Model B Carburetor

[JimK1930A]

Hello,
I am seeking information about the Model B Carburetor float shape.
I read and looked at Vince Falters web site about the different shaped floats.
Is there a preferred float shape Round verses the Rectangular float with spring?
I know they changed from round to rectangular as the years progressed, so it got me thinking is the rectangular float a new and improved version?
If so, what is the improvement?
Thank you,
Jim

 

[jim1932]

I have several "B" carbs and all the floats look like this...... I understand there were different variations however.

 

[pat in Santa Cruz]

I'm not familiar with which is preferred. But the idle jet hole on the later caburetors with the rectangle float is supposed to perform better. If you use the spring loaded float on an A, remove the spring.

 

[ursus]

A couple years ago there was some discussion here about the conversion to the later rectangular float and spring assembly, but most of that centered on the reason for the spring. There was no reference to any documents from Ford regarding this change in the B-carb. Somebody offered the opinion that heavier round floats were more susceptible to the effects of motion and vibration and that the lighter spring-moderated rectangular float improved the B-carb performance at higher speeds on curvy roads or in stop and go driving situations. The square float might also have more of a damping effect on the sloshing of fuel in the bowl. However, beyond theoretical physics, nobody reported that one worked any better than the other in their own experience.

This change took place at a time of significant change in automotive carbureter design, so maybe the newer float assembly was simply a part of that evolution. Was there a good reason to put fins on cars in the 1950's?

 

[JimK1930A]

Thank you Ursus for the detailed information.
It is interesting to know these facts and ideas.
Jim

 

[Ron in Quincy]

The round float was used in 1932 Carbs. The 33-34 B Carb. has a cast baffel inside the bowl and uses the flat style float.

The spring and baffel plate in the 33-34 Carbs. was to assist shut off of valve do to the full pump pressure.

If using the 33-34 B Carb on a gravity feed Model A the spring and baffel plate can be removed and will have no effect on the operation of the carb.

Ron

 

[Bruce Lancaster]

I once tracked this stuff through several early V8 catalogs...don't remember the dates these things appeared, but:
When the small square float replaced the round one, it appeared in the parts catalog only as an assembly, installed on the bracket with spring and baffle. Later, the float by itself appeared in the catalog alone as a replacement for both early and late. I have seen a number of B carbs with late float and no baffle, and assume these were assembled so by rebuilders using the float available from Ford.