BB18 Flathead ?

[Prawbly]

I read a post where a guy had a 21 stud BB18 flathead. Then someone said it's not a 21 stud it's a 24 stud. My curiosity was raised because on the top of my block right near the intake is BB stamped on my block.
Before this I have never heard of a BB block anything let alone 21 or 24 stud ! My block is (Thanks to Barn members) a sleeved 221, that has had the sleeves removed and bored .040 over, With 24 studs, great motor, just completing installing new valves, cam, intake , heads , headers.
I looked on Van Pelts site and couldn't find any info on a BB block. Any guys know anything about this engine ? I am really curious. I realize
there could be stamped numbers, letters all over engines over the years, but I am curious about this engine. What numbers designate a BB 18 ?
Thanks Pat

 

[DavidG]

None with 24 studs.

 

[rotorwrench]

The only thing that I can recall FoMoCo using the BB prefix on was for trucks. They continued the practice of truck designation as was done with the Model AA trucks in the model A era 1928 thru 1931. When the model B four cylinder came along in 1932 the trucks took on the Model BB designation and a lot of the parts for trucks used this prefix for a number of years after. Now a V8 had the designation "18" starting in 1932 so there is a possibility that a truck with a V8 may have "BB" in associated with "18" but I don't know. Trucks used BB as a model designator until 1935 when they started to differentiate between the various types of trucks available. The information on identification of trucks is less clear than it is for passenger cars.

As far as stampings on engines are concerned, it may be possible that a state required stamping of an ID or VIN on the engine block but BB would not have been used much passed 1934. Trucks had taken on new model numbers in 1935 and the 24 stud V8 blocks didn't show up until 1938. By that time the BB designation was pretty much gone except for just a few chassis parts that had not changed to later types yet. LB was stamped on blocks in the late 1935 to 1936 range and 99 was stamped on some early 239 24 stud engines but I don't know of a BB stamping unless it was an inspectors stamp or something of that nature. Blocks have a lot of little inspection stampings but no one seem to know their meaning other than the date code stamping on many of the later blocks.