Piper PA-18 Super Cub IO-390 STC
210 HP Conversion - The Ultimate Super Cub Upgrade. We call it: The King Cub.
King Cub IO-390 Conversion Kit
The King Cub IO-390 Conversion Kit is everything you need to convert any cub into a King Cub. The upgrade is STC approved and increases performance, with minimal weight sacrifice and better fuel economy. With the King Cub upgrade, your Cub will experience shorter takeoff, faster cruise speed, better float performance and much smoother operation.
Comparison: Lycoming IO-390 vs. O-360
Much smoother operation - Feels like a turbine with the roller tappets and cam and counterweighted crankshaft.
Fast, powerful, with very little weight sacrifice over 180 hp engine - Compare engine weights:
Lyc. IO-390, 210 hp...308 lbs.
Lyc. O-360 "A" series, 180 hp...285 - 301 lbs. *
Lyc. O-360 "C" series, 180 hp...285 - 290 lbs
Fuel Injection allows for better fuel economy than 180 hp engines
Fuel burn almost identical to O-360, 180 hp engines @ the same hp output.
IO-390: 146HP...10.4 GPH
O-360: 126HP...8.8 GPH
Faster cruise speed - 115 mph TAS @ 25 square
Amazingly shorter takeoff distance
Takeoff distance, ground roll...75 ft.
Takeoff distance, 50 ft. obstacle...225 ft.
Much better float performance - Climbs at 1000 fpm (tested on Wipline 2100 amphib floats)
Increase aircraft's value - A factory new or rebuilt engine combined with a horsepower increase offers a significant increase in the aircraft's value
The King Cub IO-390 Conversion kit contains:
Lycoming IO-390-A1B6 engine
MT MTV-15-B/210-58 Constant speed, composite propeller, 82.7" diameter
NEW! STC Approved MT MTV-15-B-C-R(M)/CR210-58 Reverse prop now an option
MT Prop Governor, P-860-3
MT Spinner, P-277-6
New dynafocal engine mount - w/ new Lord mount bushings
New Weldon electric fuel boost pump
All new engine baffles to fit the IO-390 / Piper combination
Two new oil coolers
New lightweight alternator
New lightweight starter
New SlickStart Magneto Booster system (req. as the IO-390 does not come w/ impulse couplers)
All new exhaust system
New nose bowl and complete cowling assembly
New Alternate Air Box
New Brackett Air Filter assembly and element
All new control cables and brackets (Throttle, Mixture, Prop Governor, Alternate Air)
All new fuel lines, hoses and hardware for fuel system assembly
All new oil lines, hoses and hardware for oil cooler plumbing and ducting
New placard set
Other miscellaneous hardware necessary for the conversion
All STC paperwork
Required items: To see a list of items that are required in order to install the conversion click here (PDF).
This kit may be performed on brand new aircraft bilds, FWF installs on an existing aircraft, or purchase our kit and have your A&P install it for you.
King Cub Wins Gold At Takeoff Competition
We placed first with the King Cub kit during the 2010 Greenville, ME International Seaplane Fly-In.