How about a Yamaha engine.
 

Here is a very nicely packaged engine weighing 120kg that produces 250 hp. It has a scavenger oil pump, engine driven supercharger, integral intercooler, less integrated efi than a car and is a very compact package. You can probably buy one new for around $10,000, all you need is a PSRU and radiators and away you go. Just kidding, I know it needs lots more. Anyway, just saw this new jetski engine by Yamaha and thought what if. What do you think Ross? Sound like it could be detuned to 200hp, or 180? Runs on regular unleaded too.


http://www.waverunner-fan.com/produc.../features.html

Yamaha certainly makes some nice engines. If memory serves, I believe they built the early Ford Taurus SHO engines and they built at least one of the specialty Corvette engines. However, there is a specialty company named Lycoming that makes engines designed for driving airplane propellers, and that need no modifications or redrives. Plus they are air-cooled, which, with an airplane (trying to keep things simple and light), seems to be a great platform for this engine. Perhaps a little expensive, but maybe not over trying to keep a cobbled together car engine and drive package working reliably.
Here's a link:
http://www.lycoming.textron.com/engi...fied/index.jsp

Yamaha was responsible for the SHO V6 but Mercury Marine did the LT5 V8 engine for GM.

1800cc will be working pretty hard to deliver 250 hp on a constant basis. I also suspect they use liquid (lake water) to air intercooling so you'd have to fit a good air to air to duplicate its performance in an RV.

Japanese engineering, engine design and manufacturing is at the top of the heap but it would be quite a project to fit a good PSRU to this and change a lot of parts to make it turn a prop. Probably very light and would last a long time derated to 150-160hp or so.

Interesting powerplant. I think you should get started.:)

If I was starting a 4 cylinder inline program I would seriously consider the GM Ecotec. The crate engines are $3000-$3500 and there is awesome support from GM on the race stuff with blocks, heads, cams, rods, cranks etc. These things are pretty light and capable of 1400+HP in full race trim. You could certainly produce 200hp for a very long time at low boost and low revs. Bud Warren is dabbling in these a bit. This is probably the strongest 4 cylinder engine you can buy today.

Ross, you are correct with your cooling concerns.

Most PWC make their power way up in the RPM band-----like 8000 or so, some even more.

IIRC, a prop that can absorb 250 HP is going to be limited to around 2800 RPM, so the gear reduction will be close to 3 to 1. This will not be too easy to manage , I suspect.

Thanks for the replies.
 

Even you Captain Ron, but we already know about Lycomings and Continentals. Heck, I even own a Lycoming and it only came apart on me once so far. Just amazed at how Yamaha and other manufacturers put together so many types of engines and how cleanly a big manufacturer can package a powerplant. It's a shame how little investment there is for light aircraft due to federal regulations and liability issues. Can you imagine the aircooled engine Honda could put together? Or what Yamaha could design? Water cooled as well. Boron coatings and dimpled sleeves like Yamaha has in its top of the line V8 outboards. Purpose built engines and PSRUs that would be designed together. It's fun to speculate but I guess it will never happen, especially with $5 avgas.

I was at the Indy 500 last week compliments of the Chip Ganassi team, and watched as the exclusively Honda-powered cars performed without, I believe, was a single engine incident for the entire race. Impressive, but I would have paid to see and hear the old Offenhauser four-bangers keeping pace with the Hondas, albeit while running 120 in.Hg of turbo boost! No real point here, but some of the old tried and true stuff was run for decades, only to be pushed aside by Fords for a few years, various other manufacturers including Oldsmobile of late, and now Honda. The cars are marginally faster now, but is it thanks to the engines, or is it chassis and tire etc. improvements? Reliability is certainly there, but each engine costs more than most of us will ever invest in planes and if there is a problem they simply take a new one out of its shipping container, put the suspect engine back in the container, and ship it back to Japan. Kind of a "Power by the hour" lease, and kindly keep your hands off our engines! And, they only need to be good for 500 miles! Sure, you might need a jug or other repair on the Lycoming during its lifetime, but it will almost certainly be a long lifetime if history is any judge.
Thanks for putting up with rant from an old geezer.

Bah...Humbug!
 

Here's a REAL Yamaha Engine! :D
(My RZ500 Motor)

4 strokes are too many and one stroke is not enough. :rolleyes:



Valves are for toilets.. :p

I love the smell of 2-stroke oil in the morning.

IRL uses a single engine supplier, Honda. They run 3.5l nautrally aspirated V8 engines that make around 700Hp, reving to "only" 11,000 RPM. Champ Car (now officially the red headed stepchild of the IRL) ran 2.6l (?), low-boost turbocharged V8s that made closer to 800Hp; these were derrive from the Cosworth F1 engines. They ran were limited to about 13,000 RPM, way down from what they were capable of, in order to increase reliability. Both of these engines rarely fail during races, which is the idea. Instead of F1 which is about driver, team and constuctor, spec series like IRL remove the constructor from the competition, reducing cost at the expense of innovation.

Modern F1 engines (2.4l normally-aspirated V8s) are limited to 19,000 RPM by rule but are capable of more. They use very radical technologies to achieve this (e.g., valves use a pneumatic system instead of mechanical springs to combat valve float at these high RPMs). Engines frequently fail during races and practices, sometimes spectacularly, and they are very, very expensive and require a lot of care and feeding (hot fluid pre-heating prior to start-up).

Anyway ... back to airplanes ... I have no interest in the most powerful engine out there. I'll take reliability over output. The Rotax is high strung enough for me, but it seems to be durable and reliable.

For me, engine choice would be about what it brings over the Lycosarus. Efficiency? Smaller size? Less weight? We know the Lyc can be improved in these areas, but darn is it reliable. I'm happy flying with the Rotax beasuse in the 100Hp class, it is lighest and smallest.

To parahprase a racing saying, "To finish first, you must first finish"

TODR

Having spent a good bit of time on Yamaha wave runners with the normally aspirated 1000cc engine, I can say that I dislike the ultra high RPM's. These things flat out scream. 7000RPM is needed to simply get going at a decent rate. Cruise RPM is north of 8000, and high speed cruise is 10K!

Sure they last 300 hours in the water. But a good number of those hours are spent putting around.

Not sure about this one.