and therefore performance.

At first glance, his reasoning seems sound. But it’s actually not, and the reasons become clear if you think about it a little bit more. A motor demands air only one cylinder at a time. In a traditional 4-barrel setup, the carb is essentially only serving one cylinder at a time, and each cylinder “sees” all 4 barrels plus the entire manifold at WOT. In essence, this is just the opposite of what the expert explained to me. An engine with conventional carb sees far more area when the throttle is nailed than an engine with Webers. Consider an IDA on an individual runner. Each cylinder only “sees” its dedicated barrel and a very short manifold runner. It certainly doesn’t “see” any of the other independent barrels. This results in a very fast-moving air charge. Torque is a highly dependent on air velocity and high velocity increases torque. Since the runner is so short, the air can get moving very quickly, increasing throttle response. There is a reason that the Weber IDA on an independent runner manifold was the carburetor of choice for race cars prior to the advent of fuel injection. It provided the best torque, and throttle response – essential for a race car.



Ask Mike1157. After removing his turbo and putting a BMW M3 six ITB EFi system on, and finding it didn't have the mid range and high end grunt of a turbo, he then found a whole bunch of leaks and other issues. Which is common with multiple delivery fuel systems.

Carbs have a progression circuit, transfer slots and idle air bleeds, and this needs to be understood.

Its why some 32/36 and 5200/62xx/65xx Holley Weber cars don't idle, while others do.

hh033annotated.jpg


That's the difference between a loose torque system and one that eats other cars. The Italians shared the info to V8 engineers that made the Maserati Indy, Ghibbli, Khamsin, Bora and Aston Martin V8 Vantage. Ask an owner of them about Mid range and low end grunt. Those owners really know how great a non Fuel injected multiple carb engine is. Jay Leno on the Khamsin is great.

The late John Wyer (Aston Martin and GT40 race engineer) drove the first AMV8 Vantage, and was amazed that it felt better than the early Bosch Injected versions.


It's all good. :nod:
 
Howdy Bob the builder.


What's needed to make 280 rear wheel horspower and well over 390 horsepower at the flywheel in a Falcon Pick-up?

A minimum of Three 50 DCO carbs with 45 mm venturis.

I.e. Six 2 inch throttles with six 1-3/4 inch venturis.

see https://www.whichcar.com.au/events/drag ... -challenge

ford-falcon-xf-ute-drag-challenge-007.jpg



ford-falcon-xf-ute-drag-challenge-engine-2.jpg


ford-falcon-xf-ute-drag-challenge-7.jpg



The Aussie Cross Flow intake ports flow worse than the Vintage In lines / Classic inlines heads do, with ports that are smaller. The only restriction to horsepower with the aloy US 250 2V head is net valve lift from the valve lengths and valve guide positions, the rocker ratio, and your carb size.

Increasing the carb venturis and Isolating the runners to make it an Independent Throttle Body ITB system takes care of idle and performance. All idle problems are high port velocity issues in our less than port on port in line sixes. The best way to crucify performance is drop down in carb venturi size.

The six Venturi size basics that work to get flywheel net horspower are these:-


For any thing port on port, irresepctive of grouped plenumb, assuming a 5 inch from butterfly to valve head.

Up to 1.181" or 30mm,180 hp six
up to 1.260" or 32mm, 198 hp six
up to 1.378" or 35mm, 234 hp six
up to 1.496" or 38mm, 276 hp six
up to 1.575" or 40mm, 306 hp six
up to 1.653" or 42mm, 336 hp six
Up to 1.771" or 45mm, 390hp six
up to 1.889" or 48mm, 444 hp six
up to 1.968" or 50mm, 480 hp six
up to 2.047" or 52mm, 522 hp six
up to 2.126" or 54mm, 558 hp six.

To get those sizes, the carb throttle HAS to be at least 1.125 times the venturi size to flow well.

It's not got anything to do with CFM...that's a falsehood. It's got to do with the shape and size of the hourglass profile, and the goal is low air speeds of in some cases less than 17 feet per second at the peak flow.
 
I C Mr. Bernoulli is back ("hour glass").
Wonder if Giovanni Battista Veeeee is gettin jealous ?
:unsure: :help:
:eek:
 
chad":2nw4l5dp said:
I C Mr. Bernoulli is back ("hour glass").
Wonder if Giovanni Battista Veeeee is gettin jealous ?
:unsure: :help:
:eek:

Bernoulli predated Giovanni.

th_bernoulli001.jpg

https://oi1215.photobucket.com/albums/c ... lli001.jpg

Neatherlands verses Italy.

As a database guy, anytime this comes up the audience sees the the spining SQL structured query Language hourglass....

bernoulli_in_sql_002.jpg


In SAE and Areonautical engineering, USA Engineering has always attempted to restrict air and preach the high air speed doctrine, to set some basic rules.

And thats all fine and good.

The Italians, expressly them, figured that low velocity reduced the drag factor of the booster venturi in the constricted air tube we call the carburettor. It has a drag factor of 0.70 to up to 0.90, which is equal to a brick shizenhauser.

cd_cx_cv_001.jpg


0.04 is state of the art, but 1.15 is as crook as an areonautical air brake.

Best production car is 0.22, best plane is 0.16, but planes have been down to 0.18 since the 1930's.

An F1 car's drag coeficient varies from 0.75 at Monza where downforce isn't as critical as top speed, where it needs to be up to 1.25 at Monaco, where its gotta stick.


In ITB systesm, the venturi constriction diameter verses the carb choke diameter and the engines cylinder size all must follow the Eudaro Weber Chart PMO Carbs use.

EW_001.jpg


When it does, the venturi booster drag factor has a Cd of 0.80 or so, and very low air speeds then produce maximum power.

Raising air speed, always hurts peak power unless you have a restrictor plate class of vehcile, where peak air flow is limited. In those instances, you have to hook into compression ratio, zero loss intake systems, and restrictor plate camshaft design that controls exhaust flow to create more vaccum.


350 to 400 bucks gives you a custom cam design. With a few extra dollars, a roller cam profile will allow any type of carb size to work best.

Down grading the carb size always hurts low, mid and high range power. Always. With extra venturi size, your fuel consumption improves if everything jet wise and accelerator pump size wise is kept within the right range.
 
xctasy":299msnbf said:
Howdy Bob the builder.


What's needed to make 280 rear wheel horspower and well over 390 horsepower at the flywheel in a Falcon Pick-up?

A minimum of Three 50 DCO carbs with 45 mm venturis.

I.e. Six 2 inch throttles with six 1-3/4 inch venturis.

see https://www.whichcar.com.au/events/drag ... -challenge

ford-falcon-xf-ute-drag-challenge-007.jpg



ford-falcon-xf-ute-drag-challenge-engine-2.jpg


ford-falcon-xf-ute-drag-challenge-7.jpg



The Aussie Cross Flow intake ports flow worse than the Vintage In lines / Classic inlines heads do, with ports that are smaller. The only restriction to horsepower with the aloy US 250 2V head is net valve lift from the valve lengths and valve guide positions, the rocker ratio, and your carb size.

Increasing the carb venturis and Isolating the runners to make it an Independent Throttle Body ITB system takes care of idle and performance. All idle problems are high port velocity issues in our less than port on port in line sixes. The best way to crucify performance is drop down in carb venturi size.

The six Venturi size basics that work to get flywheel net horspower are these:-


For any thing port on port, irresepctive of grouped plenumb, assuming a 5 inch from butterfly to valve head.

Up to 1.181" or 30mm,180 hp six
up to 1.260" or 32mm, 198 hp six
up to 1.378" or 35mm, 234 hp six
up to 1.496" or 38mm, 276 hp six
up to 1.575" or 40mm, 306 hp six
up to 1.653" or 42mm, 336 hp six
Up to 1.771" or 45mm, 390hp six
up to 1.889" or 48mm, 444 hp six
up to 1.968" or 50mm, 480 hp six
up to 2.047" or 52mm, 522 hp six
up to 2.126" or 54mm, 558 hp six.

To get those sizes, the carb throttle HAS to be at least 1.125 times the venturi size to flow well.

It's not got anything to do with CFM...that's a falsehood. It's got to do with the shape and size of the hourglass profile, and the goal is low air speeds of in some cases less than 17 feet per second at the peak flow.


Mike1157 has just made flat 12's with his 2JZE turbo

7.69@94 mph, 1.9 60’ times.
The good?....The car runs great. It runs the 1/4 mile in 12 flat, and got 23mpg on the way to the track,


mike_m_20201113_143914.jpg
 
Down, down, dwn into a 1/2 century number of post on this thread...

I can't help but think of the swarthy Itialians preceeding us each time I cross the shop w/a broom, turn a rusted nut w/(spanner) wrench right (CW) or frozen screw wrong (CW) that the defeated Brit empire (U and me both, bud) can't get by w/o these tid bits (much as I try to ignore) the hundred-yr-past-southern-europeans (shame on the thought) with tutonic sounding names (Weber) and lowly births having anything to do w/ my own top shelf endevors (I'm incorporated, after all, by god !).

Then I Do sit back, mesmerized by the spinning hour glass, and realize - I C the mechanic has put the carby on the wrong side of the motor (above). Better fortify myself w/nother 'Founders' (see Grand Rapids, MI, usa, any flavor U typically enjoy https://www.brewbound.com/news/founders ... n-rambler/ ...see last paragraph, go to co's own site) as it spins. Realize, as an ol dude, I still have the capacity to move some neurons around. Learning is a choice. But these 3 2v I would not choose in this app. Ignorance is bliss...I'm a pretty happy guy ! :eek:
 
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