Dear Friends
Having just recently started the search for setup of the RO-Jett .76 in my MC-72 airplane, I am of course very much interested in what others flying the same engine may have found so far. May I therefore kindly ask the community to comment on the numbers I am using at this point in time?
Site height above sea level: 1’300 ft, Temperature: 70°F
Airplane
Area 720 sq in
Hinge - hinge: 20 in
Empty Weight: 66 oz
C.G.: 22% MAC
Rabe Rudder max deflection: 1/2 in
Lines & length: 0.018 braided, 66.5 ft eye-eye
Line rake: as per LINEIII, fuselage flies tangential
Power Train
Motor: RO-Jett .76 RE (2006)
Compression: Factory std.
Venturi: 5.5 mm or 0.216 in
Airfilter: Bru-Line black (coarse)
Pipe: Brian Eather .76 3-chamber, set to 20 in, short ˝ in. deflector
Propeller: Brian Eather 2-blade, flat, square tip, 15 x 4.75 (pitch at No. 10 Prather)
Fuel: 10% nitro, 20% “Aerosave” synthetic oil, 70% methanol
Plug: Merlin, type 2003, hot
Setting & flight data
T/O RPM: 8300
Lap: 5.2 sec
Consumption:182 cc or 6.4 oz for 6:30 run time
Run: rich 2-cycle with occasional 4-cycle burst in level. Rich 2-cycle in manoeuvres
Level line pull: a lot (According to LINEIII: 5.7 Kg or 12 pound)
Overhead line pull: sufficient but not really overwhelming
Wishlist (as usual...)
More overhead pull
Slower lap time (5.5 would be nice)
Thank you and best regards from Switzerland,
Peter D. Germann