4bbl carb on flathead?

[Flathead man2]

I heard even before I got on here there are people running 4bbl's on their flatheads. What would the advantage be in looks and get up and go? I'd like to run 3 94's but Im trying to figure out when I get the engine if I go that way how to get all three to work together, but I think I might go with a Holley 390 cfm 4bbl.

[4dFord/SC]

Here's mine. Runs great.

[quickchange34]

Dont use the 94s if you plan to use all three together . Use the 81s, you will be glad you did , or use a 390cfm 4 barrel.

[ford3]

3 duces are awsome looking, but the synconising problem can be a bitch, and on top of that you have to deal with alighnment problems with the off set generator bracket, you may or may not have that problem

[52merc]

4 barrel easier to tune i run a edelbrock

[52merc]

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ford 3 how are you

[ford3]

still kicking, and you?

[Ol' Ron]

The 4bl carb on a flathead is the most practical modification you can make. the engine runs on the primaries until you need more power and adds more as you need it. It also is very economical in operation and trouble free. I recommend the Edelbrock 500 cfm as it's more tunable than the 390.

[deuce_roadster]

The engine I am currently building for my 40 coupe is going to be using:
Holley 0-90470 470 CFM Truck Avenger Carburetor
for the same reason as the one Ol' Ron states.

[RKS.PA]

I've been running a 390 cfm Holley on mine for 15 years. Mounted it backwards on an Offy manifold and used slightly modified original linkage. Electric fuel pump delivers approx. 6 lbs. No regulator needed. After original set up, no adjustments needed and no more vapor lock. Mine looks like 40dFord's. I was after a reliable driver and that's what I got!!

[34flathead]

have the edelbrock 500, need the edelbrock intake and then will install.
rich

[52merc]

for 3 i will be in portland 3june then down to lake tahoe can i visit on way down

[19Fordy]

Few things beat the look of 3 carbs on a flattie. If you decide to run a 4 bbl. be aware that the OFFY intake offsets the generator mount 7/8 in. to the driver's side. Gen. pulley and fan pulley will not be "on center" with the crank pulley.

[Rock Hornbuckle]

Originally Posted by Ol' Ron

The 4bl carb on a flathead is the most practical modification you can make. the engine runs on the primaries until you need more power and adds more as you need it. It also is very economical in operation and trouble free. I recommend the Edelbrock 500 cfm as it's more tunable than the 390.

I ran a 500 cfm Edelbrock on a 256 Merc Flatty and I loved the performance.

[29AV8]

I have a 390 cfm Holley on my 8BA in my 29 roadster pickup.It really works good.
29AV8

[Flathead man2]

Thank you guys for all the great hints, I'm gonna run a 4bbl. How would the 390 win over truck avenger or vise versa? would one have more benefit over the other, I know truck avenger dont flood out, and good for offroad but where do each carb benefit the flathead?

[G32]

Thanks Ford guys!
I'm copying this thread & filing in my Ford Build Binder.
Any recommends/ comments on use with 221s,239s,255s pre or post WW2?
(i'm Pre War -1941 Dutch\Oklahoma model:::Ford Guy)
Gene Tulsa Close to old Duce Heaven

[36tudordeluxe]

Originally Posted by Ol' Ron

The 4bl carb on a flathead is the most practical modification you can make. the engine runs on the primaries until you need more power and adds more as you need it. It also is very economical in operation and trouble free. I recommend the Edelbrock 500 cfm as it's more tunable than the 390.

Yes, the EDELBROCK 500 works very well on my 276.

[Kahuna]

I run 2 of the Holley 4 bbl series 4000 "Teapots" on my 32 Tudor.
They are directly linked and run very well. The 2 X 4 manifold was cast
by Ken Austin in Oregon. I think I have the only one he ever made

[41LjH]

Go to the Holley web site and use their calculator. I believe you will find the 390 with vacuum secondaries is what flatheads need. The flathead racers in this area use a 390 and say anything else is over carburation
I use a 390 on an offey single plane. My 8BA is still pulling smooth and strong at 5K
I think a 97 flows about 75 CMF.

[Ol' Ron]

Yes, if i were to go racing, might use the 390. However the 500 Edl on a 276 when first installed got 8MPG after several tuning sessions it gets over 20 and runs better. It's a modern carb and tuning it is quite easy. However you must includ the ignition curve with it.

[52merc]

jim what made you use the t pot carbs it certainly unusal trev nz

[ford3]

hey trev, you would be very welcome, but im about 150 miles south west of lake tahoe, another 3 hours or so out of your way

[Ol' Ron]

The new Holleys and Edelbrocks run rich out of the box. fix it before you loose the rings. And go broke buying gas. The Edelbrock are beter economy carbs.

[Flathead man2]

When I do go with a 4bbl how much could I lean it out to make the engine run right but at the same time to have it run when I stomp on it? If I remember right ya cant lean them out very much and still have performance. I think generally three turns lean. I might be wrong. I'm goin to look at an engine later this month. It's a 52 merc engine 255 if I'm on the number.

[flatjack9]

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The only real way to know is to use an A/F ratio meter. If the carb is sized right for the engine, you really shouldn't need much adjustment. The idle mixture is controlled by 2 needles and 3 turns is out of the question. Cruising A/F ratio is controlled more with main jets. Again changes of 1 or 2 sizes should be all that is required. Idle, main and power circuits all have some overlap.

[ford3]

the only thing you can lean out on the carb is the idle jets, they have nothing to do with power

[Flathead man2]

thanks guys

[19Fordy]

Kahuna, That Ken Austin intake is really something very special. I bet it feels neat knowing you own the only one in the whole world. I am sure you are a good caretaker of that gem.

[Fordors]

I'm not so sure about the Edelbrock being "modern" Ron. It was introduced as the Carter AFB in 1957, later Federal-Mogul produced them and eventually Edelbrock bought the rights. Edelbrock had them built initially by Weber Carburetor, and today they are assembled by Magneti-Marelli for Edelbrock. I like the 390 Holley as a better choice for a typical street engine; the smaller venturi's will pull a stronger vacuum signal giving a better transition from idle to cruise and also have a snappier feel on the street than a 500cfm carb. Choosing between a Holley or Edelbrock is kinda like living in Chicago- Sox or Cubs? It all boils down to personal preference and experience.

[Kahuna]

Hi Trev;
I used the Teapots cuz they're cheap. No one wants them and they're of the era.

Hi Jim:
The Ken Austin deal is/was very unusual. When I first called him and asked about doing it, he said he probably could. We had several conversations over several months
and then nothing from him for almost a year, I think.
Then he called asking for an address to send me something. I gave it to him, asked him if he wanted any money (he said no) and again, nothing happened. A few months later a wooden box arrived with a manifold "mock-up" for me to check dimensions, make any changes and return. No changes were needed so I sent it back.
Maybe 2 months later the manifold arrived. On the underside of the manifold is marked
ADQ-1 (Austin dual quad #1). It is easily as good or better than anything I've ever owned. The casting is perfect, as is the machining.
Mr. Austin is a true gentleman in every sense of the word. I don't know how he's doing, as his site is down. I hope he is OK. I believe he's in his eightys. He'd been doing manifolds for over 50 years.
He also had another project that I was really interested in:
It consisted of making 24 stud aluminum heads with the water pumps cast into each head like the 21 stud engines. I could really fool alot of the "6 volt" guys then.

Regards to all,
Jim

Forgot to add:
The original agreed price for doing this was to be $ 500.00. When the manifold arrived, the bill included was $ 400.00. I called and and mentioned that we had agreed on 500.
He said no, that 400 was just fine and would not accept any more. Won't find many people like that.

[RandyZ]

PRO: The flathead runs great with the 390 properly tuned.

CON: Every dickhead is going to tell yo " they never came from ford with a 4 bbl"
I just say" No kidding and ford never used 5 speeds either thank you".

[Flathead man2]

thank ya sir

[Ol' Ron]

Yes I know they started out as Carters (1952 first year) and had many up grades along the way, Edelbrock included. Much easier to change rods. jets no so much. However the tuning kit makes it easier to find the right combination. We use an AF meter, with this it's easier to get the Power and cruse ratios in line with power and economy. Now with that said, you must follow this with changes in the distributor advanve curve. A lean mixture need more advance. Power is around 18/20 for WOT.

[lonewolf]

You should read the atrticle hotrod mag. just did on intakes they dyno tested 2x2 3x2 and 4bbls the 4bbls performed great

[wga]

Check out the WCFB. Flows in the 375 CFM range, and is ideally suited to a flat motor.
Barney Navarro, had his 4V intake made for this carb. They are easy to tune, smaller than a Holley. They were OEM on 50's Olds, Caddys, Pontiacs.
Some info from the Carb Shop website:

WCFB


The WCFB was Carter’s first attempt at a four-barrel carburetor. It was introduced in 1952. A total of 222 different WCFB models were made in the years 1952 through 1967. The WCFB was discontinued after the 1967 model year. I have seen a number of different meanings for the WCFB acronym. One employee of Carter once told me that it meant “wrought cast four barrel”; and used that terminology for years. However, a close friend who worked most of his life for Carter, chastised me for using this terminology. It seems the official Carter meaning was Will Carter Four Barrel (Will Carter of course being the inventor that started the Carter Carburetor Company). So I now use this designation when asked.

The WCFB is a “square-bore” carburetor; with three major castings: (A) throttle body (early aluminum, later cast iron); (B) bowl (zinc alloy) and (C) airhorn (aluminum).

I have been unable to find ANY Carter-published CFM ratings for any of the WCFB carburetors. However, for the purpose of argument, one may compare throttle bore size and actual venturi size of various WCFB carburetors to other models, which do have published ratings. WCFBs had approximate ratings from about 375 CFM to about 500 CFM.

The Carter WCFB was identified by a tag, which originally was placed under the drivers’ side rear airhorn-to-body screw. Various sources have attempted to positively identify WCFBs by casting numbers. This may be done in a few rare cases; but generally this is unsuccessful. While the various sources MAY be correct with their casting number tables, generally they are unaware that other carburetors may have used the same blank casting, machined in a different manner. Therefore, if one knows the carburetors identity, one would know what castings would be present; but the reverse is certainly not true. The reader should use any such tables with the proverbial “grain of salt”.

While some of the WCFB carburetors had no airvalve, most of the WCFB carburetors have the weighted airvalve to prevent the secondary from flowing until the engine demand was sufficient to require flow from the secondary. There were also a very few WCFB units that had vacuum controlled secondary. These units, like the vacuum controlled AFB carburetors, were (and still are) exceptionally troublesome. Carter discontinued this design after a couple of years.

While there are many categories of parts on the WCFB that look as if they should interchange; two in particular that give many enthusiasts problems are metering rods and floats. The metering rod is an extremely precision device. Most enthusiasts look only at the metering diameters; but do not realize that the LENGTH of the metering step is not the same for all rods. Carter utilized at least a dozen different step length profiles. When interchanging rods, unless one is deliberately changing the step length, one should compare the step length profile of the replacement to the original rod. The floats used in the WCFB are a double pontoon arrangement, connected by an arm. THERE ARE SEVERAL DIFFERENT FLOATS, WHICH APPEAR TO THE NOVICE AS IDENTICAL! Maximum buoyancy of a float occurs when the flat surface of the float arm is perpendicular to the fuel inlet needle. A method used by Carter (also Rochester in their 4G series, and Stromberg in most of their two barrel series) to adjust the fuel level was to move the height of the arm where the arm was soldered to the pontoons. Failure to observe this difference in floats may lead to carburetor flooding issues. Even if the float arm is bent to achieve the specified adjustment, the buoyancy

[Flathead man2]

That was kind of my question, cause if you look at the intake ports in the block and the manifold, you'd think how is this gonna work? Big carb for small engine. You'll burn up rings for sure. But the big question is how well do they run leaned out like that with a 4bbl?

[51 MERC-CT]

Originally Posted by Flathead man2

That was kind of my question, cause if you look at the intake ports in the block and the manifold, you'd think how is this gonna work? Big carb for small engine. You'll burn up rings for sure. But the big question is how well do they run leaned out like that with a 4bbl?

The 4bbl. 390 on mine runs on 2bbl's most of the time as do just about all others. So when when you are tuning it, for the most part you are really tuning a 2 bbl. carb.

[Flathead man2]

ok that makes since. he he

[Richard in Florida]

Originally Posted by Ol' Ron

Much easier to change rods. jets no so much.

Having changed jets several times I can tell you it's not that hard. All you to do is lift off the top of the carburetor with the carburetor still on the engine.

The jets are at the bottom of the bowls and easily changed. Replace the top and you're done.

[B. Ginzo]

Never seen 2-4's on a flathead looks great.

[itsa52]

I have a basically stock 52 Merc.. Not sure but I think it has been bored .040.. I have picked up 2 different 4GC carburetors for it.. one is off a 1964 300 Buick with the aluminum throttle plate,, The other is off a 55 Caddy.. Make any difference which one I use?

[wga]

The 55 Caddy is probably a WCFB about 375 or so CFM . Small in size. Looks right at home
on a flatty. Fits the Navarro 4V intake like they were made for each other.

http://www.thecarburetorshop.com/Car...arburetors.htm

[Pete]

I agree that the 390 is a good carb for a mostly stock flathead.
They have TWO big disadvantages for a traditional hot rod though. They don't make much noise at WOT. This is why a lot of guys run loud pipes to compensate.
Also, they do not look traditional. You might as well have a 350 Chev. sitting under them.
People nowdays will put a lot of money into modifying a flathead say to 268 or
276 ci, put on 3 Stromberg 97's or 48's and never hear the song it sings at 5500 rpm because they are actually afraid of the noise..
It isn't a race engine but it sure sounds like one.

[itsa52]

No Carter,, both Rochesters

[scooder]

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Originally Posted by itsa52

No Carter,, both Rochesters

Do they both have the small bolt pattern where they bolt onto the manifold?
The early ones had a small bolt pattern, these line up with the holes in the flathead 4bbl manifold with no adaptor. Not sure when Rochester changed the pattern.
If one of yours has the Small pattern, I'd go with that one. Just because it fits nicer and looks nice and neat. If they both have the bigger pattern, I'd go with the later Buick one, take advantage of a few years development.
's what I'd do.
Martin.

[Walt Dupont--Me.]

Well, I've always been the odd ball, I know the right 4bbl runs good but to me it just don't look right on a flathead. I've run everything on my 40coupe with 276, right now I'm running 4 97's direct linkage, carb set up by Mad Max, 18mpg on secondary roads, I'm sure I'd get 20mpg on turnpike, of course I'm running a T-5 with 3:50 rear gears. Runs just as smooth as one carb, If you figure CFM 4-97's is over 600cfm. Any body want a ride? Walt

[scooder]

Mr itsa52,
If you do end up using a four bbl on yours, if you got stock loadamatic ignition, you'll need to swap it out for an ignition with mechanical advance,
the stocker has no mechanical advance and won't work properly if not connected to the correct port on the correct type of carb.
There are some (teapot and a few Carter's) fitted to pre 57 (I think) Ford engines, the Rochester carbs you have Will not have the correct port/vacuum signal for the loadamatic.
Martin.

[Andy]

I would go with the newer carb. I had an early Caddy and it did not have velocity flapper in the secondaries. It was difficult to give full throttle without it bogging.

[itsa52]

Thanks Andy good info and reason.

Scooder,, we are talking about Rochester 4 BBls, they won't fit on a Merc manifold.. And I have an older Mallory Distributor I will be sending to Bubba to set up, and run that.. As different choices, I agree the multiple 2 barrels look much better especially on the 30 and 40's Fords.. Not that much of an issue to me on the later Fords and Merc, which is what I have.. Also 1 4bbl is a whole lot easier on my pocket book than several Strombergs

[scooder]

When I said " early bolt pattern Rochester 4bbl will fit on flathead 4bbl manifold" I'm talking about the 4bbl manifolds made for a Flathead. Offy, Navarro, edelbrock, Fenton and so on. These all come/came with small early Rochester 4bb, WCFB, Stromberg 4bbl and so on, no adaptor needed.
Not talking about bolting it on to a stock Merc manifold.
There's a folk on here running the early (1952) Rochester 4 jet on flatheads, they work fine.
Sorry for confusing the issue.
Martin.

[36tudordeluxe]

I like the Edelbrock also, as others say easy to tune and great support. Mounted backwards in order to utilize stock linkage,

[Ol' Ron]

Your best carb for that 53 Merc is a 2GC Rochester. Have the intake bored to match the carb bores.

[39topless]

With the 390 Holley, you will need a riser tower to get the carb and linkage above the top radiator hoses. With the air cleaner included, make sure your have enough clearance for the hood. Also, the stock carb linkage will need to be modified. I was able to use the stock choke linkage but the accelerator will need a new cable type. The choke and accelerator are on the opposite sides of the carb compared to a stock carb. I was able to keep the stock gas pedal with some engineering to the route and cable fittings. Good luck

[scooder]

Topless, it's a late Merc engine so carb/radiator hose interference won't be an issue.
As for linkages being on opposite sides, one solution is just turn the carb around. I used to think that should be wrong, never really had a good reason to think why, just sounded wrong. There are a number of folk running carbs arse about face with no problems or issues. I'm convinced now that it's fine to run it "backwards", when I get a 4bbl inlet for mine, it'll have the carb (52 caddy, Rochester 4jet) turned round.
Martin.

[39topless]

Originally Posted by scooder

Topless, it's a late Merc engine so carb/radiator hose interference won't be an issue.
As for linkages being on opposite sides, one solution is just turn the carb around. I used to think that should be wrong, never really had a good reason to think why, just sounded wrong. There are a number of folk running carbs arse about face with no problems or issues. I'm convinced now that it's fine to run it "backwards", when I get a 4bbl inlet for mine, it'll have the carb (52 caddy, Rochester 4jet) turned round.
Martin.

Damn!!! Why didn't I think of that? Turn it backwards and invert the two carb levers. The obvious sometimes ain't.

[4dFord/SC]

Originally Posted by scooder

Topless, it's a late Merc engine so carb/radiator hose interference won't be an issue.
As for linkages being on opposite sides, one solution is just turn the carb around. I used to think that should be wrong, never really had a good reason to think why, just sounded wrong. There are a number of folk running carbs arse about face with no problems or issues. I'm convinced now that it's fine to run it "backwards", when I get a 4bbl inlet for mine, it'll have the carb (52 caddy, Rochester 4jet) turned round.
Martin.

That's the way my Holley 390 is hooked up.

[butchbov]

Originally Posted by Kahuna

I run 2 of the Holley 4 bbl series 4000 "Teapots" on my 32 Tudor.
They are directly linked and run very well. The 2 X 4 manifold was cast
by Ken Austin in Oregon. I think I have the only one he ever made

Now that's awsome How does it rrun?

I run a 1956 Carter WCFB on my .060 over 8BA & it's just right.

[Kahuna]

Butchboy
They run real well, give good mileage and, so far, are trouble free. The jetting had to be changed, but that's all.
Thanks
Jim

[Talkwrench]

Your motor looks real nice Bob.

[AnthonyG]

Edelbrock 1403 manual choke or 1404 auto choke the way to g.o

[Richard in Florida]

Originally Posted by AnthonyG

Edelbrock 1403 manual choke or 1404 auto choke the way to g.o

The 1403 is electric choke, and the 1404 is manual choke.

From the Edelbrock web site:

[34PKUP]

Originally Posted by Richard in Florida

The 1403 is electric choke, and the 1404 is manual choke.

From the Edelbrock web site:

Picky, Picky, Picky- I have a 1404 with an electric choke. Does that make it a 1403 ? For that matter if I have a 1403 with no electric choke, does that make it a 1404 ?

[AnthonyG]

I went through the same research process when contemplating a 3 x 2 set up. The score on my post was about the same as this thread indicates.
1 - 3x2 has the biggest cool factor but also the biggest PIA factor setting up.
2 - Close to the same cool factor but much easier set up 2 X 2 either 94's or Stom's .
3 - Edelbrock great for the 4 barrel set up in the 500 cfm if your Flatty is modified a bit to take the higher cfm.
4 - Holley 390 for closer to stock engine lower cfm works better.

Mine is a medium modified 8BA and I was running an Edelbrock 500cfm and it ran great. I still have it and will use again in the future I suspect. For a little more cool factor I have tried a 4 barrel to 2x2 adapter from Speedway and went with the 2x2 with 94's. This setup with direct linkage was an easy set up and runs well. Wasn't sure about using the adapter but it runs great and lets carbs sit extra high which is a great look also.

[Ol' Ron]

I like the idea of the Edelbrock carb, because of it's ability to be tuned for both power and economy. However the ignition curve had a majoe affect on both and is sometimes ignored. I realize astecits are a big factor inthis hobby.

[boogie]

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Originally Posted by Ol' Ron

Yes, if i were to go racing, might use the 390. However the 500 Edl on a 276 when first installed got 8MPG after several tuning sessions it gets over 20 and runs better. It's a modern carb and tuning it is quite easy. However you must includ the ignition curve with it.

On your combo what pri. rods/jets/springs and secondary jets worked for you?

Thanks
boogie

[37pickupproject]

Originally Posted by Ol' Ron

I like the idea of the Edelbrock carb, because of it's ability to be tuned for both power and economy. However the ignition curve had a majoe affect on both and is sometimes ignored. I realize astecits are a big factor inthis hobby.

How does your ignition curve compare to a stock distributor? How much timing are you running?

I'm going for a speedway intake and edelbrock 4 bbl for my 296ci. I was thinking of sending my crab to Bubba to have it rebuilt and converted to 12v electronic. What do you suggest I do for igntion?

[GreenMonster48]

Originally Posted by boogie

On your combo what pri. rods/jets/springs and secondary jets worked for you?

Thanks
boogie

They used set up #11 in the manual. .083 jets and the metering rods that came with the carb. I used this same set up on the flathead in my avatar and it's working great. I ordered the whole jet/spring kit, but you might be able to get away with just ordering the jets.

[jimTN]

What was the original application for the 390 carb?

[scooder]

Jim,
The 390 cfm Holley is purely aftermarket I believe, so no original application.
Can't say for definite, just from vague memory.
It is in my opinion a tad on the small side even for stock flatheads. The 465 cfm seems ideal. If you haven't got it, get JWL's book. This will give you the dyno numbers.
Given the choice of 390 Holley or 500 edelbrock, I'd go with the edelbrock. Can't argue with Richard's findings.
Martin.

[russcc]

Anyone have experience running one of Barney's original 4 barrel manifolds with the Holley 390 CFM ? I was looking for one of his original ones because I believe he always had the best designs and casting quality. Did Navarro engineering make a 4 barrel manifold for the 59AB ?

[wga]

Ran a Navarro 4V intake on a 59AB in my 47, with a WCFB. Nice combo. Still have the intake, an original.

[JonC]

Originally Posted by Walt Dupont--Me.

Well, I've always been the odd ball, I know the right 4bbl runs good but to me it just don't look right on a flathead. I've run everything on my 40coupe with 276, right now I'm running 4 97's direct linkage, carb set up by Mad Max, 18mpg on secondary roads, I'm sure I'd get 20mpg on turnpike, of course I'm running a T-5 with 3:50 rear gears. Runs just as smooth as one carb, If you figure CFM 4-97's is over 600cfm. Any body want a ride? Walt

Walt I want a ride, I'll say please if it helps.

[38convsedan]

I’m considering Edelbrock intake and Edelbrock 500 for my 8BA.
Can you walk me through a how to and components needed?
How are the accelerator and fuel lines modified?
Thanks in advance!
Steve

[38 coupe]

38convsedan, you are running an 8BA yes? Are you currently running the stock distributor and carburetor? If yes, be aware you will also have to change the distributor when you go away from the stock carburetor.
The 500 cfm four barrel is probably larger than your engine will like.

[Pete]

I am surprised the "traditional" police haven't been all over this thread. It has been here a LONG time....LOL

Electronic fuel injection works far better.

[aussie merc]

Seems to me that the overriding factor here is carb sizing .Get that right and it all seems to work , its all about air flow thru the carb giving the correct signals cam and compression have some bearing but in the end not that much just need to match air flow with the sweet spot ..

[tubman]

I think you're right. I had a 390 Holley on a 276" Merc with a MAX-1 cam, and Offenhauser heads about 25 years ago. it seemed about right. I just wish I knew then what I know today. I'll bet it would have been even better.

A couple of years ago, I tried adaping a Quadrajet from a 3.6 liter Buick V6 to a 258 ci Flathead, that also had heads and a MAX-1. It did not work at all. I think it was the disparity between the size of the throttle bores on the Q-Jet to those on the Sharp 4-BBL manifold I was using. It was so bad that I abandoned he project almost immediately before I ruined a fresh engine.

[38convsedan]

38 Coupe,
Yes…I’m running an 8BA..
In reviewing posts on the subject it looks like there are 390 and 500 schools of thought.
Those in the 500 camp comment on ease of tuning…
I understand the 4 bbl will require an updated dizzy..,

[jimTN]

What is wrong with the Rochester carb, simple and no metering rods to worry with.

[38 coupe]

Since I'm not planning to run a four barrel on a flathead I can only speculate on popular carburetor selection (why not a Rochester 4 Jet, why not a Stromberg 4A, why not a Carter WCFB, etc.), but my guess is most people today want a new carburetor instead of searching for a 60 to 70 year old core and rebuilding/tuning it themselves. Personally if I was going to go four barrel I would try the smaller bore Autolite 4100 carburetor, but there may be a good reason other people don't do that too.

[tubman]

The main problem is that all of the available 4-BBL manifolds have the old small "Square Base" mounting pattern. The means you have to run an adapter or use on of the older carburetors (early WCFB, early small base 4G, etc.) with the attendent availability and wear problems. There is someone who has posted on here or the H.A.M.B. that is running an early 4G with great success, but I forget who. I have 3 flathead 4-BBL manifold, an Edmunds, a Sharp, and a Fenton that I plan on using. I also have a small base 4G from a '53 Oldsmbile that I have rebuilt and am planning on using. It is for a 303 ci engine and my flathead is 258 ci, so I hope it's not off to much size-wise.

And "38 coupe" is right; those old carburetors are getting more and more difficult to find and those you do find are usually worn out and missing parts.

[Ol' Ron]

I have an Offy 4bl intake with the small carb intake. I installed and adapter for the modern 4bl carbs anf bores the intake to match the carb.
Gramps

[38convsedan]

41LJH: is this the offy intake you’re using?

[petehoovie]

Originally Posted by 38convsedan

41LJH: is this the offy intake you’re using?

[frnkeore]

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The thing about a Holley and the vacuum secondary's, is that the secondary's will not open, until there is enough air flow through the primary's to warrant it.

It is much like progressive linkage on 2 x 2 manifold and carbs but, it works on demand, instead of forced throttle position.

The 390 carb has 1 1/6 venturi and 1 7/16 throttle bores, similar to the late (2100) 94 type carbs.

In some bigger, high rpm engines, you could probably use the more common 450 cfm Holley, with 1 3/32 x 1 1/2 venturi / throttle. I have one of those, that was on a 327 Rambler.

There is a easy way to find out if your over carbureted and that is to hook up a vacuum gauge, that you can read in side the car and run it at full throttle to the max rpm you use, if the vacuum doesn't go under 1.5" vacuum your good for a street car, you can go as low as .5" for a race engine.

[aussie merc]

a couple that may have been overlooked is the good old carter AFB in 400 cfm[ they differ from the edelbrock which is a copy of the afb comp series so they run a bit richer ] or a WW from stromberg .Yeh its only a 2 barrel but still a good unit.

[olddaze32]

I have a Stromberg 4A Aeroquad that has my interest. Anyone out there had experience running them on a flathead?

[billy’s40]

Hello, Sir!

Do I need to put on a new intake manifold to use the Edelbrock carb? I just inherited my dad‘s 1940 Ford coupe. I’m just trying to make some changes to make it more reliable. I don’t need a new intake manifold, is there a certain adapter I need to use with the Edelbrock to make it fit on my flathead? Thank you.

[tubman]

If your main concern is reliability, your best bet is to have the proper stock original carburetor rebuilt by Charlie Schwedler in New York. There is none better.

If you're really looking for something else (optimal performance, gas mileage, or a "wowser" appearance), decide what it is and get back to us.

[Ol' Ron]

I just ran into a new old caeb. It,s a holley 485 from a chrysler 440 according to the list no. I haven't measured them yet, but the primaries are very small, and the secondaries are very bIG. Should make a nice street carb???
Gramps

[tubman]

Originally Posted by Ol' Ron

I just ran into a new old caeb. It,s a holley 485 from a chrysler 440 according to the list no. I haven't measured them yet, but the primaries are very small, and the secondaries are very bIG. Should make a nice street carb???
Gramps

Sorry Ron, probably not. A couple of years ago, I spent some time trying to get a quadrajet from a 3.8 GM V6 to run on a flathead. I had a Sharp 4 BBL manifold laying around, and I stacked a Quadrajet to Holley adapter on top of a Holley to Square pattern and did a bunch of filling and and blending to hopefully "smooth the airflow out". I had completely rebuilt the carb with a quality kit and to make a long story short, although I got it to start, run, and idle, the results were very disappointing. On the chance that I had screwed up the rebuild, I took the quadrajet off of a '68 Corvette 327 I had at the time that ran perfectly and mounted it on the Sharp with the same unsatisfactory results. (When I re-installed the carb back on the Corvette it ran perfectly again.) I posted a thread on the H.A.M.B at the time, and the general opinion was that I was just changing the flow characteristics way too much. Jon, ("CarbKing" over there) who is very knowledgeable about such things, said that anytime you use an adapter you mess up the airflow and using two such dissimilar adapters would lead to flow reversal, vortexes, and other undesirable effects. I abandoned the project, lesson learned.

So, to the O/P, the Edelbrock on an adapter would only cause problems. As said earlier, send your carb to Charlie Schwendler and have no worries. While you're at it, send the fuel pump, too. If you want to hear about what I consider the best "street" carburation for a flathead, rattle my cage and I'll expound on a small base 2G on a bored out late Merc manifold.

A couple of pics of my failed experiment.

[petehoovie]

Originally Posted by tubman

Sorry Ron, probably not. A couple of years ago, I spent some time trying to get a quadrajet from a 3.8 GM V6 to run on a flathead. I had a Sharp 4 BBL manifold laying around, and I stacked a Quadrajet to Holley adapter on top of a Holley to Square pattern and did a bunch of filling and and blending to hopefully "smooth the airflow out". I had completely rebuilt the carb with a quality kit and to make a long story short, although I got it to start, run, and idle, the results were very disappointing. On the chance that I had screwed up the rebuild, I took the quadrajet off of a '68 Corvette 327 I had at the time that ran perfectly and mounted it on the Sharp with the same unsatisfactory results. (When I re-installed the carb back on the Corvette it ran perfectly again.) I posted a thread on the H.A.M.B at the time, and the general opinion was that I was just changing the flow characteristics way too much. Jon, ("CarbKing" over there) who is very knowledgeable about such things, said that anytime you use an adapter you mess up the airflow and using two such dissimilar adapters would lead to flow reversal, vortexes, and other undesirable effects. I abandoned the project, lesson learned.

So, to the O/P, the Edelbrock on an adapter would only cause problems. As said earlier, send your carb to Charlie Schwendler and have no worries. While you're at it, send the fuel pump, too. If you want to hear about what I consider the best "street" carburation for a flathead, rattle my cage and I'll expound on a small base 2G on a bored out late Merc manifold.

A couple of pics of my failed experiment.

[TJ]

Originally Posted by billy’s40

Hello, Sir!

Do I need to put on a new intake manifold to use the Edelbrock carb? I just inherited my dad‘s 1940 Ford coupe. I’m just trying to make some changes to make it more reliable. I don’t need a new intake manifold, is there a certain adapter I need to use with the Edelbrock to make it fit on my flathead? Thank you.

Check with your local speed shop or on e-Bay. Those adapters are still available. I suspect they around $30 or so.

[Ggmac]

I’ve been using a Holley Economaster 4 barrel carb (450 cfm ) with great throttle response and no problems for over a year now . I like it so much I bought 3 more carbs to play with . They can be had for $40 and up on ebay . My manifold is edelbrock with an adapter . The cfm on these carbs varies according to applications, according to the Holley book .

[tubman]

Originally Posted by Ggmac

I’ve been using a Holley Economaster 4 barrel carb (450 cfm ) with great throttle response and no problems for over a year now . I like it so much I bought 3 more carbs to play with . They can be had for $40 and up on ebay . My manifold is edelbrock with an adapter . The cfm on these carbs varies according to applications, according to the Holley book .

Is this a "Spread-Bore" carburetor? If so, what did you use for an adapter? I have not been able to find a "Spread-Bore" to "Square" adapter anywhere.


In case the O/P ("billy's40") is not up to speed, a little information is in order. First, I believe that using a 4BBL to 2BBL adapter on a stock manifold just to mount a 4 BBL carb is a waste of time and money; there's just too much mismatching of airflow. Second, if you can find a 4BBL manifold for a flathead, it will have the old "Square" mounting pattern. The only carburetor that will bolt directly to these manifolds will be an early Buick Stromberg Aeroquad, an early Carter WCFB, or and early ('52 or '53) Olds or Caddy Rochester 4G. Anything else will need an adapter. Adapters for "Square Bore" Holley's and Carter AFB's (Edelbrock's are the same) are available but surprisingly getting harder to find. I've had a Holley 390 on and Offenhauser manifold (with adapter) and it ran fine. (Please note that "Square" and "Square Bore" are two different mounting patterns.)

In my opinion, the best approach for using a 4 BBL on a flathead is to use one of the "Square" carbs on an aftermarket manifolds. On a practical basis, the Aeroquads are out because they are scarce as hen's teeth with parts are even worse. A lot of the WCFB's have been priced into the stratosphere by the Corvette guys and early Mopar muscle folks. This leaves the Rochester. Although I've never run one on a flathead, many here have and speak quite highly of the combination. Charlie Schwendler has contacted me and informed me that he still has rebuildable cores and affirms that they are a perfect fit for a flathead.

[Ggmac]

It fits a spreadbore bolt pattern but the venturies are aprx the same diameter. I just used a spreadbore to holley adapter on one and redrilled the offey adapter plate on the other . Or I redrilled the carb base , can’t remember now .
They aren’t performance carbs and they come in many jetting and apparently cfm ratings , from v6 buicks to big block Chevys .

[flatjack9]

Originally Posted by petehoovie

When using an open adapter like that, you generally need to up the main jets 3 to 4 sizes.

[tubman]

Originally Posted by flatjack9

When using an open adapter like that, you generally need to up the main jets 3 to 4 sizes.

I temporarily shelved this project, mainly because of the lack on initial success and the fact that I realized I was out of my depth for a project like this. Your information will be useful should I ever decide to revive it. One of my rules was this project was that I did not want to modify the Sharp manifold in any way. From some of the posts here, it seems that this can be made to work, although I have strong suspicions that that the carbs are functioning as 2BBL's only. In all actuality, I probably won't get back to this because of the success I have experienced with Rochester 2G's on Merc manifolds.

[deuce_roadster]

I don't care for Quadra jets on anything and can't imagine one would work well on a flathead. I have a small 390 Holley on my 40 coupe and a friend who tunes all the race cars in the area made it run perfect. He changed the jets modified air bleeds, can't remember if he changed the metering blocks. I have the carb on the Offy intake with an adapter to raise it up higher and backwards, so the throttle linkage is easy to deal with.

[Ol' Ron]

YES!! Thats the intake I'm using.
G