Dumb question of the day...
What is the thread size for the screws that hold the cam cover to a 1937-1948 engine case ?
I’ve tried 1/4-20 and 1/4-28 and neither fit.

 

Cam cover - lifter blocks - distributor screws and voltage regulator mount - trans mission top cover - i might have forgotten one or 2 — 1/4 X 24 its a special thread colony products carries everything for the early machines

 

Hi John, I’ll check out Colony, it figures it would be an oddball size.

 

It's a bastard thread for sure. Colony sells both that and standard so read carefully.

 

The cases are Cannonball reproduction out of Germany, they wrote me back and said that the threads are 1/4”-24 and suggested
the Colony, I have brand new set of Colony 8149-12 but they are slightly too big, the Colony package doesn’t say that they are 1/4”-24 but rather they fit 1936-1969 big twin.
Do you happen to have the Colony part number for the 1/4”-24 ? I couldn’t find one in the Colony catalog.

 

I dont have the number sorry. I know I got a set once that was the wrong thread and they're now in a bin of hardware probably lost forever.

 

I’ve got those bins all over my shop :-) Thanks anyway.

 

It’s the same screws for a knuckle in park

 

My knuckle doesn't have park, just 4 speeds and neutral.

 

Problem solved.
It looks like Cannonball does their bead blasting after all the holes are tapped and are a little rough.
I didn’t want to force the Colony cam cover screws into the holes because the package didn’t say they were “1/4”-24” only that they fit 1936-1969 big twin and they didn’t feel right to me.
I ordered a 1/4”-24 tap which came today and it matched the Colony screws, I chucked it up in a old drill chuck I had laying around and it cleaned the holes up easily with a little oil by hand, it took almost no effort so I knew I wasn’t cutting a new thread.
The Colony screws fit perfectly now.
I’m just farting around doing a little test fitting on the engine parts I can’t fully get started until I finish the 31 hot rod I’m building.
Here’s a question for John or anyone else who has an opinion.
The tappet blocks are very tight and will only push in around a 1/4” or so, how tight should the fit be between the tappet block and the engine case ?
Here’s a couple pics from today.