I'll just imbed my answers after Tracy's:
In a message dated 5/2/02 4:47:01 PM Central Daylight Time, rotaryeng@earthlink.net writes:
Tracy Crook wrote:
See answers imbeded:
David Mix wrote:
Hi Paul,
Perhaps you or an ACRE reader could answer some basic questions for me.
1.) Where do NEW 20b's come from? i.e. U.S. distributor name.
No such thing. Engine builders like Bruce Turrentine can build them from
parts though.
To the best of my knowledge and based on the 2 years of research I've done, there are no NEW 20B's being made currently. I may be wrong about that, but I do know that good used "true 20B engines" are available for import from Japan, New Zealand, and Australia. That's where I got mine from (New Zealand). Mine came as a COMPLETE ENGINE with ALL external components. Most U.S. builders modify a 13B by changing the
e-shaft and stacking on an additional Rotor to effectively make it a 20B. This is just fine for our application since ~95% of the "longblock" parts are interchangeable anyway. The external parts of a "TRUE 20B" are mostly worthless to those of us building aircraft engines. I didn't realize this when I first decided to import a complete engine. I chose this route because I could buy a complete engine with all external components (including Turbos), ship it to Dallas, and rebuild it myself for less than half the price I was quoted by one of the reputable builders. Since that time I have seen other builders price their rebuilt 13B to 20B conversions for a price comparable to what I spent (so shop around and talk to a lot of people before you buy anything). I striped off all the external components like the turbos, flywheel, starter, electric oil injection metering pump, exhaust manifold, oil pan, coils / ignitor modules, air pump, water pump, etc., and have never used any of these items. I made a carbon fiber oil pan using a "High Temp" epoxy, but I did use the alternator, fuel rails and injectors, stock intake manifold (highly modified and lightened) and throttle body or at least I'm using them for now. I may end up using only the lower part of the intake manifold and making carbon fiber runners for it. Still to be determined. If you do decide to import a real 20B, avoid the guy a www.3rotor.com I had a bad experience with him. I know he is listed on the ACRE website, but this doesn't make him a reputable business man (at least my experience with him). GOOD LUCK in the search!!
2.) Are 20b's available without EFI, as RWS has that base well covered?
See above
I'm using Tracy's EFI/EI (EC-2) also. In fact, I've been working on wiring it up over the last week or two. David Atkins also offers an EFI system but I don't know anything about it. I think Tracy has a good system and I'm still hoping he will complete the "EC2 engine monitor accessory. Displays will include fuel flow, fuel totalizer, RPM, manifold pressure, MPG and other engine parameters". I know many of us are eager to get our hands on something like this!!!
3.) What's the price?
Contact Bruce
I bought the complete 20B for $3000 which included shipping to the Dallas warehouse, but it took ~3 months to get it. It cost me about another $50 to get it through Customs. The sky is the limits once you start the rebuild. I recommend that you tear down ANY engine even if it runs great. Get the Bruce Turrentine rebuild video. Its really for a 13B but its still a great resource for how to clean up, assemble, and measure wear in the engine, etc. If you don't have any trashed rotors or housings, a rebuild is pretty cheap unless you get carried away with expensive porting, machining, and modifications. I figure that my normally aspirated 20B without any added porting or mods will produce 220-240 hp which is more that I really need anyway. I can always get fancy later down the road if I feel its needed.
4.) Who has - or is developing - a PSRU for the 20b?
We (RWS) make the RD-1B for the 20B engine (up to 300 HP continuous)
Enough said !!! That's what I'm using too!!! Beautiful piece of work!!
6.) What are the overall "box" dimensions from the prop flg - l,w,h? and
wet
+/or dry weight?
Bare block 20B weighs 247 pounds.
7.)Does anyone have speed/torque curve for 20b's - N/A and turboed -
preferably at the PSRU prop shaft, maybe even overlaid on a LYC IO540
curve?
This seems like the closest std catagory A/C powerplant for comparison.
No realistic curves available in our application & configuration. Your
comparison is a good one. Think of 20B as an IO - 540 replacement and you
won't be dissapointed with the power
Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.co
m
Don Mitchell
Std-FG Velocity / Mazda 20B
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