A strange olympic...any idea what it is?

That's an interesting one, alright. I hope you'll make a video when you get it running.
Good luck.
Rusty

Cribbs74 wrote:What's the story behind the box of engines?

The workshop seems to be filled with engines, most sitting in 'cold storage' mode. I'd say this box was from one of the senior instructors, who decided to store, or possibly donate his engines which "i don't use anymore". There are a couple of drawers with engines that look like they have never been run in years, or run at all! We even found a turbine engine in a shoe box ....

Mudhen wrote:Does it have a smaller pin machined onto the crankpin to match against the rotor? If so, it’s unlikely to be homemade.
Closer, more detailed pictures would be helpful.

The crankpin does have a smaller pin machined onto it, and it does match against the rotor. The 'bearing tube' in which this rotor sits in is also a separate piece and can be removed from the aluminium end cap. It fits the screw-on back plate perfectly and even has a pressure tap hole(?) on one side. It also has some pattern rolled into it, presumably for a plastic part to fit on it. I didn't take many photos of it's insides but i do have a somewhat close up of the rotor.

RknRusty wrote:That's an interesting one, alright. I hope you'll make a video when you get it running.

Thanks!, but i doubt this engine will run in its current state. When i found the engine, it had metal filings inside, mostly around the drum valve and its bearing, the drum valve/rotor looked unharmed, but the bearing had filings around intake hole and the rotor had a rather tight fit inside the bearing. I assume during the drilling of the intake on the new end cap the bearing was left inside the end cap, and ended up getting drilled out/bent in the process, which would explain the damage.

Tim Here is a link on that engine from some time back .. Mudhen Knows his stuff on Cox engines !!

https://www.coxengineforum.com/t4131-15-rotary-drum-bill-atwood?highlight=olympic+++15

micro 0951 wrote:Whilst digging through a box-o-engines at my workplace, i came across an engine. Its an olympic, missing parts and seized up. Whats peculiar about this engine is its rear end. Instead of the red venturi assembly it had some cylinder in its place. Could it be the rare drum valve version of the olympic?

Hey Tim,

Everything other than the Rear Carb Body looks to be a genuine Olympic Prototype, type B. It looks to me like someone broke the fragile carb body on their engine and tried to make a replacement from aluminum.

I noticed that you said that you were digging through this box at your workplace. Where do you work and what do you do?

If you haven't already seen the additional information about the Olympic Prototype engines on Martin Hepperle's website, the link is below.

Details about the Olympic Prototypes from Martin Hepperle's Site