DYEATON Posted August 24, 2023 Share Posted August 24, 2023 What are some good water cooled engines to replace the rotax 503, that are not much heavier? Link to comment Share on other sites More sharing options...
Area-51 Posted August 25, 2023 Share Posted August 25, 2023 (edited) Edited August 25, 2023 by Area-51 1 Link to comment Share on other sites More sharing options...
Thruster88 Posted August 25, 2023 Share Posted August 25, 2023 Would love to get my hands on an 850 etec for the thruster, would be epic. 1 Link to comment Share on other sites More sharing options...
Thruster88 Posted August 25, 2023 Share Posted August 25, 2023 15 hours ago, DYEATON said: What are some good water cooled engines to replace the rotax 503, that are not much heavier? The only one out there right now is a used Rotax 582, most users of Rotax 503 in Australia have made the switch over the last 20 years. This thruster which flew at Oshkosh in 1988, started life with a Rotax 503. 1 Link to comment Share on other sites More sharing options...
facthunter Posted August 25, 2023 Share Posted August 25, 2023 2.5 times the current Power would be a change, but since they don't overspeed in a near-vertical dive, getting off the ground fast might be the most noticeable difference. It would be a change reducing the power so much once you levelled out. Nev 1 Link to comment Share on other sites More sharing options...
Litespeed Posted August 25, 2023 Share Posted August 25, 2023 I think you fellas have the wrong airframe in mind, but all's fair when "in thrust we trust". My devious mind immediately jumps to a new FAI 300 kg record breaker.. High G, high Vne to take full advantage of such a powerful light engine. The Arnold Ar5 did 213mph on 65hp what could a 165hp more advanced design do?🤔 I am confident such a beast could blow the record easily. Anyone for 280mph? Naughty thoughts I know, but damn that would be awesome. Link to comment Share on other sites More sharing options...
facthunter Posted August 25, 2023 Share Posted August 25, 2023 You will get a rough ride in most of those speed Machines. Nev Link to comment Share on other sites More sharing options...
SAJ Posted August 25, 2023 Share Posted August 25, 2023 Even the 600 E-TEC would make my Thruster exciting. Betcha they wouldn't be cheap. 1 Link to comment Share on other sites More sharing options...
Litespeed Posted August 25, 2023 Share Posted August 25, 2023 Yes , it's a optimised for speed and light. It really would be a superbike weight and faster than a hypercar in the air. It is a not meant for a luxury ride as a record breaker but could be throttled back for a smoother ride as a sport flyer. It would be a burn holes through the sky machine. A more sane version at 240 mph would still be awesome 😎. No it won't be a low speed pussycat but that's the trade-off. As a mini rocketship. No need to chase records, then build to 350 kg or more depending on range required. You travel a lot of ground at those speeds. Why build a jet sonex when you could blow it away with a stroker far cheaper. 1 Link to comment Share on other sites More sharing options...
Litespeed Posted August 25, 2023 Share Posted August 25, 2023 I bet a lot cheaper than a aero version by miles. Naturally a Drifter with even the 125hp would be a real hoot on floats. Link to comment Share on other sites More sharing options...
Thruster88 Posted August 25, 2023 Share Posted August 25, 2023 The Rotax E-tec 2 strokes are used in snowmobiles, they get close to 4 stroke fuel efficiency and electronic control means egt is correct so happy pistons. The is even a turbocharged version with 180 hp. 1 Link to comment Share on other sites More sharing options...
facthunter Posted August 26, 2023 Share Posted August 26, 2023 Vertical twin 2 strokes with the 180 crank have a Lot of balance problems and an 850 is a whopper size for that type of motor, Nev Link to comment Share on other sites More sharing options...
RFguy Posted August 26, 2023 Share Posted August 26, 2023 How about gearbox compatibility ? Link to comment Share on other sites More sharing options...
facthunter Posted August 26, 2023 Share Posted August 26, 2023 Always an issue. Nev Link to comment Share on other sites More sharing options...
Area-51 Posted August 26, 2023 Share Posted August 26, 2023 Its called Experimental Aviation for various reasons; people manufacture solutions to known design challenges Link to comment Share on other sites More sharing options...
facthunter Posted August 26, 2023 Share Posted August 26, 2023 Bu if they continue to re invent the wheel no progress will be achieved. IF it's TOO experimental and you don't learn from the mistakes of others it will be self defeating and self limiting. Aviation got where it is by addressing emergent problems. Nev Link to comment Share on other sites More sharing options...
Area-51 Posted August 26, 2023 Share Posted August 26, 2023 Learning never stops. Boundaries are there for the adventurous foolish and fearless to traverse them. For everyone's safety and well being the only kind of human required to never ever attempt a traverse of a boundary is a bureaucrat. The wheel is not being reinvented, just improved. Link to comment Share on other sites More sharing options...
Thruster88 Posted August 26, 2023 Share Posted August 26, 2023 3 hours ago, RFguy said: How about gearbox compatibility ? Given the higher rpm of the etec compared to a 582 load factor on gearbox is about 1.6 higher than stock 582. C or E box would be ok at reduced tbo, my opinion. Link to comment Share on other sites More sharing options...
facthunter Posted August 26, 2023 Share Posted August 26, 2023 That Motor has no flywheel at all and the reduction gears would cop hell. You need pretty large gears to take that kind of Power continuously ALL gears absorb some power and get hot as a result. Nev Link to comment Share on other sites More sharing options...
Area-51 Posted August 26, 2023 Share Posted August 26, 2023 27 minutes ago, facthunter said: That Motor has no flywheel at all and the reduction gears would cop hell. You need pretty large gears to take that kind of Power continuously ALL gears absorb some power and get hot as a result. Nev Morse Hy-Vo; quiet, less friction, less heat, less weight, less maintenance. No idea why nobody is using it. 1 Link to comment Share on other sites More sharing options...
facthunter Posted August 26, 2023 Share Posted August 26, 2023 Has been used with some motorbikes and transfer cases and can be pretty heavy for high torque used with . Falcon timing drive . Better than roller chain in some applications... The absence of any flywheel is the problem. Can make motorbikes really nasty to ride. Nev Link to comment Share on other sites More sharing options...
Thruster88 Posted August 26, 2023 Share Posted August 26, 2023 I am sure the E-tec engines have a similar flywheel to the 582, it is needed for smooth operation and the alternator. They are quite substantial. Link to comment Share on other sites More sharing options...
Area-51 Posted August 26, 2023 Share Posted August 26, 2023 The flywheel is the prop assembly same as the 912. Link to comment Share on other sites More sharing options...
facthunter Posted August 26, 2023 Share Posted August 26, 2023 A geared flywheel is a mechanical disaster . All piston engines have torsional harmonics. Nev Link to comment Share on other sites More sharing options...
Thruster88 Posted August 26, 2023 Share Posted August 26, 2023 1 hour ago, facthunter said: A geared flywheel is a mechanical disaster . All piston engines have torsional harmonics. Nev The flywheel on 900 series and all the Rotax 2 strokes is at the other end from the gearbox. Proven over many decades. 2 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now