The video is excellent ! As a german guy I appreciate the way of talking, clearly and not too fast and . . . without any music. I have got the Verner 360, which is no longer built. I love this engine, because it sounds like a bigger one and needs less gasoline than others. The cylinders come from the 180cc Scooter Aprilia Scarabeo, mounted together in the opposite layout. I wasn´t happy with the idle speed, which should be 2500 rpms (!) acc. to the manual. At that speed the prop turns nearly 1000 rpm and the airplane needs to being hold by brakes contineously. Landing my SD-1 has been also difficult with that idle power. The reason is less precise caburetor synchronisation which two bowden cables having different plays and different actuation forces. I have changed the carburetor linkage completely and have got now a very precisely working synchronisation. I am glad to having idle speed of 600rpm now with a prop speed of about 250rpm. The engine runs stable and the boxer configuration gives the best possible smooth running at idle. I haven´t flown with the new linkage yet. Speeds of 11.000rpm I should hear before judging about. For my feeling it is not comfortable to fly with an engine which has got such high speeds. Sure, they will be lower at cruise speed but without shiftable gear and normally fixed prop the engine will run about 9.000 rpm partial loaded. Hoping the efficiency is acceptable at this working point.

Thank you. I have been waiting for this one. Well done.

@LetsGoAviate

10 ай бұрын

Thanks!

Thanks for the information. I am new to aviation and videos like this help me out a lot.

Another excellent discussion, keep them coming brother...

My absolute favorite is the Venerable Kawasaki 440 twin cylinder. While it is an older 2 cycle design, it has a pronounced power spike at 6800 to 7200 which allows a Max horsepower to cc ratio at 40hp while using a gear reduction for the tractor prop. There is a new 440 4-stroke out for ATVs which is Ethylene Glycol/water cooled, which is really cool.

@LetsGoAviate

10 ай бұрын

I didn't know about this engine before your comment, but I see it was/is quite popular to convert for Ultralights.

Great video. Have flown 8 hours behind a AeroMarine V Twin and a few hours behind a HKS700E, and many behind Rotax 503/582. The HKS has less vibration at idle and low power settings compared to the V Twin/Rotax. All the engines are quite smooth at normal or full power settings.

@LetsGoAviate

10 ай бұрын

Great to hear from someone who's flown behind all those, thanks! The engine mounts will help reduce the amount of vibration that reaches the cockpit and rest of the airframe, so tiny amounts of vibrarion aren't always apparent. We had a 582 on the Bushbaby (similar to Kitfox), which had a weight bolted to the engine to improve the C of G. The mounting of this weight broke and had to be rewelded every few months due to vibration. Same happened to the exhaust mounts a few times.

@Gord-tk5ly

10 ай бұрын

@@LetsGoAviate Great videos. V twin suffers from its ATV roots in that it has a bushing instead of a bearing where it passes through the crank seal. Aeromarine had to re-engineer their redrive mount to incorporate a proper bearing as the belt drive put a side load on the shaft causing the oil seal/bushing to fail. CTV transmissions don't do that on ATV application. So a work in progress despit what their website says.

Thank you for making this video. It is really fascinating topic. Wold really love to hear your take on newly tested prototype engines like free piston engines. I have some small experience with hybrid engines in cars and their consumption really surprised me. It seems like a ideal fit for airplanes.

The Moto Guzzi 1200 cc engine would make an excellent powelant if paired with an epicyclic reduction gear.

I wonder when Yamaha will make a 270 degree crank inline twin aero engine?

I have many hours behind the Rotax v twin in its 4 wheeler and sxs it’s a natural for an airplane install especially when you could probably easily get 100 hp out of one. I’ve always thought i would try to convert one for one of my planes one day.

Lets go aviate🛩

B.M.W. for the Win!!! 🤠👍🇩🇪

I would be more inclined towards the boxer style engine. The width isn't a real problem at all.

Rotax 582cc twin look like Seadoo jetski engine design. Powerful and reliable

the 2-stokes are popular STOL engines, just so much power to weight like that....but i would rather the 4-stroke reliability in an air cooled twin with the gear reduction bringing up the power.

How do,you know all this and how on earth did humans ever invent this stuff! Just insane the brilliant people who came before us!

@yishaipiano3928

Ай бұрын

It is amazing

yamaha makes a 100hp 1000cc inline 3 made for the yxz side by side, with an optional factory indorced turbo kit. no integrated gearbox so its right there if anyone wants to do the conversion. not known for any issues other then the output shaft gauling when pushing over 200hp with mods like another keeway to corect it. sould be great.

I do like the idea of an air-cooled boxer 2-stroke. Good cooling being a boxer well balanced and a two-stroke doesn't need a set of camshafts on both sides

@mofayer

6 ай бұрын

Firing interval balance on a 2 stroke flat twin would be 360°, which is basically a 2 stroke 1cyl interval. That's why such an engine doesn't exist.

@060racing8

6 ай бұрын

@@mofayer I have seen two-stroke ultralight motors that 2-cylinder boxer 2-stroke the idea of only needing a single carburettor sounds like a good thing as it's less complexity and less weight pretty much like a 360 degree parallel twin like on an old British motorcycle

I was always wonder if the can am engine was 90 because it looked close but now I know its 80 degrees

Even the footpegs are offset on the BMW boxer.

As far as I’m aware the Aeromarine engine is based on a Chinese GK engine, which is pretty much a rip-off of the Rotax Can-Am. There’s a guy been flying his own home-grown conversion on a trike for a while now. There’s also a 1000cc version which I believe I’ve heard Chip Irwin say Aeromarine are looking at.

Who make the reduction gear drive for the BMW?

@LetsGoAviate

2 ай бұрын

Air Trikes (airtrikes dot net) makes one, a German company Take Off (GmbH) also makes one. I think there's more though.

NO twin engine is suitable for aviation because of vibration mode. Except twin 2 strokes that are at least like a 4 cylinder 4 strokes. the best aviation engine is flat 6 period, smooth as butter. I dream of a modern 3 cylinder 2 strokes with direct injection, Would be like a six 4T, but much lignter....

@LetsGoAviate

10 ай бұрын

Yeah there are no perfectly or even really well balanced twins (at least not without a counter/balance shaft). Agreed on the boxer 6, but they are loo large and heavy (and expensive) for Ultralights and light sport, which is why I think 4's and 2's will always pop up.

@clevernduruza8624

9 ай бұрын

@@LetsGoAviate 90°v twin is perfectly balanced

for what one of those HKS 700Es costs, one could probably afford to figure out an atmospheric Turbo system for it. maybe up to 1psi at sea level boost, giving a higher flight ceiling, and for sealed cabins that can hold some pressure. ( HKS should really make a Turbo Version )

@LetsGoAviate

10 ай бұрын

As far as I am aware the 700E has been discontinued. But there should be a few used ones around for a while.

@RulgertGhostalker

10 ай бұрын

@@LetsGoAviate oh no, that is sad.

@RulgertGhostalker

10 ай бұрын

@@LetsGoAviate someone should make a high over-square, ( like 1.5 over-square ) Side Valve Boxer Twin Turbo. that's how D-Motor does theirs; the over-square making the pistons area much larger, in relation to the valves. and the manufacturing costs would be much lower than a naturally aspirated OHV four; even With the Turbo.

@RulgertGhostalker

10 ай бұрын

@@LetsGoAviateconsidering the HKS is off the market; maybe D-Motor should consider adding a boxer twin, with a turbo, to their line up ? they have a six and a four.

@RulgertGhostalker

10 ай бұрын

@@LetsGoAviate they could keep the same bore, same pistons, same con-rods, same valve train, and same applicable case dimensions, and just de-stroke to accommodate whatever sea level boost figure gets them to 60 HPeak or so....it would need a new crank and camshaft anyway.

I have to go with Yamaha

What about the BMW 900 inline bike engine

@LetsGoAviate

6 ай бұрын

Would not be great in aviation in my opinion. Speaking under correction but it's got a 270° crankshaft, meaning the engine inherently has bad primary balance and ineven firing interval. To correct the balance it's got balance shafts, 2 I believe. The uneven firing interval is great for bikes but bad for planes as an even firing interval is desired.

You did not include weight and peak optimal RPM and HP. For example the rated 100HP is at 90% of red line. engine may not last at that RPM. Most of the time car and motorcycle engines are making 30% or less of rated HP. Getting a good PSRU is difficult and many fail. It's #1 weak link in all Auto / Motorcycle engine conversions. Also every conversion I have seen has higher installed weight. Also radiator installation often has more drag.

@LetsGoAviate

10 ай бұрын

I think a big factor that will determine how well an engine will last at that peak power are the vibrations. That's more what the video is about, not really peak power etc. It's also easy enough to lookup, whereas the vibration take a lot more research. For example the data on the Aeromarine or 80 degree v-twin isn't really available on the net, I had a create a model to confirm/establish vibrations and firing interval. That to me was the fun in creating this video. You are correct regarding the the PSRU. But I think that's only an issue if you convert something yourself and have to find one. If you get an engine that has a PSRU from the manufacturer (HKS, Rotax, Hirth) or even with the professionally converted engine like the Aeromarine v-twin there shouldn't really be cause for concern.

@gmcjetpilot

10 ай бұрын

@@LetsGoAviate I forgot to say well done very thoughtful comprehensive video. Your vibration video also excellent. You made a lot of great points. I just saw another vibration video... "PARALLEL TWIN: 360° vs 180° vs 270° - Ultra in-depth but EASY TO UNDERSTAND - ENGINE BALANCE". Your best worst LSA engine was excellent. I am being picky. It really has to do with my pet peeve of "conversions" of none aircraft engines. I have followed this topic since 1985. I heard over and over for decades how THIS ENGINE is "modern: and will be a Lycoming killer. None of them are to be seen in any number. The real world Cons. I know you are not doing that. You are doing a thought experiment. However with out many real world examples, having flown a fleet total of 1000's of hours, with document performance, it is all conjecture, which is fun and useful. However I am pessimistic and opinionated of any conversion. I have an open mind, and if your challenge or joy is to make one of these engines into an aircraft do it. HOWEVER these are not motorcycles or cars where loss of power means you pull over to side of the road and get tow truck. It may mean an off field landing in a not so great place. My point is these engines never produce the HP or equivalent thrust they promise , and the installation in an aircraft have many Cons often not considered. They can be made to work. However the builder has to be technical, excellent builder with high level of fabrication capability, enjoy spending a lot of time making it work, tinkering, even after it is flying. They plane will almost always be heavier, slower and have lower resale value. Where you bolt on a Rotax, Lycoming, Continental you go fly. It is VERY hard to beat a purpose built Lycoming, say O320/O360 for HP, weight, cost, support in the 150-210HP range. With the advent of LSA last decades and catching more traction, growing, the need for smaller (less HP) and lighter, cheaper engines is there. The cheaper part of LSA's is a big miss... These planes cost over $100K. If some entrepreneur can develop a motorcycle engine kit for popular kit plane that works well, cheap, gives equivalent performance of an aircraft engine, they may have a business, albeit not super profitable. Also finding used bike engines may not be that easy. Of course the Yamaha snowmobile engine is pretty amazing, just as an engine design. As you or someone said Yamaha may get into support aircraft. The Yamaha has been made to work on Steve Henry's STOL plane he flies in STOL competition. There are off the shelf PSRU's that seem work well and are reliable. I suspect the design of the Yamaha puts out a very smooth power pulse which is easier on the PSRU? However every PSRU is more parts, maintenance and potential failure point. ROTAX really is dominate in the sub 140HP category. The Jabiru, UL Power are there, but I don't appreciate their service history or support. I am suspect of them, and they are not cheap. UL Power is as much as a Lycoming, but so is a Rotax. Also motorcycle engines in small kit planes are competing with the small car engines that are on the market.

Don't forget most inline twin-cylinder engines run the crank pins side by side, how is the balance then??

@LetsGoAviate

10 ай бұрын

If I understand correctly what you mean, that's the 360° crank, so basically the pistons move up and down together. They have bad primary balance (cylinders not cancelling out each other's inertia), as well as very bad secondary balance. The only good thing is they have an even firing interval of 360 * 360. Mostly used on older motorbikes (and at least 1 new one I'm aware of), but I don't won't be great on airplanes due to the bad vibrations.

Your chart of Hp / cc needs one other column, (Hp/cc) / rpm ....Too relate Noise and Stress levels....

nice

There is NO best two cylinder engine (for anything really), unless it's a two stroke, or rotary. ALL two cylinder four strokes vibrate! The absolute minimum number of cylinders that can be used by a four stroke is THREE cylinders, either inline or radial.

@LetsGoAviate

10 ай бұрын

Yeah, but some are worse than others, and 2 stroke twins vibrate as well.

@LetsGoAviate >>> Great video...👍

270°?

@LetsGoAviate

10 ай бұрын

270° crank inline twin? Great on motorbikes, horrible for aircraft as it has more vibration and a less even firing order. If that is what you meant 🙂

@daszieher

10 ай бұрын

@@LetsGoAviate yes! Thank you for answering and please accept my apologies for the very much abbreviated question, I was in a hurry after finishing watching your video. 🤭

@LetsGoAviate

10 ай бұрын

No problem, it seems I was also in a hurry in my reply. It has more vibration, but a more even firing interval than the 180 degree twin, which is 270, 450.

@daszieher

10 ай бұрын

@@LetsGoAviate which means that when total mass (balance shafts, dampening engine mounts) is not an issue, the 270°-twin could be the engine of choice as it is able to deliver power more evenly to the PSRU and ultimately the propeller. I remember there being an analysis in the 80's or 90's for MotoGP in which (Honda?) looked at firing all (four) cylinders in one revolution and leaving one "dead" following. But I think it had more to do with rubber temperature (tyre). It would basically represent the inverse of the case of aircraft.

You have a lot of misinformation about the Phazer engine. A few friends and I have been running them for some time now. Even before yamaha teamed up with the company in Japan.

@LetsGoAviate

10 ай бұрын

Please do share. If I got a fact wrong somehow, I'd like to correct it.

@gdaytrees4728

6 ай бұрын

I don't see any "misinformation " in his chart. Didn't hear any wrong statements. What are you talking about? ...robot?

@Down_To_The_Bone_Garage

6 ай бұрын

@gdaytrees4728 The phazer has a internal balance shaft, the Rk400c clutch helps with easy start up, and less vibration then the rubber damper from the rotax gearbox. There's two gearboxes you can run with the phazer. 1: Skytrax gearbox, or 2: Ben Kairys phazer to rotax c or e gearbox adapter. I have the phazer in my airplane. I guess I must be a robot.

Answer: There isn’t a good non-aircraft engine to install on an aircraft. If you want to become another crash statistic install a snowmobile engine on the front of your airplane. You can feel pretty safe with a motorcycle engine on the back of your powered parachute because you already have a parachute when it craps out.

@WilhelmKarsten

7 ай бұрын

Mercedes-Benz and Porsche have both produced type-rated aircraft engines based on automotive engines... but this is certainly not indictive of most non-aero engines, most are completely unsuitable for aircraft

@greapsoho

Ай бұрын

Everyone I know with an ultralight has a v twin briggs

@davecox1697

Ай бұрын

I have a 24HP Briggs on my SD1, hundreds of hours of trouble free flying. Economical (80kts at 4 litres an hour), smooth and faultlessly reliable. Each to their own I suppose……