Engine Types

[Guest LJS]

Has anyone investigated the possibility of using motorcycle engines (4 Stroke) as powerplants for RA aircraft?

 

I used to own a Yamaha YZF R6 and this little beast's engine put out 120 HP from a 600CC motor and I was just wondering whether one couldn't slot one of these into a trike or 3 axis aircraft

 

Your Thoughts?

 

 

[Guest palexxxx]

That's a lot of horsepower from such a small motor. 600cc is only 36 cu. inches. It would be the equivelant of a Lycoming or Continental engine of say 520-540 cu inches producing 1735 - 1800 horsepower.

 

I think the engine mightn't survive too long producing that much power.

 

 

[Guest Andys@coffs]

In fact what palexxx is talking about is the reality that motor vehicle / cycle engines may well be rated to a particular hp but in practical day to day use rarely are called on to produce that power and when they are called on its generally only in very short bursts with long times between calls.

 

In aviation engines the engine is called on to produce full power for take off and climb, perhaps up to 20 minutes and then the power request drops to say 75% for hour after hour.

 

If vehicle engines had to produce power for the same periods of time they would need to be derated down significantly so as to assure a level of reliability.

 

The 120hp engine you speak of has as its possible closest aviation engine (akbeit 2 stroke rather than 4) the rotax 582 (approx 600cc's) and is capable of producing 65hp for a useful life of only 400hours between overhauls, where the overhaul will replace the crank and probably pistons. A road bike having a useful life of 400hrs would be percieved as total rubbish.

 

Hope that clarifies it a bit for you. Generally speaking if using std vehicle engines was as easy as it might first appear we wouldnt be all paying 10k-14k for aviation rated engines by choice.

 

Regards

 

Andy

 

 

[Captain]

LJS

 

 

 

That R6 engine of yours is redlined at about 15,000 or so, from memory, and it uses the revs to produce the power. A great engine for the track and road. She'd be interesting to sit behind in an aircraft.

 

 

 

Search the net for BMW boxer engines that are used in aircraft and you will see examples of the downrating that others refer to.

 

 

 

Hope this helps.

 

 

[Yenn]

The engine from the Virago was put into a Nieuport homebuilt in the USA years ago and supposedly went well. I have also heard of a Honda Goldwing being used in home builts with the added advantage that you can retain the gearbox using second gear and the clutch is still operable.

 

The real situation is that the only people who use oddball engines are usually oddballs themselves, or maybe experienced auto engineers. We have never had more than a handfull of auto engines used and the VW and Subaru EA81 seem to be the only ones used in quantity. Personally I feel happier behind a Jabaru than a VW.

 

 

[slartibartfast]

A friend here in Canberra is putting a BMW 1150GS into his Tiger Moth. He's getting a lot of help from Germany where it's all been done before.

 

 

[Guest LJS]

A little R&D

 

Hello Gents,

 

Having done a little bit of research since I first raised the question regarding powerplants for aircraft I have found some rather interesting information regarding the types of engines that have been slotted into aircraft!

 

The best - it seems - that I have found is a little 3 Cyl Suzuki engine, the Suzuki G10 which seems to give sterling service as an aero engine!

 

For all those that are interested you can read about the use of this little engine here:

 

http://www.airtrikes.net/engines.shtml

 

while your'e reading you will come across the section detailing the Turbo Charged cousin of this little engine that apparently gives the 912s a little bit of a whipping!

 

Hmm Rotax has competition??

 

 

[Guest check-in]

I ride a Guzzi California and get the impression that the engine is very under-stressed. By today's motorbike standards the horsepower is not all that great for an 1100 cc lump, but the low end torque is good. Has anyone ever put one of these in a light aircraft?

 

 

[facthunter]

Guzzi power.

 

Yes it has been done. Being 90 degree it has reasonable balance. Nev..

 

 

[Steve L]

Heres two vids of harley engines fitted in couple of zodiacs.

 

http://www.youtube.com/watch?v=tptYb...eature=related[/COLO" 

 

https://www.youtube.com/watch?v=vIs45...eature=related"]http://www.youtube.com/watch?v=vIs45...eature=related[/color

 

 

 

The later twin cam and ballanced engines (which i believe were porche designed) dont have the problems the earlier models suffered. Mine (in a 2000 model nightrain) has done in excess of 100.000ks mainly in the US of good ole A, two up pulling a trailer, oil change every 20 thou and has never had a new spark plug. I dont need to add any oil between oil changes, nor do ever have any starting problems.

 

Another plus is they are high h/p, (between 80 and 130 depending on model) light and dry sumped

 

steve

 

 

[facthunter]

Porsche designed.

 

The V-ROD has the engine that is allegedly porsche designed with 4 valves/ cylinder and liquid cooling'. The Other (air-cooled) motors are so-called evolution engines developed and considerably refined from the earlier series of motors, which date back to (well how long is a piece of string) but the 1936 knucklehead could claim ancestry.

 

... I don't think that the engines will weigh any less than the new flat four Continental 0-200D, when a reduction set up is added.. The BMW based on the 1200 GS, comes out pretty heavy as far as it appeared when last I looked up the engines , and you have two cylinders instead of 4 , in both cases, and consequently, a much "lumpier" unit as far as power delivery, idling and starting is concerned. This subject has been run at some length previously, the general view being that aero engines have special requirements as they have to sustain full throttle for 5 minutes minimum and do not get much rest on cruise either, so generally a lazier oversized motor is preferred to a high horsepower for capacity unit in the interests of long life and reliability. Nev...

 

 

[Steve L]

Thanks Nev,

 

I stand corrected, I was under the impression that porsch had imput in the TWIN CAM engines as well as the V ROD. This I learnt from the Harley factory when I done a tour of the engine plant back in 2003.

 

Check out http://www.skyray.us/ its very interesting

 

Steve.

 

"All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find out it was vanity: but the dreamers of the day are dangerous, for they may act their dreams with open eyes, to make it possible."

 

T.H. Lawrence

 

 

[facthunter]

Public relations re. H.Dav.

 

They might be putting that view out because it would not do them any harm to be seen to be associated with Porsche.

 

.... The motors were re-engineered with a view to increasing their design longevity, particularly with regard to fatigue life of the connecting rods, and durability of the bottom end (generally beefed up). they have gone to a lot of trouble to get cylinder bore dimensional stability and good piston fit and sealing. The head metal is supposed to be pretty exotic also. I feel it could be claimed that they have been successful in producing a reliable bike with an excellent finish.

 

I would like to know what head temps the engines run in aircraft, and most V-twins that are dry-sumped need more crankcase volume than they have ex-factory to get satisfactory oil scavenging at high revs. Retained oil causes friction with the flywheels and a large power loss with lots of heat. It would not be very difficult to modify the sump to increase its volume. ( This had to be done on the oval-track racer, the XR-750 ) Nev...

 

 

[Guest Peggy2]

Gyro flyers swear by the Subaru engines and some have been tweaked to put out around 240 HP.

 

I am in the process of putting one together for my Pegasus microlight with the help of an L2.

 

Here's a video of a trike using this engine.

 

https://www.youtube.com/watch?v=6QEDxTY8FYM"