Trying to put a two barrel, primary with secondary in place of my one barrel carb.

[Bern Pearson]

I have a 1948 Plymouth Special Deluxe with the 219 CU single barrel carb.  The car is stock except for a 12V conversion.

 

I fell in with bad company and they've talked me into switching the single barrel carb for a dual primary with secondary.  But since these are V8 guys they couldn't tell me which carb might do a good job.  We calculated anything from about 175CFM to 200CFM.

 

Has anyone done this?  If so:

What carburetor did you use?

What adapter plate?

Did it improve drivability?

 

Bolt to bolt on the carb to manifold measures 2 7/8.

 

Thanks.

Bern 

[maok]

Go straight to the Weber 38/38 skip 32/38, you will need the carb adapter, Tom Langdon sells one fairly cheaply.

[Loren]

My first choice was also Plymouth & Dodge’s first choice. The Bendix Stromberg model WW. They were used on the power pack option. These carburetors are super easy to work with and can be found nos for a reasonable price. I bought one new with the Overdrive switch bracket for $150.

they will also fit an adapter so you don’t have to change the manifold.

Linkage has to be fabricated or find a 1955-56 power pack donor car.

[Los_Control]

First thing to clarify is your goals for the engine/car.

 

The typical carter Carburetor worked for these engines All the way from the 30's to the 70's on Flathead 6 engines.

I understand if you want to go custom headers, more cfm from the carburetor .... I do not think that is what you are after.

For my truck I was able to purchase a rebuilt carburetor from Rock Auto ... There are many shops that can rebuild your existing carburetor. 

Is actually pretty easy if you want to watch a video from Mike's Carburetors & purchase the rebuild kit .....

Now if the body is worn, it needs to be drilled and a new oversize bushing installed so the shafts do not leak air out of the side of the carburetor, people still do this if you can find the right shop.

 

Just saying your 1 bbl Carter Carb was used from the factory for 50 years with no issues on your 95 horsepower engine. Just fixit.

If your goal really is to increase horse power on your stock flat 6 engine ....not sure the carb would be the best place to start.

[plymouthcranbrook]

I have the Langdon set up on my stock 52 Cranbrook and am very pleased with it.  Not horribly expensive and although takes a little work, the results are worth it to me.

[Los_Control]

1 hour ago, Bern Pearson said:

I have a 1948 Plymouth Special Deluxe with the 219 CU single barrel carb.  The car is stock except for a 12V conversion.

 

I fell in with bad company and they've talked me into switching the single barrel carb for a dual primary with secondary.  But since these are V8 guys they couldn't tell me which carb might do a good job.  We calculated anything from about 175CFM to 200CFM.

 

 

I fell in with bad company and they've talked me into switching the single barrel carb for a dual primary with secondary. 

 

This is the sentence I'm reading ..... I'm just not feeling the completely stock mopar with a 12 volt conversion .... Is exactly what the owner wants.

 

I really would like to hear more from the owner to describe what they do want.

As it sits I Am thinking the owner needs to get as far away as fast as they can from their current mechanic.

 

I have no issues with Langdon, I personally would lean to a Webber 2 bbl single carb for performance ..... Thats not the question I'm seeing from the original poster.

[Los_Control]

While the mechanics may be fine .... 95 Horse flathed Brigs & Stratton  Lawn mower engines really is not their cup of tea.

They may build awesome sbc or LS motors.

 

The flatheads are known for not breathing well.

So adding more cfm to a carburetor that the engine can not handle efficiently .... yes that looks pretty cool .... does it actually help? Or hurt?

 

Just asking Are we helping a stock running car, or are we hurting the stock car?

 

[Sniper]

7 minutes ago, Los_Control said:

The flatheads are known for not breathing well.

 

Turbo time

[Los_Control]

My goal is to cruise on the highway.  As it is the car is tapped out around fifty-five miles per hour.  (As I said, I've fallen in with bad company so this might not be the way to go.)  I didn't want to mess with the rear end, which is probably five or six to one.  Or, the transmission which seems to work well.  No, I don't want headers.  I was hoping to use the oil bath air cleaner as I love the look of the stock engine. 

 

Those are the goals.  Did you have further thoughts on how to achieve those?  

 

 

Just sharing a post to pm that I think the op meant to share here

 

[Los_Control]

So obvious issues .... carburetor is not one of them

 

[desoto1939]

ok, so you want to run the v-8 cars but you have a 6 cylinder car.  The question that I have is when you are with these guys at what highway speeds are they driving/ What year cars/trucks are they driving, what brake modifications and rear end modifications have they made to their cars/trucks.

 

These are questions that should be answered.  I have a 39 Desoto with the 25 inch block with the original stock carter carb E6N1 model.  I just drove my 39 from Philadelphia pa to Altoona and back and averaged 15-17 MPG.  This was all done via the PA turnpike and running around 50-53 MPH.  I had no issues with trucks and or other car drivers. They cave me plenty of room and alot of people acknowledged the car as they went around me.

 

My other friend was driving his 39 Desoto at 60 MPH so when he stopped for gas I was approx 5 minutes behind him. The time difference did not matter to me.  My cars sweet spot is the 50-53 MPH mark.  I did not want to be going 60-65 in an almost 85 year old car with the original braking system.

 

So if you want to keep up with you friend then get a more modern car that is an antique. Enjoy the time and pleasure that we have wit these older nostalgic vehicles. So basically you are pedaling a tricycle but want it to be racing bike that is used in the Tour Defrance.

 

Rich Hartung

desoto1939@aol.com

[kencombs]

Being a non-conformist by nature, my plan is a small two barrel originally used on 273-318 engines by ma mopar.   But, doing it my way is a major mod.   If I just wanted better performance, and potentially better fuel mileage then my choice would be the Langdons kit, or a home brew version thereof.  Those little progressive two barrels have been used successfully by millions of cars/small trucks since the 60s/70s.  Ford, Nissan and a horde of others.  Simple, reliable and very tuneable for specific use.

Edited July 2, 2022 by kencombs

[Bryan]

Change the tire size?  https://www.jeepfan.com/tech/tire-to-rpm-ratio-chart/#:~:text=If you’d like to know your speed at,diameter to the linear distance the tire travels.  

 

 

[greg g]

Carburetor change will have zero effect on mph per rpm at cruising speed.  Long stroke and high numerical rear end gears are your factors here.  Rpm at 60 mph will be around 3200 to 3400 depending on gear and tire diameter.  No carburetor change will change the math involved in that equation. 

 

[FarmerJon]

On 7/2/2022 at 2:04 PM, Bern Pearson said:

My goal is to cruise on the highway.  As it is the car is tapped out around fifty-five miles per hour.  (As I said, I've fallen in with bad company so this might not be the way to go.)  I didn't want to mess with the rear end, which is probably five or six to one.  Or, the transmission which seems to work well.  No, I don't want headers.  I was hoping to use the oil bath air cleaner as I love the look of the stock engine. 

 

Those are the goals.  Did you have further thoughts on how to achieve those?  

 

I have the same car, a mostly stock '48 Special Deluxe. My only performance modification is a dual exhaust and a good tune up. No headers, just a split factory manifold. 

Stock Rear end ratio is 3.9-1. Someone could have swapped a 4.1 center in, but even if so, car is mechanically capable of 70+mph

Is your car unable to exceed 55mph, or are you unwilling to drive faster than 55mph?

I have run up to 75 or so, but it handles much nicer at 65. 

If you have the pedal to the floor at 55 and it won't go any faster, then you need to find the problem and fix it. 

 

Only real way to alter cruising RPM at a given speed is to alter your final drive ratio. You could change rear gear ratios, there are 3.73 and 3.54 ratios that can be found for your existing axle. You could put a taller tire on the rear. Or you can swap some sort of overdrive transmission in. '52-56 a Overdrive was offered as an option, it is a direct bolt in to your car. Many people here have installed the more modern T5 transmission.

 

As far as performance out of the flathead six, there are gains to be had.

 

 

 

Edited July 4, 2022 by FarmerJon

[Los_Control]

Just now, FarmerJon said:

Just sharing a post to pm that I think the op meant to share here

It really was a post I shared that the op meant to post here.

The original poster really did not understand the posting sequence & sent me a pm instead of replying to the original thread here.

 

I dunno what proper procedure is, I just did not feel qualified to answer all their questions in private so I copy/pasted the private reply here.

Thinking the poster would get more replies/help here in public forum then a private forum.

 

For whatever reasons, we have not seen the original poster back.

 

[FarmerJon]

Tracking, corrected quote to reflect OP.

[tom'sB2B]

I have a Langdon's 32/36 Weber on a rebuilt 230 1947 Dodge. Original fluid drive trans. Original rear end. Electric fuel pump.

I'm very happy with it. I can cruise comfortably at 65, but rarely need to.

Is it necessary for better performance?..not really

Do you get better gas mileage?.. probably.

For the price of finding a single barrel Carter BB that's not worn out might be comparable to the price of a new Weber.

I'm not knowledgeable to argue the merits of double vs single.

My car starts reliably. It idles smoothly. I don't need it warm up to drive.

My 2 cents

This may or may not help

 

 

 

 

[James_Douglas]

On 7/4/2022 at 5:31 PM, tom'sB2B said:

I have a Langdon's 32/36 Weber on a rebuilt 230 1947 Dodge. Original fluid drive trans. Original rear end. Electric fuel pump.

I'm very happy with it. I can cruise comfortably at 65, but rarely need to.

Is it necessary for better performance?..not really

Do you get better gas mileage?.. probably.

For the price of finding a single barrel Carter BB that's not worn out might be comparable to the price of a new Weber.

I'm not knowledgeable to argue the merits of double vs single.

My car starts reliably. It idles smoothly. I don't need it warm up to drive.

My 2 cents

This may or may not help

 

 

 

 

Tom, Is your car a three speed or an M6? I am assuming a 3 speeds as the weber would not work with the carb wiring with the M6...

 

James

[tom'sB2B]

32 minutes ago, James_Douglas said:

Tom, Is your car a three speed or an M6? I am assuming a 3 speeds as the weber would not work with the carb wiring with the M6...

 

James

It's a 3 speed with fluid drive.