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Discussion in 'Rotorcraft' started by Blue Chips, Dec 30, 2014.
Thanks for the info, I think I'll keep flying what I have for a while.
300+ hp in a Rotoway? Wow. Cant use it all the torque for sure.
C-18 has about -250 hp the later c-20 +270 hp c-20B 300 +- torque/temp. c-47 500+ If you don't care of the torque limit it will pull 1,000 hp for a short time.:whistle:
temp is an engine limit/ torque is an airframe limit.
For the -700 I thought the derated hp was about the 250 but the "free" hp was 315. Even at 250 its double what the airframe was designed for. My company 480B with the C20W is derated 277 continuous, 305 for 5 min, and will go 420. The torque meter is calibrated so 100% is 420hp; 277 is about 65% which is top of green. An engine that will fly a 2800 lb helicopter in a 1500 lb one would be exciting. Get sloppy and shred some parts from overspeed or over torque.
the red lines on the 250 series TO power is mostly listed as it's a higher 5 minute rating to sell the product, the continuous power is lower, C-20 W is the latest and greatest.
We had a 206 A with a C 20 B and a few other up grades, It would go anywhere but you could tell the torque limit as the gearbox would howl right at the last bit of yellow on the torque gage.
C-20 B 285
if you had a miss matched compressor/ turbine you could lose 40% of rated power, the pressures and flows were important some times you'd change out a maxi turbine just to match for better performance and nothing else as all the pieces where fresh...
If you had the light weight & power you would have a nice rocket, Had one owner of a jet exec cruise at 120 mph all day long, seeing him fly it was like it was a rocket sled on rails.
Other than a complete tear down, how do you get rotating component ser. Ns? Turbine wheels are believed to be a later batch than those with the serialized limits. Fuel consumption with one up and hovering hasn't got to 12gph yet. Spurling had a guy flying up and down the runway putting time on the bird for the 40hr. The guy said the fuel consumption always checked out at right at 10gph. Yep am running above flight idle at what is indicated at 85-90%. Definitely has governor action. Also has the rotor speed nudger for fine tweaking rotor rpm. Torque never exceeds 40 psi. I thought the Solar specific fuel consumption was about twice that listed for the C18. In fact the spec sheet I've got shows the T62-32 specific consumption to be 1.3#/shp/hr with the C-18 at 0.7#/shp/hr. It would seem that for the same power produced the C-18 is much more frugal on fuel than the Solar. Looking at old specs the Jet exec should need something more than 100hp for two up? that is 130#/hr which @ 6.7#/gal for Jet A looks more like 19.4 gph for the T62!! Do you have some other numbers? Spurling got two birds out and then went thru a divorce that pretty much stopped his action. There is another one like it being built by a guy who lists on the Rotorway owners group by the name of Mancini. He has acquired a C-20 though. The other JT300 that has been operational is down now I believe with a transmission gear problem. They don't seem to be pursuing it very much.
If you ever go skiing to Mammoth, stop by there is a cold beer, a single malt scotch or a Crown Royal with your name on it. Stu
You can try using the engine assembly part & serial number and write the DoD for the records on the depot level maintenance preformed on it. It takes time but it's cheaper than opening it up. the jet exec had a 40 odd gallon tank and we had a good two and a half hours with reserve, full bag of fuel, two fatties and golf clubs in the rear baggage compartment...19.4 gph is a sign of a tired engine.
Dan: I'm missing something. A helicycle guy on this thread reported 13-16gph on his bird. How did you get 12gph on a loaded Jet Exec.? I compute, using published consumption specs on the T62-32 that 12gph is on an engine producing about 62shp. That doesn't seem to be enough for a fully loaded Exec. That 19.4gph is the fuel consumption of a T62-32 engine producing 100shp according to the mfr. specifications. What am I missing? I know that fuel consumption calculations can be misleading. I once topped off my Safari, flew 4 miles to IYK landed and shut down and waited for another bird, started and flew formation to California City airport for breakfast. Shut down and ate then started the bird again and maneuvered to the fuel pit. All I could get in the tanks was 7 gal. The Hr meter read exactly one hour. That told me, I thought, that my fuel consumption was 7gph. Thinking again, maybe the hour meter was powered by the master sw and not engine oil pressure. That would show more time than was actually accrued with the engine running. I found the Hobbs on my JT300 connected to the master sw. I've changed that to operate from the torque oil pressure. Again I've got something to learn if a loaded Jet Exec can operate on 62shp.
the T-62 T 32 has 150 hp available in it's stock form the FCU has stops for a lower HP when in the M 1 A1 gen set. but the fuel burn is 12/13 gph even with no load the pto is a solid 6000 rpm and free from any added gizmos, the Gear box on the heli-cycle is not stock adding a reducer and generator plus the oil scavenge is different along with the FCU drive, the stock T-62 T 32 having a wet sump. the Solar was so solid in RPM that we added a manual Governor override where you manually controlled the Rotor RPM even with all electrical power removed, It was so nice that the owner often flew it with the governor switched off. as I said the fuel burn & temperature are part of the health of the engine, in the 1990s the Solar was made a conditional use engine with no cycle or time limits other than overhaul as they kept going and going, If it made rated power within limits you kept it in service. If the fuel burn is off it's a sick critter and requires work. with 40 gallons we got two and a half hours plus reserve+ till sump level ( a gallon step sump for debris)
this execs SN#98 engine was from a fresh navy depot overhaul and not a surplus mishmash of parts from Avon Aero (great supplier) remaned in BJs frankinstine engine works (???)...
The jet exec was designed to take a stock T-62 T32 from the gen set to be installed straight with little mods (oil pressure gage, fuel cut off from electric to manual).
Why change what works...
I don't get it. Are you telling me that the MFR spec of 1.3#/shp/hr doesn't match actual practice? I had two of the things when I was building a Helicycle but sold them with the partially completed kit. (ran into to too many design things that I didn't like) I did get to run the one, with the stock gear box, that I had bought that had been recently Navy o'hauled. We put an electrical load on it but didn't look at the fuel consumption. Just enough load to ensure governor operation. We didn't have enough electrical load to get to the 150hp.
Dan: Did some more checking and found another Jet Exec reporting 13/14gph at cruise with a Bedo overhauled engine. I guess the slick Rotorway manages to cruise with something like 60hp being generated for main and tail rotors as well as the alternator. It will be interesting to see what the JT300 does in cruise.
Joe was a cool guy, (RIP) he did real good work even with the JFS 100s.
=homemade gyro and heli composites rotors...
the last picture on icz-helicopter, the blade has a skin and no structure/ spar, chord weight etc. what's up with that??? look again....
=it is BKB1 wing \NACA8-H-12, 1200 mm chord...\
=rotor blades have longeron + skin + stahl ballast=25 % =13 kg weight.
=2x 13,5 kW !
If what I saw in the picture was typical then an impact with a June bug will cause catastrophic damage...what cyclic fatigue life does it have? or was that a shot of a tail rotor blades tip? It looks too light in construction, it might not respond to cyclic inputs as the structure will twist to centrifugal moments and aerodynamic loads. looks like nothing there...All empty,
https://sites.google.com/site/stingraysphotoarchive4/_/rsrc/1454891262643/page-2/Wozowicz6.jpg this one
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