All Big Six Clifford intake an carb questions

Relates to all big sixes

Stella85

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Been to busy to work on the engine lately an thought of some ideas over the last couple months listening to some of you about the Clifford dual Weber intake if I understand that would be more of a high rpm performance setup so if I have the intake already what do you all think about put two one barrel carbs on that intake instead of the two webers
I was told a lot of stuff about plenum size an stuff before an to be honest most of that is over my head
 

THE FRENCHTOWN FLYER

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I use the Clifford 2 x 4 intake on a hot rod and I love it. With two Autolite 2100s it is very tractable, a real stoplite-to-stoplite killer. My hot rod has a 2500 RPM stall converter and 3.50 gears.

I also have one on a drag car and like it there for a moderate bracket race engine - not an all out race motor. It had a single 4V on it previously and regardless of the size of 4V I tried the 2 x 2 outperforms it.

I think two one barrels will also work well and would have no qualms about trying it.
 

Stella85

Well-known member
I am sorry I guess I should have mentioned I am trying to build a good torque truck for using pulling trailers an working on a farm
So I am looking for lower rpm performance
 

Firepower354

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Besides the initial movement, towing/industrial use, revs end up closer to 3000 than 1000, IMO.
Unless running an extreme overall gear reduction, it'll have to rev a bit.
I'd suspect that cutting the intake for a split 2v setup, would be a good combo.
 

Toph1821

Active member
I saw that same intake and was planning on using weber 32/36 carbs. When I contacted clifford about it he told me it would not work on my 240 with smaller carbs, but never fully explained why. I know it's more of a high rpm set up, so maybe with the smaller carbs you would end up with too much plenum and the insufficient air flow through that large of a manifold would cause problems with the mixture? I'm just starting to dive into the science of manifolds so any correction on that comment is more than welcome
 

Stella85

Well-known member
I asked the same thing about the 32/36 carbs an found out not to try
An decided to stick with the 38/38’s
But now I was wander about making a riser plate (adapter plate) to fit two one barrels on the intake instead if their would be an benefit over the dual 38’s
I imagine it would give better performance over a single one barrel carb but would it work with the plenum size also I think that the two 38/38’s might be more than I need
 

Toph1821

Active member
I asked the same thing about the 32/36 carbs an found out not to try
An decided to stick with the 38/38’s
But now I was wander about making a riser plate (adapter plate) to fit two one barrels on the intake instead if their would be an benefit over the dual 38’s
I imagine it would give better performance over a single one barrel carb but would it work with the plenum size also I think that the two 38/38’s might be more than I need
We're you given a reason as to why the progressive carbs won't work? I agree with your thinking that smaller carbs would offer better perform better for a truck motor, but that was the line of thinking that drew me to the 32/36. Small small primaries for in town and large secondaries when I get on the highway
 

Blairsville Ed

Well-known member
I can’t speak to a dual carb manifold but I do have a 240 with a Holley 5200 carb. That’s the Holley version of the Weber 32/36. I’ve also tried the Weber 38/38 and it does have more pulling power than the 32/36 but it will drop your mpg.
Stuffing the plenum made a huge improvement in pulling power, particularly at 60 mph when I encounter a hill. I can maintain speed without down shifting.
 

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Stella85

Well-known member
I was wandering about using the Clifford dual 38/38 intake which uses two two barrels an would be a high rpm performance enhancement
An using it with two one barrel carbs which in my mind would give better performance over a single one barrel but would mellow out the higher performance of the two 38/38’s an give a engine for a working farm truck for pulling on back roads an some on the highway
My worry is would the one barrel carbs work with the plenum volumes of the intake
 

Firepower354

Famous Member
A pair of 1v carbs, opened to the point of providing the desired torque, should not be appreciably different than staged 2v carbs.
Two 38/38 synchro-open will be worst case. A lot of venturi area for the airflow.
The big plenums, are going to provide a weak signal to the carbs. Wrong tool for the job. Same as the prior thread.
Yes, it will certainly run, and with a stick, have some degree of drivability. But, it'll be "soggy", need clutch slipping and throttle blipping, to get enough excess pump shot to make it to the cylinders.


One view of exaggerated plenum effect:
Directly inputting a positive signal, provides immediate response.
Add a foot of 1/2" hose, minimally delayed/muted response.
Put a sealed 55 gallon drum between the mouthpiece and noisemaker.
SWNL0254.jpg
 

CNC-Dude

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I think one problem with the Clifford intake Is a fairly large plenum volume and runner size also, compared to a more stockish plenum and runner size of an Offy intake for instance. Trying to tame the engine by using smaller carbs but having a performance oriented intake probably wont come close to offering the desired results you are seeking. There are inserts that fit in the floor of 4V intakes that compensate for that. Brodix makes them and so does Aussiespeed. So you may have to further modify the Clifford along with smaller carbs to increase the signal strength at lower speeds to get low RPM street manners to satisfy your driving needs.
 

THE FRENCHTOWN FLYER

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Where the heck were these when i was looking for intakes… i bet this would work real good with two sniper 1100s… oh well… i think im set on modding my aussie speed intake for efi anyway… just have to decide if im gonna use an aftermarket ecm or the stock one
Look closely; those intakes are not for a Ford 300. They are likely for a Mopar six.


I had a college buddy who used that 2 x 1 intake on a '62 Valiant. It was a peppy, albeit ugly, little machine.
 

pmuller9

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I think I am just going to get an offy intake an put a two barrel on it or a small four barrel on it with the efi exhaust the problem I am facing now is how to heat the intake
Look into getting the Aussiespeed intake manifolds


 
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