Project 29er With Twin CY460 Engines!

Discussion in 'Frame Mounted Engines' started by 5-7HEAVEN, Aug 6, 2011.

  1. 5-7HEAVEN

    5-7HEAVEN Active Member

    My Project Scooterguy w/Tanaka 47R engine is done!

    Project 29er started late last year, but a few changes will be made. The same goals of quick acceleration, brute midrange and 40 mph cruising speeds are in mind.

    However, with what I have learned from my center frame engine build, there are issues I'd rather not deal with. Chain jumping and breaking is one. And no matter how well you seal a two-stroke engine, EVERYTHING behind the front of the engine gets covered with a fine mist of engine oil. Besides that, there are interferences with exhaust, Happy Time fuel tank and the rider's legs. Burns on both legs are possible.

    This build will use TWO CY460 4.5 hp engines, rack-mounted w/Staton twin-engine gearbox. The NuVinci hub is already mounted on HD double-walled aluminum rims. "Big Apple" 29" tires should work very well for this street application.

    The frame being used will either be a steel KONA or aluminum DIAMONDBACK 29" unit. I really like the Happy Time 4-liter fuel tank. It holds enough gas to feed a Tanaka 47R for nine days. Five days of feeding two engines will work for me.

    Exhaust and noise might pose issues for the twins. I've run a SBP Happy Time expansion pipe on a center frame-mount 460 engine before. Despite the serious mismatch between exhaust port and SBP pipe, there was a huge power gain, especially at low and midrange. This pipe also made the 460 EXTREMELY quiet, which was surprising. The only downside was that engine oil spray from the muffler was very significant. This shouldn't pose a serious problem if exhaust tubing extends past the rear wheel.

    Since both engines have separate centrifugal clutches, their throttles do not need to be synchronized. Methinks that two hand grip throttles and a set of hydraulic disc brakes will simplify matters on the handlebars.

    Engine clutch springs are my favorite things to break, especially miles from home. Twin engines should eliminate a total breakdown on the road. If one engine craps out, the other will bring me home.

    I can't wait to get this show on the road!:devilish:
    Last edited: Aug 6, 2011

  2. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    Sounds like another wild machine so we need pictures!
  3. 5-7HEAVEN

    5-7HEAVEN Active Member

    This project is moving slowly. I'm a full time student AND a full time State worker and a family man, so time is precious. My commuter MB broke its new cassette; luckily, I had bought two, so repairs were done within 36 hours.

    My friend Rick gave me his broken Staton twin-engine gearbox. I ordered every moving part in the gearbox from Staton today, and will reassemble it myself.

    Looking for that second 460 engine now.:whistling:
  4. darwin

    darwin Well-Known Member

    9 ponies and your hoping to go 40 mph? Your far as throttle would one of those dual pull brake levers work?
  5. 5-7HEAVEN

    5-7HEAVEN Active Member

    LOL, I meant CRUISING at 40mph.Of course, the bike should have enough power to push past 50 mph. I need to be VERY careful not to break the speed limits here.That's a good reason to get pulled over.

    Dual brake levers might work well if each engine controlled separate rear wheels, like on a trike. Separate throttles work better. I had two thumb throttles on my twin-engined cruiser. They worked perfectly.
  6. Mike St

    Mike St Member

    But can you actually finish such a project?
  7. sparky

    sparky Active Member

    If you're really shooting for top speed, I would theorize that one engine is plenty and will provide a better set of trade-offs than two engines.

    Especially with a Nuvinci & Tanaka 47cc on a 29er frame.... you're definitely going to be able to take care of some hills and get your top-speed up there, as well.

    Either way, I can't wait to see how this turns out.

    EDIT: Nuvinci on a 700c rim w/ Big Apple 2.3" tires is my ultimate, long-term goal. I just want to use the lighweight 5:1 reverse gearbox that's only $25 or so on Dax's website and elsewhere. If you can figure out how to mount your 1 engine to this 1 gearbox to your 1 nuvinci 29er wheel... I think you'd be pleasantly surprised at the weight, speed, & acceleration. Only problem is that the gearbox doesn't freewheel and the nuvinci's sprocket is fixed... so a freewheel must be added one way or another. I think that solving that dilemma would be more worthwhile than a second engine that will just weigh you down and add more friction. Just my humble opinion, of course...
    Last edited: Sep 11, 2011
  8. sparky

    sparky Active Member

    Hmm.... it appears that you already know of a "freewheel mechanism" that bolts to this gearbox...

    Ahhh... but now that I'm looking at it, it appears you're referring to freewheeling crankshafts.... which wouldn't help out on most rack-mounted setups. But this is in the frame-mounted forum.... and by reading your complaints with frame-mounted setups in the OP... I am officially confused.

  9. 5-7HEAVEN

    5-7HEAVEN Active Member

    This project is more than just slapping on the Staton drivetrain and two engines. Whichever bike I choose will need total engineering and upgrades.

    Weight might need to be added to front end.:detective:
  10. 5-7HEAVEN

    5-7HEAVEN Active Member

    I have two 29" frames. One will be a 29er w/twin 460's; the other will be another Tanaka 47R engine w/center-frame mount, that 5:1 gearbox, shift kit w/8-speed cassette. Both will have wide rims w/Big Apple tires.

    Actually, I'm shooting for acceleration, but speed will come..:detective:

    Here's why I need this: I always claim the lane. I don't share the curb lane, so I don't have to worry about a car edging me into the gutter or curb. I also don't like to worry about last-minute drivers pulling in front of me or stopping in the middle of turning the right corner.

    Here's what I do: In heavy traffic, I'll hop the curb, cross the street and wait for the red light. When the light changes, I hop back onto the main road and blaze down the road at the speed limit. This gives me an excellent headstart from the flow of heavy traffic. When this particular hill(short and steep) is gridlocked, I jump onto the footpath until I get to the hilltop. I'll wait on the roadside until there's a red light or a break in traffic. Then I'll blow down the road at the speed limit or 5mph over it.

    What I need is power to accelerate and maintain 5mph above the 35mph speed limit, if necessary. There is also a half-mile strip of one-way traffic with a 45mph speed limit. A Morini engine or twin 460's would provide enough push to consider using this route to work. Any other engine setup that I have considered is too weak to try this fast route. I'm not considering Morini because of its troublesome clutch. The 460 also has an unreliable clutch. However, using TWO 460's would solve the problem of breaking down 20 miles from home. If one engine quits, I can get home on the other engine.

    The Tanaka engine on my 26" Diamondback bike is very reliable, with a shift kit and 8-speed cassette. I've also had a 460 engine on this bike with friction drive, then with the shift kit. Between high horsepower and a steep learning curve, I've broken many 8-speed chains with the 460 and 47R engines. In fact, I bought a NuVinci hub, figuring that the cassette and 8-speed chain could never survive the abuse of a powerful engine. It has, so now I have a new NV hub to stick into my next MB project.

    Actually, this 460 twin-engine idea was my friend Rick's idea. Sadly, he blew the Staton gearbox, gave it to me, and is now working in the Middle East. Now it's my turn to develop this crazy project.:jester:

    Many members have used Morini engines; no one has ever tried twin 460's.:devilish:
    Last edited: Sep 11, 2011
  11. lowracer

    lowracer Member

    I'm looking forward to seeing this project come to fruition as I've enjoyed your previous work...
  12. 5-7HEAVEN

    5-7HEAVEN Active Member

    Hey thanks a lot, man.

    I can't believe the local bike shop has been sitting on my new frame for 11 months!
  13. sparky

    sparky Active Member

    If the clutch is the only beef you have the with the GP460, then get the better clutch springs that you'll HAVE to get a month or so down the road. Just replace the springs up front!! I'm just not a fan of the twin motor idea, but to each their own.

    :bowdown: 29'er + 47R + shift kit + Nuvinci hub = "the ultimate"

    I guarantee you that such a build would beat any Thing else. PERIOD.

    In terms of acceleration [up hills], top speed, weight, balance, etc.

    It seems that the shift kit is the only way for the Nuvinci to freewheel without the Staton gearbox. Staton gearbox is just too heavy for me.

    But yea... it sounds like you've already got it all set up, you just haven't put the wheel on the bike. Try that out for me and let me know how awesome it is!!
  14. lowracer

    lowracer Member

    I have often thought about installing a 2nd engine on my bike (I even went as far as buying some specialty connectors to attach a rear rack to the axle) but I never went through with it. Having recently changed from a heavy Lifan 98cc 2.5 to a light Pocketbike engine I can see that the biggest obstacle is weight. Keeping things simple (my philosophy) has kept me from tackling this project but I still think it would be awesome having that much extra power throughout the rpm range I ride within, even for just a little while as an experiment. The bike I ride now has more than enough power for speedy acceleration & speeds up to ~50mph+, but it sure would be fun pulling both throttles...
    Cant wait to see how your project come out....DragonLady was quite the machine...(great vid)
  15. 5-7HEAVEN

    5-7HEAVEN Active Member

    I have tried various aftermarket clutch springs on the 460 engine. I also replaced the its clutch with a velvet-smooth pocketbike clutch.

    They all failed within a few months.

    Granted, it could've been because of the steep learning curve of using this engine. It could've also have been because I expected the engine to pull away from a standing start. It could've been because of using a 32t first gear, instead of a 34t. This engine's clutch springs failed with friction drive AND shift kit.

    On my last clutch spring failure in its center-mount position and shift kit, I decided to pull the 460, replacing it with a new Tanaka 47R engine. It was a good choice. Even though the 47R might have less power, it gets the job done on my commute. In its center-mount position, its expansion pipe wraps perfectly around the top tube. In eight months running, the Tanaka has not experienced any clutch issues or ANY problems whatsoever. The 47R is considered a loud engine, but it's much quieter with a pipe. It also gets about 80mpg, accelerates very well and cruises easily @ 35mph. If pushed, it will maintain 40mph and peak past 45mph. AND, it is a very dependable engine.

    :detective: IMO, Tanaka 47R is the BEST high-performance engine for use with a shift kit and cassette gearing. It would work well with a 26" OR a 29er. Cassette gears should be a better choice than the NV hub. They are more than 10 times cheaper, MUCH lighter and easy to replace. In a center-mount position, the bike is better balanced than a rear-mount setup, ESPECIALLY if fitted w/a cassette. With an NV hub, it becomes tail-heavy, I would imagine.

    Staton gearbox isn't really that heavy. Engine power nullifies extra weight. My Trek w/Mits TLE 143 engine, Staton box and NV hub weighs 62lbs., the same as my Diamondback bike w/center-mount Tanaka engine. The Trek's front end is EXTREMELY light; the Diamondback is almost perfectly balanced w/its 29" ROCKSHOX fork. Methinks that extra weight needs to be added to the Trek's front end. It seems too easy to jerk the front end off the ground and flip over backwards.:ack2:

    As mentioned before, I have two 29er frames. One will run twin 460's, just for the heck of it. The other will run a spare 47R with shift kit and 11t-34t cassette. for the 29er w/shift kit, I'm trying to get a vendor to fab an 80-tooth 8mm chainring sprocket. This would lower first gear from 37.09:1 to 41.2:1 to compensate for the taller 29" tires. Eighth gear would be more usable @ 13.33:1, instead of 12:1.

    I wish I could center-mount the Staton twin-engine gearbox. The bike would be better balanced than a rear-engine setup. With too much weight on the tail end, I just might HAVE to center-mount the twin-460's.
    Last edited: Sep 17, 2011
  16. 5-7HEAVEN

    5-7HEAVEN Active Member

    Yeah, I miss the Dragon Lady. That bike could run WOT for 10 miles in 87* weather without missing a beat. It was a heavyweight @ 105 lbs, compared to my faster 62lb Diamondback. If I had a garage, I would've kept that twin-engined bike. Friction drive ate tires regularly; I would've replaced both drives w/BMP chain drive.

    In contrast, I expect Project 29er w/twin 460's to weigh around 70lbs.

    Yes, it was a BLAST! pulling two throttles! The engines DRONED instead of screamed. There was MUCH less stress on each engine, because they were sharing the load.:detective:

    I expect the same to happen with twin 460's.:tt1:
  17. Mike St

    Mike St Member

    My reaction, excellence in engineering is simplicity. Rather than two motors, two drives, one more powerful engine makes sense in terms of complexity and weight. Keep your designs as simple as possible.
  18. 5-7HEAVEN

    5-7HEAVEN Active Member

    Simplicity is finding a powerful DEPENDABLE engine with a RELIABLE 76mm clutch. An early-model Staton gearbox or his twin-engine box do NOT have external access to the engine(s)' motor mount bolts. To simply replace a clutch spring would require considerable effort, not something to be tackled on the roadside. The gearbox would have to be removed and the case split. With the Scooterguy setup, simply remove four engine mounting bolts, carb connection and killswitch. The engine then falls away from the bike.

    The 460 engine is an affordable, powerful engine. However, its clutch leaves something to be desired. If I could adapt a Tanaka 47R clutch to it, I'd consider using it as a single engine bolted onto a Staton box.

    Since I don't consider it a reliable engine, a spare engine would be insurance of roadside failure.

    Besides, I've got the twin-engine gearbox, so I might as well use it.

    Also, where else will you find 8.5hp for $500, which will bolt onto the 76mm drive systems?

    FWIW, I ran a twin-Mitsubishi engine/friction drive setup on my Raleigh cruiser. It was simple and powerful, but a heavyweight at 105lbs.:ack2:
  19. 5-7HEAVEN

    5-7HEAVEN Active Member

    Staton gearbox uses two motors and a single chain drive.:detective:

    Twin-engine box weighs a few ounces more than his regular chain-drive. The extra 460 engine weighs less than seven pounds. Total weight of both engine is 13lbs. Honda GX50 has the size/weight of two 460engines. :detective:
  20. Mike St

    Mike St Member

    Well good luck with the two engine concept, but I don't think two engines would make it in any market, except for an aircaft..