175 Head With Two Spark Plug Holes

[skipperclyde]

I recently came across a Penton 175 motor, with a head, that was manufactured with two spark plug holes.  By looking at the castings this was part of the original casting and not added later.

The head and cylinder appear to be a long piston style with the tall cooling fins on the head.

I was wondering if this is common as I have never seen one like this before.

Thanks

SkipperClyde