Mystery Motorcycle - what is it?

[hennesse]

What the heck is this thing?

A Henderson owner in Austria sent me this picture gallery of a 2019 antique motorcycle meet/ride at Grundlsee in Styria, a province in southeast Austria.

Scroll down five or six motorcycles, and you will find two photos of a bike named "Rusty Arrow". It looks like a WL / WLA bike, but with K-model heads. Or maybe it's a WL chassis with a K model engine grafted in, and a useless tank shift. Or maybe it's a ______.

Brain explosion imminent - HELP - what is this thing?

[Maxcapacity]

It looks like a 45 magnum to me. 45 lower with KR top end.

[panic]

"45 Magnum" was invented (???) by Randy Smith about 60 years ago.
900 XL top end on WR lower: lots of heli-arc and machining, frame mods. It's not faster (but far less reliable) than a stock XL engine.
Yes, it blew up. I saw it in pieces when I visited his shop in Cali.

A K top on 45 looks easier (no welding, frame OK), but major VT alignment problems, $$$.

[Ferrous_Head]

You could of course go the other way and graft a flat head top end onto an XL bottom end.



Probably a lot more reliable than the vice versa situation.

[themike]

knew a guy that put shovel heads on a Flathead 74. Ground his own cams. Saw him riding it all over.

[hennesse]

Just noticed - it's definitely a KR top end. The exhaust pipes go into the cylinders, not outside like production K/KH. Plus, who else but a crazy racer would drill all those holes?

[hugoct]

I doubt that the nightmare pictured would have been created by a racer.
AMA rules regarding racing specifically required that the manufacturer's crankcases, cylinder/s and head/s from the approved model be used.
There was even a memo sent to all AMA referees that addresses the KR cylinders on WR question.
This bike is a Euro Custom.
Some of the European customizers put style points before function.
Modifying a bike so that it stops, accelerates, corners, and goes in a straight line better than stock does not seem to be their goal.

[panic]

graft a flat head top end onto an XL bottom end
45, WR, K top on XL bottom: easy
VL, UL top on anything else: not

The question: how do you make the valve stems land on the XL cams...?

[Ferrous_Head]

Bifurcated push rods.

[panic]

1. shorten the valve stems as needed
2. fabricate some method to capture the upper end of the new pushrod at the stem end
3. lower end of PR is a std. ball
4, use XL/OHV style cup adjusters

Could it work?
How large is the misalignment?
Large error means huge side thrust vector.