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Bentley BR2 Rotary engine
Posted: Sat Sep 13, 2025 8:16 pm
by MikeN
As requested; here are some pictures of a Bently aero engine I started making over 20 years ago but got distracted and kept building other things. I have just pulled all the bits out for a look and plan on continuing it now ive finished my BT5.
Often, the building of models can be difficult and sometimes tedious. This engine manages to combine both. Its Bl*/%y difficult AND tedious. There is 9 or 18 of everything to make!
However I think ive made over 90%. Just got to make 18 volute valves springs, 18 pushrods, 18 HT leads and insulators, etc etc.
Re: Bentley BR2 Rotary engine
Posted: Sat Sep 13, 2025 8:19 pm
by MikeN
Been working on finishing the pistons and piston rings the last few days
Piston rings being finished to size
Re: Bentley BR2 Rotary engine
Posted: Sat Sep 13, 2025 8:25 pm
by Stormbringer
Thats quite a project your doing
Re: Bentley BR2 Rotary engine
Posted: Sat Sep 13, 2025 8:28 pm
by MikeN
The BR2 was fitted to the Sopwith Pup aircraft. It reputedly killed more pilots than enemy action. Being a rotary radial engine, the torque reaction of the spinning mass make the aircraft roll the opposite direction when the wheels leave the ground which catches the unwary or novice pilot with disastrous results.
Re: Bentley BR2 Rotary engine
Posted: Sat Sep 13, 2025 8:59 pm
by Stormbringer
Yeh like the Griffon engined Spitfire if a novice pilot coming into land was a bit low and blipped the throttle the plane rolled onto its back with the torque
Re: Bentley BR2 Rotary engine
Posted: Sat Sep 13, 2025 9:55 pm
by ColemanCollector
Beauty! Are you going to build a scale Sopwith Snipe to go around it?
One of the late war rotaries to carry over into post-war use before radials became the way to go.
Mike.
Re: Bentley BR2 Rotary engine
Posted: Sat Sep 13, 2025 9:57 pm
by MikeN
Stormbringer wrote: ↑Sat Sep 13, 2025 8:59 pm
Yeh like the Griffon engined Spitfire if a novice pilot coming into land was a bit low and blipped the throttle the plane rolled onto its back with the torque
I think it might have been even worse with the Seafire . The Griffon engine rotates the opposite direction to the Merlin. When the later Griffon powered aircraft came in to service, it was often the older more experienced pilots who got caught out having flown years on Merlin types. I suspect rolling and crashing off the front end of a carrier going full speed is even less forgiving than doing a similar thing on a grass runway.
This is described in the excellent book "They gave me a Seafire" by Cmdr Mike Crossley.
Re: Bentley BR2 Rotary engine
Posted: Sat Sep 13, 2025 10:29 pm
by Herr Dr. Professor
O.K. I'll ask. Your engine looks as if it will actually run. Right? Not right?
Re: Bentley BR2 Rotary engine
Posted: Sat Sep 13, 2025 10:54 pm
by MikeN
Herr Dr. Professor wrote: ↑Sat Sep 13, 2025 10:29 pm
O.K. I'll ask. Your engine looks as if it will actually run. Right? Not right?
Yes!....... I hope.
Re: Bentley BR2 Rotary engine
Posted: Sat Sep 13, 2025 10:59 pm
by MikeN
MikeN wrote: ↑Sat Sep 13, 2025 10:54 pm
Herr Dr. Professor wrote: ↑Sat Sep 13, 2025 10:29 pm
O.K. I'll ask. Your engine looks as if it will actually run. Right? Not right?
Yes!....... I hope.
If you.look online you will see others have built them. Full drawings are in the book shown in the book in my picture above.