Anybody know of any broken Os wankels for sale?

//Magnus

Hi, I've got a question for Volfy...What engine is that in your picture? ( I mean the conventional piston one) and where did you get that header? ( guess that's two questions) I've been trying to get ahold of Mac's and have had no luck! Is that a Mac's header? Thanks, Tom.

proptop, that's a Thunder Tiger Pro 1.20RP with a Weston (UK) fusetop header mated to a Mac's 25cc pipe (#1195). The "RP" stands for "Rear Exhaust" "Pumped". It's one heck of an engine. Last time I ran it, it was tuned to turn a MA Classic 18x6 at 9000 on 5% nitro. I will switch to a 17x6 or 16x8 for flying and expect to see 9500rpm with those props.

Mac's show 3 different headers for this engine in their catalog. I suppose you can order direct from them, but I ordered my pipe through LHS.

The unmuffled #1195 pipe is loud though, thus the rather odd looking "secondary muffler" in the photo above to appease my neighbors.

Volfy, thanks, I tried ordering direct from Mac's but the check hasn't been processed yet, 7 weeks later! Don't know wether to wait a little longer, or try someplace else...Maybe Jett, for a MVVS R. exh. fuse. top header. Maybe Weston has one (?) would you happen to have their site add. handy? Thanks.

Here are some pics of my aluminum Tatone engine test stand in action. The engine stand is bolted to a test bench made from oak bookshelves obtained from a local home improvement store.





Brand new YS 63 running super rich and smoking up the whole neighborhood:


The test bench is bolted down to my rear deck at all four corners using wood screws. This puppy isn't going anywhere.


The aluminum Tatone engine test stand can handle engines ranging from 0.3 cubic inches to 1.3 cubic inches.

This is all from memory but it was invented by Felix Wankel (from Germany?) who sold the rights to NSU who used it in their Ro80. After NSU stopped making them the rights were sold to Mazda. The rights to make small Wankel engines went to Graupner (I'm not sure what the upper limit for size was though) who were then approached by OS.

Are there any protections left on the design, patent wise? Seems like they were designed long ago.

Don't know what the duration is on international patents, but US patents last 17yrs, IIRC. The again, the typicaly trick companies do to extend the effective patent life is to make a slight modification or improvement to the original patent and apply for an extension based on it.

I bought the header, or "manifold" as it is called in UK, with my engine here:

http://www.sussex-model-centre.co.uk...asp?ProdID=940

Maybe you can look around and see if they have what you're looking for.