Model B Carburator

[rfitzpatrick]

I'm interested in putting the B on my A. Any suggestions plz.
Thanks

[alexiskai]

For performance improvement? Or just for kicks?

[daren007]

Tried it, Went back to the “A”.

[Oldgearz]

Have one on my 30 Coup. It runs great with good pick-up. Good luck!

[Jack Shaft]

Drill the center runner of your A intake manifold to 1.25" to realize any gain in performance from a B carb. The best thing is the port/starboard mount float valve, no more stalling on hard stops.

[BRENT in 10-uh-C]

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Bolting a Model-B carburetor onto a Model-A manifold gains little because of the draw-tube restriction of the manifold. A Model-A manifold has a 1.000" draw tube opening whereas the Model-B intake is 1.250". You can exchange the 'A' intake for a 'B' intake manifold however the 'B' has the flange skewed differently than what you find on the 'A', so that requires machining the flange holes to be able to rotate the carburetor. IMO, it is better to purchase/modify a Model-A intake manifold that has been machined oversized to reap the benefit of the larger throat size of the 'B' carburetor.

[Benson]

The B manifolds are skewed and require modifying the manifold flange as Brent mentioned above

Or if you do not want to machine the Model B manifold bolt holes, buy this modified bolt set.

Renners and Berts have them.

Description: ADAPTER FOR MODEL A CHOKE ROD WITH MODEL B CARBURETOR
Comments: Allows model A choke rod to connect with B carb on B manifold
Application: 1928 - 31.

[rfitzpatrick]

The best thing is the port/starboard mount float valve, no more stalling on hard stops.[/QUOTE]


OK, this was what I was looking for. I knew I would need to modify the A Intake too.


Thanks Guys

[Benson]

Excuse me ...

[jayvee34]

Originally Posted by Benson

Excuse me ...

From the other thread above named Zenith - 1 Carburetor

it looks like I am not "thee one to listen to about rebuilding Model A carbs".


What could I possible know about rebuilding Zeniths?

I restored 25 in the last three weeks and none of them stalled at a stop during the road test!



Xin lỗi

Being that you are an expert with these Zenith Carbs please read all the post
on this Zenith - 1 Carburetor thread and give a reason why this particular carb behaves as it does. It will be greatly appreciated. Thanks

[dave hummell]

I have a b zenith on my 31 along with a 6-1 head and an aries muffler I modified the a manifold. I wanted a better power band for the hills around my state and it does the job very well. I find the zeniths to have some quirks to them but remember when they were designed.

[john in illinois]

A friend bought 4 B carbs and decided to learn all he could about them.
Renner’s Corner has rebuild parts and instructions . They have drawings for all the special tools you need. I made some of these in my shop.

He has been on this quest for about a year and has never had one not leak,so he is throwing in the towel on Model B carbs. They run great for him,but leak.

John

[Gene F]

Originally Posted by dave hummell

I have a b zenith on my 31 along with a 6-1 head and an aries muffler I modified the a manifold. I wanted a better power band for the hills around my state and it does the job very well. I find the zeniths to have some quirks to them but remember when they were designed.

Dave, on a hill when you retard spark, what typically is the open of the GAV knob? I have g\just gotten a new engine with much the same setup as you.

[redmodelt]

Xxxxxxxxxxxx

[AL in NY]

I rebuild "B" carburetors. They perform great but they have to be rebuild correctly. This means they should be totally taken apart and ALL the internal passages cleaned and the passage plugs replaced. You do have to be very careful removing the brass GAV screw. And when it's replaced use a gas resistant non-hardening sealer on it to prevent leaks.

[29spcoupe]

I have a B carburetor, ported A manifold, and Snyder's head on my coupe. Couldn't be happier with it. No leaks.

[dave hummell]

Gene F my gav is about 1/2 turn and I don't pull the spark advance lever down anymore than 9 oclock position.

[Ed in Maine]

I have a B Carb on my 32 Model B. It is not as much fun to use as the A carb. Per the Ford Service Bulletins, the GAV is to open only on a cold start and then closed. If it is open some all the time, it will be running rich. Part of driving the Model A is the experience of adjusting the GAV for the best performance. Ed