First Flight of a Bentley BR2 Rotary Engine

A bit of modeling history was made on December 4th when Robert Cooper's twice-size model of Lou Proctor's "Antic" took to the air powered by a Blackmore-designed Bentley BR2 rotary aero engine. Dubbed the "GIGANTIC," Robert's aircraft lifted off at Hodges Hobby Shop (Andersonville, GA) at about noon with Mac Hodges at the controls. The engine and plane performed flawlessly, and although it was in the air for only a few minutes, we believe it may have set at least two world records. As far as we know it is the first model Bentley BR2 to take flight and the first ¼-scale model rotary engine to power a model airplane into the air.

Robert Cooper designed and built the aircraft, and Paul Knapp built the Bentley BR2. Ray Williams developed the fuel control system and assisted in all aspects of the engine installation. Ray Williams was the first person to successfully fly a model rotary engine when he flew his 1/3 scale model 160 HP Gnome in December 2001. His Gnome engine is on exhibit at the Craftsmanship Museum in Vista, CA. A stainless steel version of Paul Knapps Bentley BR2 is also on display along with many other engines and outstanding examples of miniature craftsmanship of all kinds. Visit the museum on-line at www.craftsmanshipmuseum.com. A tour of the Craftsmanship Museum can be seen on YouTube by doing a search for Craftsmanship Museum.

Congratulations to Robert Cooper for his beautiful 12-foot wingspan "Gigantic" and a successful flight. Special thanks go to Ray Williams for his expertise and assistance, Mac Hodges for his experience at the controls, Dale Cavin (Contest Director) for clearing the air for the Gigantic, and Glenn Torrance and Robert Warner who helped prepare the aircraft for its maiden flight. Video documentation by Paul Knapp.

NOTE: The first part of the video shows the initial runup of the engine. The actual takeoff starts at about the 6:30 point of the video. Except for one high speed pass, most of the flight was flown at 1/2 throttle. The 12.5 pound engine has plenty of power.

Category:

Autos & Vehicles

Tags:

• Rotary
• Bentley
• BR2
• model airplane
• engine

[caterpillarnut]

Beautiful! What are you guys burning?

[craiglibuse]

@caterpillarnut , Paul Knapp says he burns the lowest octane fuel on the market, namely Unleaded Gas. It burns faster than the high test stuff and the engine just loves it. He recommends it to all his engine builder friends. He ran out once and borrowed some high octane aviation gas and the engine ran terribly. He bought some unleaded and it ran great again.

The Bentley uses straight unleaded- no oil added. The engine has a pressure lube (total loss) oil system and uses straight Castor Oil.

[Alisterwolf66]

How about the ignition and carburetion? Does the model work like the genuine thing (blip switch, fractional ignition, mixture control, etc)?

Absolutely stunning craftsmanship! You have my utmost respect for this.

[craiglibuse]

@Alisterwolf66 The model engine works just like the full-size version using a simple block-tube carburetor eliminating the need for a blip switch. These simple carburetors required constant attention to minor fuel adjustments. During landings the pilot had his hands full trying to adjust fuel and air mixture while throttling down and side-slipping the aircraft to descend. Though most later model rotaries used carburetors many aircraft retained the blip switch for convenience and safety.

[Rikki0]

There is nothing like the chatter of a real rotary engine.

[HENDRIKVENTER1]

this is amazing

[ianny86]

does Paul sell these model? what wold be the cost of one?

[xrayracer1]

that is fantastic!! it even sounds like the full size engine!!

[Granit1973]

Highly authentic flight, awesome

[fleetcaretrucks]

Takes flight @ 6:33

[GGigabiteM]

@Alisterwolf66

Not all rotaries needed blip switches, many later model rotaries had proper carburetion. One notable exception were the Gnome monosoupappe engines, which due to the way they were designed, were impossible to have real carburetors.

[silentknight2112]

all i can say t this video is wow that is truly amazing

[dreamsfgh]

With the added challenge of gyroscopic precession to contend with:) just beautifull, sounds great!

[edcrabb]

Its a Rotary not a radial, so it would have to be fuel injected I think, I don't think it has a carb. Amazing though ..