No takers?
I've got to say, I would never have guessed at it myself either.
It's a Briscoe, which I had never heard of until I asked the owner. Benjamin Briscoe had been an industrialist supplying parts to the auto industry from the earliest days. He also loaned money to Buick to get started.
From around 1912 he started making cars himself, including having a foray to France to make them at Billancourt. Plants at Jackson, Michigan and in Canada. They were able to approach or surpass an annual production of 10,000 several times.
In my estimation, the engine above dates from the French era, but I could be wrong. It's sufficiently 'odd' to be French with monobloc construction and what appears to be a fairly small capacity (oddly, the smallest engine I see mentioned in my reference works is 157 cubes, I don't think this engine is that big).
But one thing is for sure about Briscoe... change was a regular thing in their production. John Ryder of Coonabarabran heard of this one and rushed up to buy it as spares for one he has... and everything about it was different.
Among the various different Briscoe engines there was also a V8. I wonder if it was one with two 4-cyl blocks bolted together at the crank centreline? Shouldn't really ask such a question on the Inliners forum, of course.
An easier one:
