The Ford Barn - View Single Post

gz · 10-26-2020, 06:09 PM

Tough to tell a B from a BB. All the Model Bs that I have seen had embossments for the second set of spark plugs on the intake side so someone could easily drill and tap them if desired. I believe the real difference between a B and BB is higher compression and maybe larger valves..

Fortunately, it looks like your head has not been milled much since there is still a lot of meat between the recessed spark plug holes and the bottom of the head.

It does look like the valves and valve seats have been enlarged because there is very little meat between the two valve heads. From the pictures it looks like they are very close to touching! Be very careful here, especially if you are going to do a valve job or any type of work on the valve seats. This looks very fragile. If you are doing valve work, just gently touch up the valve seats with some hand lapping compound- I wouldn't go anywhere near a valve grinding machine.

From what I can tell, your cover is a replacement. Hard to describe but the originals just have a different look. If the casting is rough underneath, it is probably newer. Not a big deal either way and I wouldn't worry about it.

Looks like a great head. Original exhaust manifolds are hard to find. Congratulations on your purchase.

10-26-2020, 06:09 PM	#2
gz Senior Member Join Date: May 2010 Posts: 1,666	Re: Rajo BB head Tough to tell a B from a BB. All the Model Bs that I have seen had embossments for the second set of spark plugs on the intake side so someone could easily drill and tap them if desired. I believe the real difference between a B and BB is higher compression and maybe larger valves.. Fortunately, it looks like your head has not been milled much since there is still a lot of meat between the recessed spark plug holes and the bottom of the head. It does look like the valves and valve seats have been enlarged because there is very little meat between the two valve heads. From the pictures it looks like they are very close to touching! Be very careful here, especially if you are going to do a valve job or any type of work on the valve seats. This looks very fragile. If you are doing valve work, just gently touch up the valve seats with some hand lapping compound- I wouldn't go anywhere near a valve grinding machine. From what I can tell, your cover is a replacement. Hard to describe but the originals just have a different look. If the casting is rough underneath, it is probably newer. Not a big deal either way and I wouldn't worry about it. Looks like a great head. Original exhaust manifolds are hard to find. Congratulations on your purchase.