Are two-strokes worth a second look?

Discussion in '2-Stroke Aircaft Engines' started by cluttonfred, Feb 9, 2018.

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  1. Mar 15, 2018 #81

    Aviator168

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  2. Mar 15, 2018 #82

    Armilite

    Armilite

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    I thought they did a long time ago, I don't know if they are still in business, haven't heard much about them for years now. We have lost so many of these Engine companies with the world population almost doubling since 1971.
     
  3. Mar 16, 2018 #83

    BBerson

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    I don't know, he said the crankshaft was double rpm. And all cylinders firing simultaneously is strong torque pulses to the prop.
     
  4. Mar 16, 2018 #84

    BBerson

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    Armilite, look up Chotia 460, the only purpose built direct drive ultralight 2-stroke, I can think of. McCullough and Nelson were direct drive four cylinder.
     
  5. Mar 16, 2018 #85

    TFF

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    Armilite, you believe in two strokes and are from a place where they were successful. The rest of the US is not like that. Yes ULs are heavy into 2 strokes. It's one of the reasons you don't see many ULs about. It does not matter why somethings get bad names, but it is almost impossible to bring them back once it happens. The cheap Chinese RC engines killed that segment of the hobby making electric great for all the fumble fingers who could not get them to run. There wil always proponents of two strokes. Their day is done for popularity. For the ones who want to keep using them, sounds like there is some deals to be had as long as there are parts. I'm not against two strokes. I have just got a 1972 Yamaha 100 and only fly glow RC planes. All that means is I am ok being on the back side of the curve.
     
  6. Mar 16, 2018 #86

    Armilite

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    I see this Info about it, used on a WeedHopper: Chotia 460 engine which develops 25 horsepower and weighs only 32 pounds.
    http://all-aero.com/index.php/contactus/11653-weedhopper-jc-26-a-gypsy

    Compression Ratio of 10:1
    Wingspan, 32 ft
    Wing area, 144 sq.ft
    Aspect ratio, 7.1
    Overall length, 18.5 ft
    Empty weight, 165 lb
    Usable payload (include fuel), 250 lb
    Wing loading, 2.31 lbs/sq.ft
    L/D power-off glide ratio: 16.1
    VNE: 65 kt / 75 mph / 120 kmh
    Cruise speed (85% power), 60 mph (redline)
    Stall: 22 kt / 25 mph / 41 kmh
    Ap-proach speed, 30mph
    Flair speed, 22 mph
    Liftoff speed, 25 mph
    Take-off distance (50ft obstacle): 100 ft / 30 m
    Landing distance (50ft obstacle): 35 ft / 11 m
    Rate of climb, 400-600 fpm
    Fuel capacity, 2.5 Usgal
    Range at cruise, 60 mi
    Engine displacement, 456cc
    Rated HP, 30 hp
    Static thrust 140-150 lb
    Cockpit width, 24 in
    LSA: yes

    I didn't see it's Bore & Stroke they used to get that 456cc. I see a 25hp rating and a 30hp rating, but not at what rpms there refering to.

    To comapre, a 400.5cc Simonini Victor 1 Super with 9.5cr, turning 6500rpms, with a Tuned Pipe makes 54hp today.

    From an Article:
    The biggest single improvement to the C model came about when Weedhopper switched from the 25 horsepower Chotia power plant to a Rotax 277 engine that produced 28 horsepower. http://ulav8r.com/weedhopper_jc-24C.htm

    This manual says 3600rpms.
    https://www.scribd.com/document/30401390/Chotia-460-NewManual-1

    IF, Designed and Built right today using a Tuned Pipe and 11.5cr:
    456cc at 90% efficient at 3000rpms = 29hp
    456cc at 90% efficient at 3500rpms = 34hp
    456cc at 90% efficient at 3600rpms = 35hp
    456cc at 90% efficient at 4000rpms = 39hp
    456cc at 90% efficient at 4500rpms = 43hp
    456cc at 90% efficient at 5000rpms = 48hp
    456cc at 90% efficient at 5500rpms = 53hp
    456cc at 90% efficient at 6000rpms = 58hp
    456cc at 90% efficient at 6500rpms = 63hp
     
  7. Mar 16, 2018 #87

    Armilite

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    ============================================================

    While the World is a very Big Place, for about $200 you can get about any 2 Stroke Shipped to your door. With eBay, Craigslist, www.Searchtempset.com and Google you can Shop the World for about any Engine you want, or Parts for them. I haven't been into RC Aircraft for 50+ years, since the COX .049 in a PT-Trainer, and a few others I had, all fly by String. While I know some RC stuff has gotten Bigger, the 80cc to 100cc Engines should handle them. Some people put as much Money into their RC stuff today, that they could be building and Flying an Ultralight. There is still Plans out there, and many used Planes if you look. Even the Heavy So called Ultralights can be put on a Diet to make Part 103. You do have the Option to go Sport Pilot with them also. The reason you don't see many Ultralights out today, is these Companies thought they could make Big Bucks selling Light Sport Aircraft and raised their Prices almost over night, and People don't have as much spendable Income today, with most Big Ticket items Doubling to Trippling in the last 15 years, Cars, Trucks, Boats, Bikes, Guns, Snowmobiles, Homes, Food, ATV's, etc. Light Sport didn't have the infastructure setup for Light Sport Training, still doesn't in many places.

    My New 1990 Suburban $18,000, my New 2001 Suburban $38,000, a New 2016 Suburban base line was $64,000, the one I wanted was $72,000. Peoples wages haven't kept up. When Light Sport came about, 85% of these Old Ultralights weren't in compliance with Part 103 Rules even though they had been flown like that for 25+ years. They should have had a Exsperimental License way back then, but the FAA didn't push it, Light Sport gave them an Out. Last time I checked an Aerolight 103 and the Phienox 103 were both around $16,000, New. You can Buy most Plans for under $100 and build it yourself for Half there cost. Most Part 103 Ultralights don't really need more than 35hp, so you have many different Engines to pick from that can make that. A Good used Ultralight or Heavy Ultralight can be bought for under $4000 today. I paid $5000 for my T-Bird I with a 503UL, Full Enclosure, Heater, Tri-Gear, 12 gallon Tank, which doesn't comply with Part 103, but could be put on a diet to comply. I don't know if Indy Aircraft the last manufacture of the T-Bird, if their still in Business. A Tail Dragger Airframe with a Hirth (28hp), Rotax 277 (26hp), Simonini Victor 1 (44hp), should make Part 103.

    Some of these new Electric Motors for Ultralights/Kitplanes are awesome, but it will never go anywhere account of there High Cost, most Ultralight Planes start out at $35,000+ and the Batterys are only good for about 7-8 years and their Replcement is very Exspensive $7000+. If people aren't buying $16,000 Ultralights, they sure aren't going to buy $35,000 Ultralights.

    The main reason most of these Companies are not Selling their Ultralights/KitPlanes is they practice very POOR MARKETING. Most don't have a Business with a Show Room, some don't even have a Sign, their Building is missing Address Numbers, Don't Answer the Phone M-F 8am-5pm, or have an Answering machine, don't return e-mails, don't have a Web Page, or don't Register it with the main Search Engines like Google, don't have a Booth at Oshkosh, Sun & Fun, or even local Air Shows, don't have a Booth at other Large Events where many 1000's of People attend. Ever see any Ultralight/Kitplane manufacture have a Booth at the State Fair, County Fair? Believe me I have visited many Kit Car, Kit Plane Dealers/Manufactures over the years.

    Now I just checked my e-mail to give you an example, I e-mailed Culver Props last Thursday, 7 days ago now, still haven't got a reply about a Prop. I drove down there last Sat on my way to Branson, the Building had No Sign, No Showroom, the Building was missing one Number on the Address, called, no one answered the phone, no answering machine, knocked on the door, no answer, wasn't sure at first it was even the right Business Building, so I drove down the road to check, on the way back by a couple of guys were standing outside by a car and I pulled over, and one guy said ya this is Valley Engineering and Culver Props. Now these Two Building are right next to the Interstate where probably 80,000 Cars and Trucks a day go by, so a Good Sign on the Building is Free Advertizing. He did proceed to tell me the gal who ran the office went to Flordia for the weekend, he thought she was leaving after 5pm, and he did answer some of my questions, and he did show me the Prop Building and the one Plane they were building in the other shop building. It looked real nice, the Back Yard Flyer, a piece of Jewelry, all welded Aluminum construction, but needs to be simplfied for Production, they only make (1) a year he said. I have had that same exsperiance at some other Dealer/Manufactures I have visited. Sadly, many Companies in the USA have lost the meaning of Service, and Quality and Ethic's.

    Of just the popluar Ultralights, Challenger, T-Bird, Kolbs, Weed Hopper, Lazair, etc., there was probably 35,000+ built in the last 40 years.

    You say you bought a Yamaha 100cc, what HP@rpms and what did it Cost?
     
  8. Mar 16, 2018 #88

    Armilite

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    Aaen - VINTAGE 292 Yamaha RACE PIPES.
    We have two pipes available for the popular 292 Yamaha single engine. The full race pipe is developed for modified Oval racing and delivers 70 HP at 9000 RPM with Full Race Porting, Reed Valve intake and a larger Carb. We also have a milder pipe that is turned for 7500 RPM and delivers 50-55 HP depending on Cylinder Porting. This pipe is very popular in One Lunger Sno Cross Enduro Races or for Vintage Trail Riding and Restorations.

    Just about every Snowmobile Engine Company made a 292 Single, that was a popular Racing Class.

    1973 Yamaha SR292 Vintage Racer. Free Air Version.
     

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    Last edited: Mar 16, 2018
  9. Mar 16, 2018 #89

    Turd Ferguson

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    The original sales literature for the Chotia 460 advertised 18.5 hp at 3500 rpm.


    Type: Single Cylinder, air-cooled, direct drive, two stroke.

    Cylinder:
    Bore: 88.00 mm (3.47 in.)
    Stroke: 75.00 mm (2.95 in.)
    Swept volume: 456 cc (27.85 cu in.)
    Schnurle-port design.
    4 bolt exhaust flange.

    Connecting Rod: Machined bar stock.
    Needle bearings at both ends.

    Crankshaft: Three ball bearings.
    Reversible rotation.
    Direct drive.

    Induction: Impulse fuel pump.
    Bowl-type carburetor.
    Fuel-Oil ratio 50:1
     
  10. Mar 16, 2018 #90

    cheapracer

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    3 moving parts refers to a crank, rod and piston of course. My point was relevant to the "simple engine" comment, but no one wants them.



    Nonsense. Use the Internet, try that new program called Google.



    Oh so now it's a "racing bike" specifically? Go back and read your own post, it wasn't a racing bike before, but hey, it's still wrong anyway.

    ..and you're the one proffering info, the onus is on you to provide proof.

    2 strokes for the last 30 years have had a wider powerspread than an equivalent capacity 4 stroke. Fact, period.

    For the benefit of those genuinely interested, here's a video, one of thousands available, showing the incredible low speed tractability of a modern 2 stroke, in this case a "racing" 2 stroke producing over 200 hp per liter, that's like a Rotax 912 having 500HP.

    Watch the wide power spread and smooth power delivery.

    [video=youtube;RkH58xXrlzg]https://www.youtube.com/watch?v=RkH58xXrlzg[/video]
     
    Last edited by a moderator: Mar 20, 2019
  11. Mar 16, 2018 #91

    proppastie

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    My back hurts just watching.
     
  12. Mar 17, 2018 #92

    homebuilderfan

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    Skilled guys using their bike in a skilled way.
    You are right: two strokes can perform well from low to high rpm. But people don't believe this fact because the companies are pushing different engines.
    I had a Montesa Cota 304 (time ago...); it was astonishing to enjoy the robust torque pulling me up the hills using very little accelerator; it was in 1987. Think about it, 4 strokes guys.
     
    Last edited by a moderator: Mar 20, 2019
  13. Jul 27, 2018 #93

    wanttobuild

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    I have always loved the smell of Klotz
     
  14. Jul 27, 2018 #94

    blane.c

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    I think two strokes are fine if you use the old idea of dependability, count on one or more failing at an inopportune time and add as many more as you deem prudent.
     
  15. Jul 27, 2018 #95

    wanttobuild

    wanttobuild

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    The fastest Ultralight in the world, the Pulsar XP, is equipped with the Simonini Victor 2, 110hp
    Aw, it's good to be the King.

    You guys have just about convinced me to go 2 stroke.
     
    Last edited: Jul 27, 2018
  16. Jul 27, 2018 #96

    Turd Ferguson

    Turd Ferguson

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    The fastest 2-stroke powered airplane that I can recall was Nick Jones Lightning Bug, sometimes called the Reflex Lightning Bug which had a claimed all out top speed of 250 mph.
     
  17. Jul 27, 2018 #97

    wanttobuild

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    I looked it up Turd, #20 wing loading! You better be going fast!
    The info I posted was from the Simonini site.
     
  18. Jul 27, 2018 #98

    Turd Ferguson

    Turd Ferguson

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    The claimed stall speed was 62 mph.
     
  19. Jul 28, 2018 #99

    Armilite

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    ==================================================

    First of all, it's Not an Ultralight, and I don't think it qualifies as a Sport Pilot either, probably falls more into Experimental Class!

    The Fastest Legal Part 103 Ultralight is 55knots.

    There was a guy who put a Skidoo 583 97hp in a Quickey(Q1) but never heard what his Top Speed was with it.
    https://www.youtube.com/watch?v=5zwH86MsNXw
     
  20. Jul 28, 2018 #100

    Turd Ferguson

    Turd Ferguson

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    It fits some foreign definitions for ultralight. The Italians are trying to sell their engine so they had to look far and wide to find a classification where they could claim #1 spot, only even then they are not #1, lmao.
     

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