Model B carb on a Model A

[denniskliesen]

I can make it fit. Is there an advantage or disadvantage to a Model B carburetor. Anybody done it here?
Thanks for anybody's advice.
Dennis

[Charlie Stephens]

One of the tricks to make it fit, which you may have already discovered, is the bolts that the vendors sell that are cut to allow the carburetor to be rotated sightly to make it line up. It is a larger diameter and should give a couple of extra horsepower but you need to hog out the Model A intake manifold of run a Model B manifold to get the benefit.

Charlie Stephens

[TinCup]

With the float bowl mounted sideways it is not a susceptible to stalling at sudden stops. Yes with a bored intake it can give you 10% boost in HP.

[Ernie Vitucci]

Good Morning...I have been running a B Carburetor with a B intake for about 12 years on an early 1931 Tudor. I love it and it does give a bit more power. If you can get one, run it. You can drill out the A intake if you have to or easier yet, take the A intake to a machine shop and let them drill it out for you. Ernie

[denniskliesen]

Originally Posted by TinCup

With the float bowl mounted sideways it is not a susceptible to stalling at sudden stops. Yes with a bored intake it can give you 10% boost in HP.

10% ?!?! That's quite a bit for just a carb and manifold bore.

[Terry, NJ]

Sponsored Links (Register now to hide all advertisements)

I have run an B Carb on an A manifold with no modification to the Carb or bolts. I think that you need to do the Mods if you're going to use an B manifold. I would use an A manifold , but port and polish it first. That means getting some long grind stones with an arbor to put in your 1/4 (?) drill. I would first drill the carb runner out to between 1 1/4 (1.250) and 1.300and polish it. Next I grind the mouth of the other two runners to match the gasket (Size and location) and then clean up the runners as best I can. This will give you about 3-4 HP 10% 0f 40 HP=4 HP . Check Pirianos site on Mod A HP. If you leave the A manifold the stock, unpolished 1 ". you will get very little increase. And if you port and polish the A manifold and use the A carb you will notice a slight improvement. Be careful with a B carb as the mounting ear on the rear break easily. A parts don't fit a B carb but B parts are available from the vendors. As has been said, The B float is mounted crosswise and the B carb is not so prone to stalls with sudden stops. Good Luck!
Terry

[denniskliesen]

Is a B carburetor balanced so you can use a air filter on it? Or does that need to be modified.

Terry, so you open the carb itself up above the throttle plate? Doesn't sound too hard to open the intake and carb. I have a boring tool I can chuck up on my lathe to open the manifold. dingle berry hones etc.

[Dave in MN]

"Terry, so you open the carb itself up above the throttle plate? Doesn't sound too hard to open the intake and carb. I have a boring tool I can chuck up on my lathe to open the manifold. dingle berry hones etc."

No Dennis, I think Terry means to open up the primary carb runner of the intake manifold...not the carb.

I have a visual explanation of the process on my website.

On my website, go to the DIY Help page and open up the Intake Manifold Enlargement article.

my website: www.durableperformance.net

Good Day!

[Terry, NJ]

No, no! No modification to the carb itself, only the manifold. Do you have a Bridgeport? If so, bore the primary runner out to 1.250-60 +, then polish to 1.280 +. Just keep it under 1.300, the walls are getting thin! Then align the ports with the gasket (1 piece) and clean them up. These manifolds are still rough castings inside, lots of obstructions to good flow.
If you can keep the engine clean (But only if, don't try it if the grit is going to get in the engine ) Round out the ports in the block and match the gasket. Again, Don't try it if you can't be sure of keeping all the grit out of the engine.
I'm afraid there isn't much work for a lathe, only a Bridgeport!
Terry

Originally Posted by denniskliesen

Is a B carburetor balanced so you can use a air filter on it? Or does that need to be modified.

Terry, so you open the carb itself up above the throttle plate? Doesn't sound too hard to open the intake and carb. I have a boring tool I can chuck up on my lathe to open the manifold. dingle berry hones etc.

[Terry, NJ]

Dennis, I ignored the first part about the air filter. So to correct that I'm going to say I have not seen any air mazes that are for a B carb, only A bores. Chances are that they make them, it's just that none have come my way yet. If your lathe has enough swing, you could make a fixture out of a faceplate and an angle plate to hold them and bore them deep enough to get them on your B carb. Set up would take some time but once that was done the actual cutting would go quickly. Also, you may find a B carb with a broken ear and be able to save it by making a base plate from steel and brazing it on to the base.
Terry

Originally Posted by denniskliesen

Is a B carburetor balanced so you can use a air filter on it? Or does that need to be modified.

Terry, so you open the carb itself up above the throttle plate? Doesn't sound too hard to open the intake and carb. I have a boring tool I can chuck up on my lathe to open the manifold. dingle berry hones etc.

[denniskliesen]

Terry, and everybody else, thanks for all the information. I noticed on Vince's site there a couple (?) air filter/sound reducers. One of his samples had a screen in the bottom.

[denniskliesen]

Just thought of something. Model B had a fuel pump, I have an electric pump with a filter ahead of it but not sure of the relief pressure and would have to get a regulator I'm sure. What should the running pressure be set at?

[d.]

I've got a B carb bolted to my 1929 A intake...no boring out anything, just bolted on...works great, no problemas. I'm not looking for hp gain, it's just the way it came to me.

[Terry, NJ]

D. Get the A manifold bored out to B specs and it will run even better. You're processing more air through that larger throat and then choking it down.
Terry

Originally Posted by d.

I've got a B carb bolted to my 1929 A intake...no boring out anything, just bolted on...works great, no problemas. I'm not looking for hp gain, it's just the way it came to me.

[Terry, NJ]

No it works fine on a gravity feed. But I almost forgot, You'll need different plumbing on the fuel lines. Either a couple brass fittings or a custom line, made and sold by B&B a parts, here in Pa. I think he gets maybe $15 for one. I grabbed one from him, it has all the right bends for a B carb. Check the vendors, Like Brattons. I don't think B&B is too well known outside the state.

Originally Posted by denniskliesen

Just thought of something. Model B had a fuel pump, I have an electric pump with a filter ahead of it but not sure of the relief pressure and would have to get a regulator I'm sure. What should the running pressure be set at?

[denniskliesen]

Originally Posted by Terry, NJ

No it works fine on a gravity feed. But I almost forgot, You'll need different plumbing on the fuel lines. Either a couple brass fittings or a custom line, made and sold by B&B a parts, here in Pa. I think he gets maybe $15 for one. I grabbed one from him, it has all the right bends for a B carb. Check the vendors, Like Brattons. I don't think B&B is too well known outside the state.

Are they tapered pipe thread? I have a local hardware store that has a good selection.I'll have to check out B&B. Got a link?

[Jay C Bolton]

Fords came with air cleaners starting in 32,including the B. And no, it was not air balanced

[Terry, NJ]

No they're a straight machine thread, !/2 X 20 or 7/16 X 20 (Can't recall) The one Bill Savitz Makes and sells is perfect, Mine still has the tag on it $9.75! The name is B&B Mod A Ford Parts, 8752 Breinig run circle, Breinigsville, Pa.
Bill used to run B&B from Phillipsburg Nj, but he's getting old and gave up a lot of it. He still sells Carbs and distributors and small stuff and these fuel lines. The only one I know of who makes them. I can't recall seeing them anywhere else. I don't have a Phone number yet, but when I find his card, I'll forward it onto you. 610-928-0988 Don't tell him I gave you the number. He doesn't know me, I just bought a few things from him and remembered him. I had his card, but can't find it now. Good Luck!
Terry

Originally Posted by denniskliesen

Are they tapered pipe thread? I have a local hardware store that has a good selection.I'll have to check out B&B. Got a link?

[Chuck Sea/Tac]

If you're running pressured fuel then leave B carb stock. If gravity, the remove the baffle . As I recall? I've been using a B for years. Also, as mentioned, like the late 31, the ears a thin, so tighten in increments. Especially,if like me you put a insulating spacer between carb and manifold to help with heat vapor.

[denniskliesen]

Originally Posted by Chuck Sea/Tac

If you're running pressured fuel then leave B carb stock. If gravity, the remove the baffle . As I recall? I've been using a B for years. Also, as mentioned, like the late 31, the ears a thin, so tighten in increments. Especially,if like me you put a insulating spacer between carb and manifold to help with heat vapor.

Chuck, is one of those 1/4" thick spacers adequate?

[Terry, NJ]

Dennis, Go to my profile and open the album, Miscellanius (sp) There are three side by side pictures of an A and a B carburetors. I tried to post a picture of the fuel line in a carburetor. but it will not post, It's imported, but I can't post it. Go figure! G--D---ned computers! So good luck with your project!
Terry

[Tom Wesenberg]

Terry, if your pictures are trying to be imported from Photo bucket, those crooks are blackmailing everyone to pay $400 a year to see the pictures.
Sure glad I dropped them about 5 years ago.

[denniskliesen]

I never did pay them. It was just easier to use them for some sites that didn't have room for a bunch of pictures. Dealing with the adds on their site was a pain in the butt anyway, don't miss them.

[denniskliesen]

Thanks Terry BTW.

[Terry, NJ]

No it isn't Photobucket. Fortunately, I tried to get into PB a few years ago, but it was too confusing. (I just don't "get" computers) How about Picasa? I was told about Picasa years ago and I used it and never had any trouble with it. But I've got a Mac now and it's a little different.
Terry

Originally Posted by Tom Wesenberg

Terry, if your pictures are trying to be imported from Photo bucket, those crooks are blackmailing everyone to pay $400 a year to see the pictures.
Sure glad I dropped them about 5 years ago.

[mngreen]

Sponsored Links (Register now to hide all advertisements)

Dennis, so I guess you don't like your Weber carb?

[denniskliesen]

Mike you're giving me away... What I didn't like about it was the acceleration off idle. Is it the nature of a Weber? I don't know. I will say this when you step all the way down, she's got power But I don't need power driving around on our streets. It just didn't feel right coming off a stop light. The Tilly is so much smoother leaving a traffic light but she can stumble and lose power on a curving mountain road. Float level is set correct, I have one of those external hose with the wire inside things, so I know that's ok. Another thing I'm sure could have been corrected with the Tilly is it acts like it boiled the gas out of the bowl if it's shut off for 15 - 30 minutes and I try to start it up. I can get it started but I have to open the throttle to keep it running. I noticed this as the ambient temperature raised this year. It would clear itself up after 30 seconds after it was started. Maybe a phenolic spacer would have fixed this. The Weber I never completely went through it so it may have been fiddled with before I got it and I'll take the time to do that later. It needed an accelerator pump diaphragm right off the bat and I fixed that but the poor acceleration from a stop was annoying. I picked up a B carburetor cheap and decided to give it a try. I've read and been told more positive remarks about a B carb.

[denniskliesen]

Finally getting ready to mount the B carb to my Model A. Need some help with the orientation of the throttle plate. Mine has a notch on the plate on one side, factory not modified. In the illustrations the plate number is 9585. So which side does the notch go towards?

[Terry, NJ]

Look at the small angles on the edge of the plate and orient the plate to the angles. One way it go, the other way it will not go.
Terry

Originally Posted by denniskliesen

Finally getting ready to mount the B carb to my Model A. Need some help with the orientation of the throttle plate. Mine has a notch on the plate on one side, factory not modified. In the illustrations the plate number is 9585. So which side does the notch go towards?

[denniskliesen]

Terry, I figured it out early this morning. My upper carb body is the mid production looking at Vince's site on B carbs, has a brass insert instead of the drilled hole in the casting. The plate is for a early production. I just flipped it over so the notch is on the opposite side of the bore from the idle orifice. The picture is just to show where the notch is, I didn't leave it that way.

[john charlton]

Ford built AA Trucks in England into 1936 . These were factory fitted with model B engines and carbs . At first the A inlet manifold was retained as the RHD manifold has a peg on it for the advance/ retard linkage pivot . These inlet manifolds were not bored out to suit the larger bore B carb so there was a 1/16" step in the inlet tract which Ford seemed quite happy about . Later production the advance/retard lever was deleted on the steering column and the B distributor fitted . I think that it would only make a difference at very wide throttle openings as the throttle plate is a much bigger obstruction to flow than the manifold/carb mismatch .I have a car with a B carb on an A manifold and it runs like a champ . Just wondered what a dyno test would show at normal throttle openings I cant think there would be much difference IMHO !!! I do have an English B carb (different markings on it) I ought to check to see if the mounting flange is aligned for the GAV driver .

John in sunny Suffolk County England .

[Fred K-OR]

For what it is worth at this point, I had a B carb on my huckster. I did not have the manifold bored out so did not get the full benefit of it. So I took it off and put an A carb back on because I noticed I did not get very good mileage using the B carb. Also when I had it on the rig, I ordered a filter from a vendor and found it would not fit the B carb. Anyway for what it is worth!

[Terry, NJ]

John, Try " Pirianos Mod. A s " site. They ran a Mod.A engine in all states of modification, with and without B carbs.
Terry

Originally Posted by john charlton

Ford built AA Trucks in England into 1936 . These were factory fitted with model B engines and carbs . At first the A inlet manifold was retained as the RHD manifold has a peg on it for the advance/ retard linkage pivot . These inlet manifolds were not bored out to suit the larger bore B carb so there was a 1/16" step in the inlet tract which Ford seemed quite happy about . Later production the advance/retard lever was deleted on the steering column and the B distributor fitted . I think that it would only make a difference at very wide throttle openings as the throttle plate is a much bigger obstruction to flow than the manifold/carb mismatch .I have a car with a B carb on an A manifold and it runs like a champ . Just wondered what a dyno test would show at normal throttle openings I cant think there would be much difference IMHO !!! I do have an English B carb (different markings on it) I ought to check to see if the mounting flange is aligned for the GAV driver .

John in sunny Suffolk County England .

[denniskliesen]

Follow-up on the results with the B carb. I went ahead with the B manifold beings I had it plus it just seemed easier for me to do a minor modification to the carburetor mounting flange. I built up a couple of the sides of the flange to get a positive full gasket surface when I moved the holes to get the correct angle so my GAV rod was straight. All of the surfaces including both manifolds and carburetor were honed to match to eliminate any leaks. For the most part the only carb parts changed were the throttle shaft and float valve, gaskets of course. All of the jets etc were the originals with numbers stamped so I was able to compare these with charts on Vince's site. Dave at Renner's Corner supplied the needed parts. I had the filter and electric fuel pump from a Weber setup that I have and not using it currently. There is no internal filter in my B carb and I wanted a decent filter so that's why I went that direction. Here's some before and after pics. The evaporust did a great job removing all of the rust... wish I had taken pictures before I painted.

[ron103140]

I am running a B carb with a B intake that stalls at every stop. Carb was rebuilt by a very good rebuilder. No exhaust or vacuum leaks. High 5.5 compression head. What else can be done to correct the stalling? Ron

[Terry, NJ]

This is exactly what the B carb was supposed to solve. A B float operates cross wise to the A s fore and aft motion. I can only suggest cleaning it out thoroughly and checking/resetting the float level. All Mod. A s have a problem with rust in the tank and the resultant stalling. I would dump my sediment bowl and see whats in there. Then move downstream. One tip off is when your tank shut off valve feels gritty and hard to turn. You'll need a tank filter (inside the tank) Brattans 2017 pg 62, $4.35 each. Good luck!
Terry

Originally Posted by ron103140

I am running a B carb with a B intake that stalls at every stop. Carb was rebuilt by a very good rebuilder. No exhaust or vacuum leaks. High 5.5 compression head. What else can be done to correct the stalling? Ron

[RawhideKid]

Originally Posted by ron103140

I am running a B carb with a B intake that stalls at every stop. Carb was rebuilt by a very good rebuilder. No exhaust or vacuum leaks. High 5.5 compression head. What else can be done to correct the stalling? Ron

Lower the fuel level in the bowl.

[mngreen]

Originally Posted by denniskliesen

Follow-up on the results with the B carb...

Soooooo, how does it run?

Certainly looks good!

[denniskliesen]

Originally Posted by mngreen

Soooooo, how does it run?

Certainly looks good!

Runs better so far, much better than the Weber. Something I was surprised to see When I was checking things under the distributor cap was this... Where did this come from? The only pieces removed from the Weber were the accelerator pump and diaphragm and the air cleaner and base. So I'm thinking somewhere on top of the carburetor. Too many parts on the Weber. So if there is a Weber expert out there please let me know if you can where this might go. The carb kit parts paper that was in the package is hard to read and decipher what parts are which.

[GMCPASO]

Does anyone know why the B intake manifold it flat on top. Is there an advantage to this, is the manifold runners larger than the A manifold. Or was it just a place to set your food to heat up while traveling.

[denniskliesen]

Heating food up, I'll have to try that. I think we can only speculate why it is flat on top.