Twin Cam cylinder head question

[Sherman Kaplan]

Just curious, on the twin cam what is this threaded hole on the inlet side of the cylinder head for and why is it threaded?


thanks,
Sherman

[Lotuswins]

On my junk Stromberg head, it isn't threaded, and leads down into the breather chamber.  Probably to help the breathing/pressure buildup in the upper part of the head....who knows?  I do know they had issues in the early design but that was with webers......Perhaps a DPO threaded it to mount a dial indicator for cam timing?? 

Jerry Rude
4005R