Info needed: Help to identify my engine!

[Paul Singleton]

Your 3.6 litre, or 221 engine was known as the 81A and was a 24 stud engine manufactured from 1938 until 1942. To my knowledge it can’t be bored enough to create a 239 engine. Some 99A Mercury blocks from that era have thicker cylinder walls and can be bored quite a bit over size, but are 239 cid to start with, but are fairly rare.

[Alastair Thomas]

Thanks Paul.

[Lynn Eades]

Hi Alastair. Go to VanPelts v8 website to identify your motor (at least the American versions) Hunt on the web for info on how to I.D. your motor. Most Ford V8s of the era were 3.6l (3 1/16" bore) or 3.9l 3 3/16" bore. I believe you can bore the small engine to a max of 3 3/16" (0.060" o.s.) however you are better to find a good later model block to start with, in my opinion
If your motor is a British 21 stud they were rated at 60 h.p. (18mm spark plugs?) Without checking, I believe these motors had thrust faces on the big end shells. I dont know if that was all of them.
Anyhow, The camshaft could have a bolt on gear or a pressed on gear. If it is pressed on your only way to alter the valve timing is either strip down or to drop the sump and remove the crankshaft gear. Not much fun. It should have a bolt on gear either Iron or Alluminium.
Another minor problem you might have is the cam profile. From 1942 on the Canadian engines for heavy trucks were fitted with a C59T camshaft. (Improved torque) (this is not your main problem)
Btw. A C21A engine is a factory 3 1/16" bore.
I have a C59 engine (first produced in mid 1941) I have bored it to 3 5/16". It goes well (It's in my Bren carrier)