Sort of weird....

TopBannana Wed Feb 18, 2015 7:07 am

Would this so called "MIXED UP" engine that has a rr1 crank case have a rotary valve or a reed valve? :

http://www.ebay.com/itm/MIXED-UP-COX-049-model-airplane-engine-/111597081058?pt=LH_DefaultDomain_0&hash=item19fbb451e2

Trevor

microflitedude Wed Feb 18, 2015 8:20 am

It would have a reed valve as that tank is off a Golden Bee with a Kavan tank extender. The RR1 tank is specially made to accommodate the disc valve. You can tell them apart superficially from other standard stunt tanks by looking at the machined ribs. (like the crankcase)

Somebody had the gold parts and thought they would look nice together. The crankcase is the only RR1 part I see on there.

roddie Wed Feb 18, 2015 2:18 pm

Another point is; I believe that a "stock" RR-1 crank would have a "crank-pin" that is too long for a Bee-style tank to fit into the case. (the reed-housing would hit the longer crank-pin.) I don't know if a stock "Bee-style" crank will fit in an RR-1 case either.. but that's basically the only way that this engine would run.. as a reed-valve induction engine.. as Matt stated.

It's possible that someone ground the RR-1's crank-pin shorter.. but I honestly can't see why anyone in their right mind would want to do that. Possibly it was an "orphaned" case assembly.. and they liked the looks of it with the Golden Bee tank. I don't care for "looks" of the black tank-extender and frankly.. I don't know where they would have gotten 2-56 screws long enough to mount that 8cc tank and extender to the case. Those glow-plug conversion heads (for fitting a standard glow-plug..) almost always yield a drop in performance.

pkrankow Wed Feb 18, 2015 3:26 pm

My bet is someone had a crank failure and wanted to reuse the case since RR1 cranks are unobtainium. Hopefully the winner will post about it here.

Phil