O.S. .55 HZ Heli Engine; Unleash the Beast
Posted on November 9, 2009 by aaronredbaron
With the recent release of the new O.S. 55 HZ Helicopter engine, heli flyers have another option to make their .50 sized helis rediculously powerful. O.S.’s new .55 is among the new breed of larger engines for .50 sized helis. The trend started with the release of the .53 Redline from Thunder Tiger, and more recently the KME .60 which is made in California. YS also has a .56 hitting the market, and all of these are hot contenders to make the most out of modern 50 sized helis.
More Power And Better Fuel Economy
Surprisingly, running the larger displacement engine produces not only more power, but delivers longer flight times compared to the popular O.S. .50 Hyper. A lot of it has to do with the 3 needle carburator, which allows better tuning over the midrange. In addition, the .55 doesn’t have to work as hard to maintain rotor speed. Where as the smaller displacement engine delivered adequate power for most regimes of flight, it was running at the raged edge all the time to produce the power most 3D flyers demand. This also contributed to the Hyper .50’s notirious issue with bearing failures. Having more power available actually reduces fuel consumption and makes power delivery more consistant. Rumor has it engineers at O.S. also attacked the bearing issue for this high performance engine. Only time will tell if the bearings hold up as users burn fuel, but the engines are already hitting store shelves, and I got my hands on one to try for myself!
Free Flowing Muffler
Muffler options for the newer, larger breed of 50 engines is limited, especially if you want to extract the most power out of the engine. The KME .60 deals with the demands by using a 90 sized muffler, but the rest in the class still use 50 sized pipes. The .55 HZ will probably run decent with most high performance 50 sized mufflers, but cheap restrictive mufflers are likely to make it run poorly and heat up. Initial reports indicate the Align 50 size pipe, and the CY MP5 SB pipe produce excellent power with the new .55. Hatori also has a pipe especially for the new O.S. and YS called the SAB-56 (for the US market). O.S. has their own pipe for the new engine, the O.S. PowerBoost 50/55 Hyper Heli Pipe, and a very similar pipe is available from FunTech, the A395.
Bigger Blades
Many of the 50 sized helicopters on the market will handle larger rotor blades than the common 600 mm size. The Raptor 50 Titan SE, Hirobo SDX, T-Rex 600N, and others can handle up to 620 mm rotor blades. A few, like the new Outrage Velocity 50, are able to swing 640 mm blades. While an O.S. Hyper .50 is best suited to 600 mm blades, many of the 50 size helis fly very well and auto exceptionally with larger blades. Running even RotorTech 610mm blades on a T-Rex 600N with the O.S. .50 is pushing it a bit if you are looking to get the best power, but the model flies very well. Going to the bigger engine makes the bigger blades a more practical option, and the bigger blades reduce the disk loading of any heli.
Making 50’s More Attractive
While a 90 sized heli is still a great option, the fuel costs are more prohibitive to some. Running an engine like the O.S. .55 HZ makes a high performance, efficient 50 sized heli an even better option than before. While its certainly not required unless you demand the highest degree of performance, most heli pilots are always on the quest for more power! Check back soon for a full report on the new O.S. .55 HZ installed in a Raptor 50 Titan SE with a Funtech A-395 muffler. For now, enjoy this video of Bert Kammerer beating the daylights out of his T-Rex 600N with the new O.S. in it.
