The Kneeslider

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CR700P 700cc Rotary Racer From Crighton Racing

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CR700P twin rotor racer from Crighton Racing
CR700P twin rotor racer from Crighton Racing

Rotary engines in motorcycles have always been a rare sight, in racers, rarer still, but it looks like Brian Crighton has built one and he wants to get on the track with it. The CR700P, is a twin rotor 700cc racer with a very respectable 200 horsepower and 100 foot pounds of torque and it weighs in at only 300 pounds! That should be enough to get a rider’s attention.

CR700P twin rotor racer from Crighton Racing
CR700P twin rotor racer from Crighton Racing

Brian began working on rotary engines at Norton back in the late 80s and played a very large part in their racing program with the John Player Specials and, after resigning from Norton, built a brand new rotary racer campaigned successfully by the Crighton Norton team in the early 90s.

Brian has come back with a totally new bike, the CR700P. The Rotron 200hp twin rotor uses a “pressurized gas cooling system,” I’m not exactly sure how that works, but they attribute the engine’s capability of sustained high rpm operation to it, so it must work pretty well.

CR700P twin rotor racer from Crighton Racing
CR700P twin rotor racer from Crighton Racing

I didn’t see any photos without the fairings, so what the engine looks like in the frame is a bit of a mystery, but I’m sure those will turn up soon enough. Rotary engines seem to be powerful little beasts and, though rotor seals have been a problem over the years, you have to think they’ve got that pretty well sorted by now. If they could get emissions under control, current power levels would make for an interesting street bike and might give some inline 4s a bit of a scare.

The bike looks good and the rider in the video seems extremely impressed with its power, now all it needs is a chance to prove itself on the track. I’m not sure what class or race series it’s aimed at, rotaries seem to have a difficult time fitting into the class structure against the standard internal combustion engines, so we’ll see where they land. It could make for an interesting competition. I wish them the very best of luck.

Thanks for the tip, Bob!

Link: Crighton Racing

Link: Crighton Racing on Facebook

Comments

  1. I guess I date myself, but I remember the Hercules rotary that became the Norton rotary, and the the JPS racers that would puke flame out at every downshift. This could be an awesome ride if it is affordable. Best of luck to all!

    Mark L.

  5. The big problem (though not insurmountable) is that rotaries are basically two-strokes. MPG will be what you’d expect out of a 200hp two-stroke, and emissions will be a challenge. Direct gasoline injection may do the trick…though the automakers have spent a lot of money on Orbital and there’s been a distinct absence of two-strokes in cars. So far.

    • Agreed, however add to this the fact that all those engines on the site listed above by John run on jet fuel. Judging by the smoke emitted by that exhaust while staging, I’d say that one probably runs on the same stuff. (Probably smells great though!)

    • Actually the Wankel is fundamentally a 4 stroke (or technically 4 cycle) engine. It has 4 discrete phases just like your favorite modern road bike. Intake compression power and exhaust. MPG would be what you should expect out of any 4 stroke that can match the performance figures of the engine. A mazda 13B detuned to match the output of your typical 1300cc road car will easily knock out 40+ mpg. In fact built to match piston engines in size and MPG a rotary will typically still deliver more performance than the boinger will. The rotaries reputation for consumption comes mainly from its production variants being sold as performance engines. Show me a 1.3L piston engine in a 3100 pound car that makes 230 hp and 160 tq with a broad torque curve and dead smooth idle that gets better than 25 mpg. Even the craziest superbikes like the Busa don’t deliver the numbers the dose, especialy the torque.

  6. Looks like Saturn V Rocket power. Has that GREAT rotary sound as well. Very Sweet!

  7. that’s not just a rider, that’s james “jammie” witham! A legend that still comments on BSB, WSBK and other motorcycle sports for eurosport. Look on youtube after his race on a rgv 250 against fogarty on a honda vfr 400 😉

    as for the bike, I love rotaries and I’m thinking of building one, this one looks suspiciously much like the norton nrv…

  9. I imagine the stated engine capacity is only considering one of each of the rotors three chambers. The engine is more likely 2100cc. Still, Wankels are cool.

    This one might be cool by compressing CO2 (R744) through a gas/water heat exchanger. Basically, it’s refrigerated. Cool indeed.

    -todd

  10. I am glad to see a rotary motorcycle still being thought of. The power to weight ratio is phenomenal! The rotron rotary engine is greatly appreciated by those who actually know how to measure the capacity!!

  13. This is super cool.

    One of the advantages of the rotary for racing or sustained high rpm operation is efficiency. They run best when operating at higher rotations than a conventional piston engine. I think that’s one of the reasons the 787b racer was so successful. Insane power, reliability at that power level, and the ability to sustain that abuse for the whole race.

    Modern rotaries like the renesis still suffer from oddball issues. The renesis has the exhaust ports on the side rather than the face of the motor in an effort to reduce emissions. This lead to flooding issues.

  14. Great to see the rotary revival. I have been reading elsewhere that Crighton has been building this bike. It looks impressive and given his experience with the Norton racers, if anyone can make a rotary bike work well, it’s him.

    The Norton rotary racebikes were notoriously hard to control. They went from half to full power with very little throttle movement. Thehandling was also suspect at first, with some later versions going back to twin shocks at the rear. But I expect Crighton has found a fway through all this to make something more ridable.

    The Norton Commanders made good road bikes. I’ve seen one with 80,000 plus miles on the clock that belongs to a guy who lived near me and they’re supposed to be able to top that easily as well.

    • wandering Vintage Days at Mid-Ohio a few years ago and saw a Norton Commander Rotary in Full Police set up, The owner told me He just replaced the apex seals for the first time with nearly 380,000 miles on the clock! Talk about longevity from maintenance.

  15. Todd, you are using the insurnace company method to figure the engine size. I own a 75 Hercules with the Sachs/Wankel 250cc rotary engine. One of the things that led to the demise of these bikes was some insurance companys insistence that a 27hp 250cc Wankel engine was in fact a 750cc. Since the bike’s were expensive to begin with then add in increased insurance rates, they just weren’t affordable. Glad to see these guys experimenting once again with the rotary concept.

    • That’s also how the SAE determines engine capacity for Wankels (SAE J1220) which is likely why the insurance agencies use it.

      -todd

  16. Great news!! I thought the Norton Wankel project died,since nORTON prefers making RSV4 TT racer caferacercommandos and domiracerreplicas……VIVA CRIGHTON!!!!!And thanks again for the good news,Kneeslider.

  17. I enjoyed the hell out of my first generation RX7 (an ’84, last year with carburetors!). Even back then, the apex seal issue was not as huge a deal as some folks made out. The two caveats were: Make sure it never runs low on oil, and make sure it never runs low on coolant. With the CR700P being a race-only machine, is there a time limit on the cooling system, like a total loss ignition system? Whatever the details, I love this.

    • Crighton made the bike in the above link, I like the bit about the continuously variable over 120mm intake!

  19. I love it and about time someone has built a great rotary bike I want one great bike and smooth not like the v 4’s and v 2 engines love it love it.

    Cheers Leon

  20. Web-Search for recent patents from “Garside” and “SPARC” in regards to a closed loop oil / air cooling system that has a intercooler to extract the heat for the Rotor(s) This is what this engine maybe employing….

  21. Exhaust temperature is the weakness of the wankel and the reason for their poor bsfc.
    The expansion ratio must be low leading to high exhaust temperatures.