Aftermarket Carb Question

[raynman]

Hello all,

First post as an aspiring M37 gear head- just towed home my '53 home yesterday. Dad has had a '52 since I was a teenager, so I think it must be in the blood.

Issue is the carb on my M37 is rubbish and the previous owner said that it needed to be rebuilt. Truck barely runs. I have searched this forum and the rest of the web and am having some challenge finding the answer to my question, which is are there aftermarket carbs out there that I can/should swap to?

Looking around, I think I saw an Offenhauser manifold that would work on a 230 Six and it sports dual singles (Edelbrock or Speedway version Strombergs). Is this a bad idea? Would I gain any more streetable behavior and better tuning?

 

[WarrenD]

I think a properly functioning stock carb is just fine. The biggest problem is the ethanol in the gas, it rots the rubber parts in no time. Modern rebuild kits, like the ones available from Then and Now Automotive have rubber parts that are more resistant to the ravages of ethanol.
If you want to retain the stock look, this is the way to go. You're not going to get more HP out of that 230 and dual carb set-ups can be a nightmare to keep tuned.

 

[raynman]

Add on question, I have the fording carb (or whatever you call it for a sealed air filter) is there any merit in going with a non-fording carb or at least a normal open-element air filter? I am coming from a point of complete ignorance, but I would have to imagine the fording set-up is a bit restrictive.

 

[WarrenD]

Post a pic of what you have. Much easier to tell, picture worth a thousand words!

 

[scoutmanadam]

Pics would be great as there are many, many diffrant carbs out there. also, welcome to the site from another guy from Washington, and not far from you to boot.

 

[raynman]

First two are shots under the hood, but the sun is going down and the glare is pretty bad. I will take another stab at it tomorrow. The last one is just because.

Untitled | Flickr - Photo Sharing!

Untitled | Flickr - Photo Sharing!

Untitled | Flickr - Photo Sharing!

 

[Squirt-Truck]

You do not have the fording air cleaner, yours is the open one, so no restriction there.
The OEM carb is just fine, just rebuild it or have it rebuilt.

 

[WarrenD]

Yep, that's the oil bath air cleaner, you are all set. It's not recommended to run the fording kit if you don't need it. Too much restriction on intake and exhaust.

 

[mobilized medic]

Yo Rayneman;
Great looking first MV! I am "green" with envy.
I have 2 M43s with all original carbs,etc.
Get the carb manual and a modern rebuild kit. You will be amazed at the enhanced performance.
In my opinion, for the dinking around trying to change over to a civvie carb/manifold,
time/money better spent becoming "acquainted" with the military fuel system.
Besides the carb, make certain lines are free of debris and the fuel filter working and the gas tank not "shedding" corrosion into fuel lines. You may be surprised to find the solution to your situation is not just in fixing the carb.
You have to give credence to the longevity of the original system for enduring the years of neglect/abuse/corrosive fuels. These trucks are pretty easy to fix and reliable even when not running their best.
In truck karma, they are very "forgiving".
The cab kit I got from Midwest Military was inclusive of printouts , but I also relied on the carb manual. Others more expert than me can point out different kits,etc.
Took one day to rebuild with simple tools.
Good luck, welcome to the "M-pool" and NO, there is no cure for this affliction.
Kinda like "taking the oath" Soldier.
Mobilized (and one with my truck) Medic

 

[plym49]

Hello all,

First post as an aspiring M37 gear head- just towed home my '53 home yesterday. Dad has had a '52 since I was a teenager, so I think it must be in the blood.

Issue is the carb on my M37 is rubbish and the previous owner said that it needed to be rebuilt. Truck barely runs. I have searched this forum and the rest of the web and am having some challenge finding the answer to my question, which is are there aftermarket carbs out there that I can/should swap to?

Oh, BTW, those Speedway Stromberg clones have a terrible reputation. Stay away.

Looking around, I think I saw an Offenhauser manifold that would work on a 230 Six and it sports dual singles (Edelbrock or Speedway version Strombergs). Is this a bad idea? Would I gain any more streetable behavior and better tuning?

I have one of those manifolds on an OT vehicle and I can tell you that they are not for a MV. Folks who use them are either posers or those seriously interested in getting as much power as they can out of that little engine. Neither scenario maps to the type of use you see in an M37.

There is no reason you cannot rebuild that carb, or send it out to a good rebuilder. It will need to be dipped in a professional-grade carb cleaner, and at worst the throttle shaft holes in the base might need to be drilled out and bushed.

Other than that these carbs are simple and elegant.

I am always amazed that the kneejerk reaction to a carburetor problem is usually to 'install an aftermarket carb'. Why should it be easier to install and dial in something custom, as opposed to that which has been proven to work well in hundreds of thousands of vehicles for millions of miles? No offense meant, that is not a shot at you, it is an observation I see all the time (and I am not sure why).

Oh, BTW, those Speedway Stromberg clones have a terrible reputation. Stay away.

 

[JasonS]

I am always amazed that the kneejerk reaction to a carburetor problem is usually to 'install an aftermarket carb'. Why should it be easier to install and dial in something custom, as opposed to that which has been proven to work well in hundreds of thousands of vehicles for millions of miles? No offense meant, that is not a shot at you, it is an observation I see all the time (and I am not sure why).
away.

In short, they work better. We installed one of Stovebolt's carbs on my brother's M37:better driveability and starts. I put a newer Holley 2300 economaster on my M35; significantly better performance. You have to give credit to the fact that carbs did get better with time.

 

[mobilized medic]

Yo Raynman;
Told ya. Lots of great info to start with. I like to listen up , pull out the manuals, fire up and then roll up the shirt sleeves. Then usually back to listening.
Gotta love those "engineers". Lots of great stuff has rolled out of home garages,out from under the old oaks in back yard, and from crowded alleyways. Sitting in a lab or with a CAD is not always the answer.
Also points out ,that even though all these vehicles were supposed to be uniformly managed ad maintained, why so many of them have been "altered" to meet the demands of the units they served with. Including the "home fronts".
Regards,Mobilized (and with an ear to the ground) Medic

 

[saddamsnightmare]

September 7th, 2012.

If it were me, I'd rebuild the original carburettor or replace with same if it were beyond repair, but I would get a new silicone rubber rebuild kit as you are about to enter the **** of ethanol. Unimog's that are much newer hate ethanol, so I suppose Chryslers from the fifties really hate the stuff.

Most modern mechanics neither understand nor can properly care for a carburettor, as they have been trained on computerized trouble shooting and almost none of them can competantly repair a pre computer era car or truck beyond basic mechanics of the engine, eg, rebuilds and major repairs, because the old technology is "foreign" to them.

The M37 had its good pints, and so my advice is restore, not abjure what is there.

 

[raynman]

Good points, thanks all. I guess my "knee-jerk" response stemmed from my days with an ailing quadrojet on my '69 Camaro that I replaced with a Carter AFB and never looked back

 

[plym49]

In short, they work better. We installed one of Stovebolt's carbs on my brother's M37:better driveability and starts. I put a newer Holley 2300 economaster on my M35; significantly better performance. You have to give credit to the fact that carbs did get better with time.

Excuse me, captain, but that is illogical.

All your experience indicates is that the replacement carb you installed was in better shape than the stock one you removed.

It does not mean that a properly operating stock carb is not perfectly fine.

Spock out.

 

[mobilized medic]

Yo General McGrogan;
Abjure..ABJURE!!??
Bad enough that I am scambling through the manuals for these technical terms thrown around this forum, now I have to play catch-up vocabulary? My Funkin Wagnall's so thumb worn you can see through the pages.
Abjure.
Wait until I walk through the ER tomorrow and throw that one around. Supervisor will think I am abusing the staff. Next stint, Kosovo.
Good stuff this forum. Think I will abjure that tech manual and wing it on next brake job.
Mobilized(and at a loss for words) Medic

 

[plym49]

Yo General McGrogan;
Abjure..ABJURE!!??
Bad enough that I am scambling through the manuals for these technical terms thrown around this forum, now I have to play catch-up vocabulary? My Funkin Wagnall's so thumb worn you can see through the pages.
Abjure.
Wait until I walk through the ER tomorrow and throw that one around. Supervisor will think I am abusing the staff. Next stint, Kosovo.
Good stuff this forum. Think I will abjure that tech manual and wing it on next brake job.
Mobilized(and at a loss for words) Medic

Fascinating.

 

[JGBallew]

Good points, thanks all. I guess my "knee-jerk" response stemmed from my days with an ailing quadrojet on my '69 Camaro that I replaced with a Carter AFB and never looked back

In defense of the Quadrajet-

Depends on how you drive. A properly set up Q-Jet is a fantastic mileage carb, as long as you keep your foot out of the secondaries.
But if you don't have access to the metering orifices and needles, and you know how to set one up, you'll have driveability issues (unless you found a Q-jet meant for your application, i/e displacement and trans).

 

[JasonS]

Excuse me, captain, but that is illogical.

All your experience indicates is that the replacement carb you installed was in better shape than the stock one you removed.

It does not mean that a properly operating stock carb is not perfectly fine.

Spock out.

Maybe perfectly fine for you...

If stuck with a carb, I want the best one I can get.

Even if I were to rebuilt the original, there are DESIGN differences that you are not considering. For example, the economaster carbs have a number of improvements developed in search of better fuel economy:
1) Reverse idle system which improves idle quality
2) Two stage power valves which improve driveability in vehicles with relatively low power to weight ratios (should also improve fuel economy since you are not providing an unnecessarily rich ratio)
3) Wagonwheel boosters for a stronger signal to the main circuit and better mixing so you don't have to supply an unnecessarily rich ratio

Fuel economy gains for this carb over the prior 2300s (already good carburetors) were 5.8% city and 6.5% hiway.

I did a pretty exhaustive search to find the best 2bbl that I could get. The Webers were too much money and TBI would have required a switch to 12 volts. I found very positive reviews online about the excellent driveability of the economaster carb and was able to validate it myself. I also found that it also was able to tolerate a hot soak much better.

 

[plym49]

Maybe perfectly fine for you...

If stuck with a carb, I want the best one I can get.

Even if I were to rebuilt the original, there are DESIGN differences that you are not considering. For example, the economaster carbs have a number of improvements developed in search of better fuel economy:
1) Reverse idle system which improves idle quality
2) Two stage power valves which improve driveability in vehicles with relatively low power to weight ratios (should also improve fuel economy since you are not providing an unnecessarily rich ratio)
3) Wagonwheel boosters for a stronger signal to the main circuit and better mixing so you don't have to supply an unnecessarily rich ratio

Fuel economy gains for this carb over the prior 2300s (already good carburetors) were 5.8% city and 6.5% hiway.

I did a pretty exhaustive search to find the best 2bbl that I could get. The Webers were too much money and TBI would have required a switch to 12 volts. I found very positive reviews online about the excellent driveability of the economaster carb and was able to validate it myself. I also found that it also was able to tolerate a hot soak much better.

That is excellent information but I submit that the example is apples and oranges.

Can more advanced carbs exist? You bet. Why stop there, are there even better alternatives available? Yes again, all sorts of EFI alternatives are available, some more advanced than others.

But unless I am mistaken, this thread was about a whether the stock carb can work correctly, or if it had to be replaced because the stock carbs were, in the vernacular, crap.

That is different than a discussion of how far you can modify something.

I maintain that a properly rebuilt stock carb can work just fine.

If the intent is to modify the engine to achieve a particular goal, then all bets are off.