Kitfox Aircraft Stick and Rudder Stein Air Grove Aircraft TCW Technologies Dynon Avionics AeroLED MGL Avionics Leading Edge Airfoils Desser EarthX Batteries Garmin G3X Touch
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 22

Thread: Lycoming vs Continental in a SS 7 ??

  1. #11

    Join Date
    May 2017
    Location
    Modesto CA
    Posts
    185

    Default Re: Lycoming vs Continental in a SS 7 ??

    From my research the Rotex 912 installed weighs about 150lbs, the ContO-200 with accessories weighs about 220lbs, so it appears there's about a 70lbs difference give or take a little.
    As far as fuel burn, again, research shows, basically no difference. Both engines come in about 4.5 gallons per hour........again give or take a little.
    As far as adding weight in the tail for the Cont, seems most compensate by relocating the battery, so no need to add addition lead weight.
    Rotax @ 150 lbs @ 100hp = 1.5php (php= pounds per horsepower)
    Cont @ 220lbs @ 100hp = 2.2 php
    Cont @ 220lbs @ 125hp (high comp pistons, port and polish) 1.76 php
    I plan on 125hp for my O-200 with above mods.
    So in summary, fuel burn difference is minimal and not a factor for me.
    The difference in weight is a consideration, but factor in the hp mod I plan on doing and the difference in pph isn't much, certainly not enough to cut the rate of climb in half and double the take off distance.
    From what I've read, the Rotax has come a long ways as far as reliability and TBO. It's great that many of you love your Rotax's, I have no problem with that.............I just would prefer a Cont or Lyc, and I'm leaning more towards the Cont...............not here to start the great debate which is best............just looking for opinions and experience with the Lyc and Cont powered SS7's
    With that said, I do appreciate everyone's input.
    Brian

  2. #12
    Senior Member
    Join Date
    Jun 2008
    Location
    wales,ny
    Posts
    710

    Default Re: Lycoming vs Continental in a SS 7 ??

    Hi Brian, Nice well educated post on your engine research. The beauty of homebuilding is that you build the airplane you want and are comfortable with. There are some wild exaggerations on some of the previous posts by the Rotax camp. I have a Continental IO-240 in my Series 5 that I have flown happily for 14 years and 800 hours . While it is certainly true that my empty weight is heavy at 950 lbs, the airplane performs great. Climb rate at a mid weight is 1200 fpm , takeoff distance off a grass strip 350' , cruise at 120 mph if I am trying to get somewhere, and if I am flying for the sake of it fuel burn is 4.5 gph (6 gph if trying to get somewhere.) I still have 600 lbs of useful load above my empty weight and I have never been limited with passenger and baggage. (a testament to the kitfox design) So I guess what I am trying to say is listen to all (some with a grain of salt) then do what is right for you. Put this guy in the happy with his heavy continental column. Bruce N199CL

  3. #13
    Administrator DesertFox4's Avatar
    Join Date
    Aug 2008
    Location
    Arizona
    Posts
    3,563

    Default Re: Lycoming vs Continental in a SS 7 ??

    Rotax 912 uls weighs 124.5 lbs.
    Add overload clutch. +. 3.7 lbs. ( not installed in early 912 uls engines now standard)
    Add exhaust. +. 8.8 lbs. ( rarely included in weight comparisons)
    Add airbox. +. 2.8 lbs. ( not installed on majority of 912 uls engines)
    Add engine mount. 4.4 lbs. ( rarely included in manf. engine weights)
    Total =. 144.2 lbs.

    Optional equipment:

    Add external alt. 6.6 lbs. ( rarely needed on a Kitfox)
    Total = 150.8 lbs

    You can see we just hit the previously mentioned weight of 150 lbs. including a few items never listed in engine weights advertised by manufacturers.

    Rotax needs a coolant radiator yet and most times a small oil cooler with related plumbing for both. Obviously the Continental and Lycombings need some of the same above items but not all. Engine fluids are not included in the above weights. Oil content in the Rotax is 3.2 quarts. Coolant not possitive but not much more than a gallon total. Maybe less. Someone will know exact quantities.

    What ever engine you chose , enjoy making your Kitfox the way you envision it. Remember, the factory supports more engine choices than any other kit aircraft in history. The most versitile kit going. Soon the 915 Rotax will be added to that list. Just get a kit and mount your favorite engine to the front and start building lifelong memories.


    DesertFox4
    Admin.
    7 Super Sport
    912 ULS Tri-gear


  4. #14
    Senior Member jiott's Avatar
    Join Date
    Jun 2010
    Location
    Portland, OR
    Posts
    2,960

    Default Re: Lycoming vs Continental in a SS 7 ??

    Yes, I am solidly in the Rotax camp so my biased opinion is: Nearly all this discussion has been about weight and performance, but I don't think nearly enough has been said about many other high tech factors which I consider very important. Gearbox clutch which protects against prop strikes; Water cooling which keeps engine temps steady in optimum range; Modern close tolerance design which uses essentially no oil between changes; Ability to use Mogas at about $1 per gallon savings; No need for carb heat or mixture control; By far the quietest and smoothest engine out there-I fly occasionally in a friends Super Cub with a Lycoming and find the cockpit noise and vibration to be far above my Rotax. Every passenger I ever take comments on the quiet vibration free ride; Very inexpensive automotive type spark plugs (have you priced out Lyc/Cont plugs lately); Electronic ignition comes standard; Built-in generator so no external alternator/belts/pulleys required on most Kitfoxes; Cabin heat with a small heater core-no danger of CO leakage and exhaust heat muffs that crack; probably a few more that I have missed. Many of the above items may tend to be overlooked by someone who is evaluating engine choices.
    Jim Ott
    Portland, OR
    Kitfox SS7 flying
    Rotax 912ULS

  5. #15
    Senior Member
    Join Date
    Jul 2013
    Location
    Highlands Ranch, CO
    Posts
    404

    Default Re: Lycoming vs Continental in a SS 7 ??

    Pounds per hp of the engine alone is of minimal consequence. To be realistic, you need to look at pounds per hp of the total package. Lets say your normal loaded weigh is 1000lbs with a 912uls at 150lbs. The 912uls continuous hp (5500rpm) is 93hp. Matter of fact the Rotax hp chart for the ULS doesn't even reach 100hp at 5800rpm for the 5 min. max. stated.

    1000/93=10.75 lb/hp

    Go to a Cont. at 220 lbs (+70lbs) and 100 hp and you have:
    1070/100=10.7 lb/hp

    Go to a Cont. at 220 lbs (+70lbs) and 125 hp and you have:
    1070/125=8.56 lb/hp

    I'm still in the UL Powwer camp personally!

    YMMV, Greg

  6. #16
    Senior Member jmodguy's Avatar
    Join Date
    Jul 2014
    Location
    Carmel, IN
    Posts
    744

    Default Re: Lycoming vs Continental in a SS 7 ??

    Brian,
    Go with what you know/like/feel comfortable with.
    The Rotax is a good engine but has it's own issues, i.e. carb sync, expensive rubber replacement every 5 yrs, expensive ignition modules etc. Some guys have these figured out and do good preventive maint. Some don't.
    For what its worth you can equip a Lycoming or Conti with electronic ignition and fuel injection (flyefii.com) and have a lot of the same "benefits" of a Rotax. No mixture, uses automotive spark plugs etc etc. The system cost is similar to buying a couple mags plus gears spacers, spark plugs etc and a carb. Yes its a little more complex than mags but the engine will run smoother and start easier. Also there's no 500 hour mag overhaul requirement (not that many do it), The Rotax built in alternator is limited in capacity and expensive to upgrade. You can add an external alt but be prepared to pay heavy just for the mount.
    Are the Lyc/Conti engines heavier than a Rotax? Yup. Easy to work on? yup. Lots of people out there with experience on these engines also.
    As for fuel burn, I personally don't care if my KF has a 6 hour endurance because I can't sit for that long.
    Jeff
    KF 5
    340KF

  7. #17

    Join Date
    May 2017
    Location
    Modesto CA
    Posts
    185

    Default Re: Lycoming vs Continental in a SS 7 ??

    Thanks Jeff, and everyone else for your comments. I use to fly 500 hours in 6 months. but the last few years I flew for fun in my Super Cub, I was averaging about 50 hours a year..........I'm 67 and if I fly 5 yours a year for the next 10 years, I'll be well into my 70's...........so probably won't reach that 500 hr mag overhaul LOL.
    I like simplicity..........that's another reason I like the Cont. I've worked on a lot of O-200 and although I wouldn't attempt an overhaul, I do feel comfortable on doing a lot of various maintenance on them. I've also have several thousand hours sitting behind them, and not one has ever let me down......literally.
    Thanks again, for your input.
    Brian

  8. #18
    Senior Member jmodguy's Avatar
    Join Date
    Jul 2014
    Location
    Carmel, IN
    Posts
    744

    Default Re: Lycoming vs Continental in a SS 7 ??

    Good luck Brian! The O-200 is a solid engine and pretty darn reliable. Nothing wrong with KISS methodology!!
    Jeff
    KF 5
    340KF

  9. #19
    Senior Member PapuaPilot's Avatar
    Join Date
    Nov 2013
    Location
    Nampa, Idaho
    Posts
    1,226

    Default Re: Lycoming vs Continental in a SS 7 ??

    FYI the 500 hour inspection mentioned on the magnetos is not an overhaul, it is just an inspection. I can do a 500 hour inspection on a set of mags in 2-3 hours. The mechanic opens the mag up and and inspects all of the internals. Personally I don't remove the condenser or coil unless there is a good reason. If nothing is bad with the points, condenser, impulse coupling, etc. then the only parts that are replaced are a cotter pin and the woodruff key (which holds on the drive gear or impulse coupling). This inspection can get expensive if there are problems with the impulse couplings, bearings or rotor; or corrosion/pitting of parts. Sometimes the points/condenser need to be replaced, but that isn't too expensive.

    And yes, these engines are very easy to work on.
    Phil Nelson
    A&P-IA, Maintenance Instructor
    KF 5 Outback, Cont. IO-240
    Flying since 2016

  10. #20
    Senior Member
    Join Date
    Nov 2008
    Location
    KDKB (Dekalb, Illinois)
    Posts
    644

    Default Re: Lycoming vs Continental in a SS 7 ??

    I'm with Bruce, I've got an IO-240, I'd say the negatives against it are from
    people who haven't flown one, my airplane flies great, and performs very
    well. Plus it doesn't sound like it's powered by Cox.

    I think the weight argument, is also something that comes from not having
    flown one either. I've never felt my airplane was nose heavy, or didn't feel
    light an nimble. I fly a Super Decathalon some times, and the IO-240 Fox
    makes the Super Decathalon feel like a dump truck

    However, ANY of the mainstream engines are a good choice, it's really a
    matter of money and preference.

    Jeff


    Quote Originally Posted by airlina View Post
    Hi Brian, Nice well educated post on your engine research. The beauty of homebuilding is that you build the airplane you want and are comfortable with. There are some wild exaggerations on some of the previous posts by the Rotax camp. I have a Continental IO-240 in my Series 5 that I have flown happily for 14 years and 800 hours . While it is certainly true that my empty weight is heavy at 950 lbs, the airplane performs great. Climb rate at a mid weight is 1200 fpm , takeoff distance off a grass strip 350' , cruise at 120 mph if I am trying to get somewhere, and if I am flying for the sake of it fuel burn is 4.5 gph (6 gph if trying to get somewhere.) I still have 600 lbs of useful load above my empty weight and I have never been limited with passenger and baggage. (a testament to the kitfox design) So I guess what I am trying to say is listen to all (some with a grain of salt) then do what is right for you. Put this guy in the happy with his heavy continental column. Bruce N199CL

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •