An alternate engine question

[Modest Pilot]

The Franklin engine.

 

 

[hfrensch]

David,

 

I worked for Mitsubishi Motors Australia,I have/had friends in the engine development GM Holden and Toyota and know their testing is as severe.

 

You need to know your product is reliable when you give 10years or 160,000km warrenty on the drivetrain.

 

Brett.

 

The Toyota motor is a sure money bet.I have it from a good source that the 100HP Rotax have had major block problems with a number havin to be replace at 600hours.

 

Cheers Helmut

 

 

[Yenn]

When you look at the engine failures, from my recollection most of them are auxilliary equipment failures. I had a broken plastic fuel line and it had done only 18 hours service in about 6 months, it was fuel grade line. I know of several Rotax engines that have had ignition module problems.

 

When I ran an old Jabiru 1600, which I knew was a bit sad I had a rocker cover come adrift, also a blown head gasket, but neither caused the engine to completely fail. The head gasket blow allowed me to complete a circuit and land and the rocker cover provided a few interesting moments for onlookers on the ground as I disappeared in a cloud of smoke as the oil hit the exhaust, luckily I quickly worked out what had happened.

 

Most engine failures seem to be 2 stroke, with cold siezures being high on the list.

 

4 strokes suffer most from carby ice, but that is a training problem and can be dealt with if recognised early. Apart from that running out of fuel cannot be blamed on the motor.

 

 

[Guest basscheffers]

You need to know your product is reliable when you give 10years or 160,000km warrenty on the drivetrain.

Compare that to the Rotax which is 12 months / 200 hours for the certified version and an incredible "this is how much we trust our own engines" 6 months / 100 hours on the UL versions!

By comparison, 160,000km would be about 3500 hours driving your car. (by which time the Rotax would be ready for its third overhaul if it lived that long)

 

 

[Guest Rocko]

The UL only has a 6 month warranty, NEW???

 

Jees Louise! A carton of milk has a longer expiry than THAT!

 

 

[Modest Pilot]

160,000 and ten years; markrting spin! Try running it at 75% power not the normal car cycle of 18% with short bursts of full power. History is you will be lucky to get 200 hours in an aircraft. The Lexus /Toyota engine is a fine bit of machinery but is a V6 with all the odd vibrations that configuration brings. That's why most have a balance shaft running at twice engine speed. If you must have an alternate engine I,d go for a Subaru, VW, Corvair, Izusu, Suzuki, Honda in that order. However if you have a large cheque book (very large) have go and let us know the results.

 

 

[hfrensch]

Every one is entitled to their opinion. But I would have thought 400hours at 5600rpm at maximum power is harder than running at 70% power.

 

I also am not aware of an V6 engines running balance shafts. I know of many in line 4 cylinder in line engines engines that use the counter rotating shaft system to balance the engine.

 

The Supermarine Spitfire now use the ISUSU 3.0L V6(made by Honda) and the Titan Mustang use the Suzuky 2.7L V6 I am sure both these will be super reliable and will exceed 1000hours before overhaul is required.

 

Cheers Helmut.

 

 

[youngmic]

Rocko,

 

I for one think your onto something here with the current crop of jet ski engines, and have wondered for a long time why no one has had a serious look at outboard engines as well. These engines are light and designed to operate with a flat torque curve and run a horsepower absorbing load at WOT for extended periods.

 

Clearly there would still be a mountain of R&D to make them suitable but the core engine does look like a promising start point.

 

As a professional pilot for 20 years who makes his crust flying low level aircraft I'm keenly tuned to engine reliability, I also own a Vari-eze powered by a Continental 0-200 100hp engine. It is largely agreed by those that fly the Vari-eze's that engine reliability is of the highest importance, these aircraft are not designed to survive an off field landing. Nothing I have seen to date compels me to change my engine to either Rotax or Jabiru, (and certainly not an auto engine derivative) they're good but not good enough. Maybe in time, I'm certainly watching the development of the 3.3 Jab. I commend both Jabiru and Rotax for their considerable efforts achieved to date.

 

One of the beauties of this (O-200) little engine is its simplicity. I would not consider that an electronic managed fuel injection system would give me substantial benefits in either reliability, economy or increased power. Certainly some benefits in economy but only small due to the fact that not much fuel is being used anyway. Similarly air cooling doesn't fail, I like that. Increasing volumetric efficiency with a multi valve design tends to compromise cylinder head strength whilst increasing the amount of stressed moving parts. Modern ignition systems are one area where significant improvements can be made, and are. Many home builders are enjoying improved efficiency and reliability from retro fitted variable timing solid state systems.

 

At some point in their operational life nearly all aero engines will be asked to be the sole factor in deciding whether the occupants live or die. Within the company I work for not a single pilot is yet to state they feel safer between the Thielerts than they do between a pair of IO-540's

 

One of the greatest attributes of the current certified aero engines is that they have manual mixture control, and those in the know curse Jab and Rotax for the lack of this feature. I often feel that a lot of the pro auto engine camp are really pilots that haven't learned the benefits and real economies that can be achieved by manual mixture control. And in disgust with perceived inefficiencies go searching for alternatives. I am not an anti auto engine proponent but wise to the benefits of a rugged simple purpose built design.

 

In fact Thielert who are the only company to have a serious go at a modern piston design have found that out, as have our pilots who fly between their engines, the level of electronic dependency has turned out to be their Achilles heel. We have suffered many aborted flights due to partial power losses caused by the electronic fuel injection system. In time these problems will be solved but there is a way to go yet.

 

The fundamental laws of chemistry dictate that to achieve the most efficient use of fuel you need to run your engine at 35 degrees lean of peak EGT, cars can't do this because of there mission role but Lycoming and Continentals can and do. My 0-200 Continental produces 75 hp (75% MCP) for a fuel burn of 19 liters/hr about the same as a Rotax 912S. It is slightly heavier than a Jab or Rotax but the new D model 0-200 for the C162 Skycatcher has apparently shed some weight so the difference is small.

 

And the O-200 Continental is one of the most dated aero engines in service, literaly back to the 30's

 

On the matter of warranty, in the business of making money as aero engine manufactures are why would you put the company in the line of litigant lawyers with extended engine warranties and the prospect of an unfortunate failure and death, one strike and your out.

 

Still at the end of the day sensible development in the RIGHT aircraft of potentially beneficial design advances should be heralded.

 

Just another opinion.

 

 

[Guest ozzie]

Brand new 2 stroke - Recreational Flying

 

this asian jet ski engine was advertised here. just needs a gear box. one potential problem that has been mentioned here is the fact they are designed for raw water that is continuously cold. not much volume around the water jackets, recirculating hot water could cause cooling difficucties.

 

If i was going down this road i would be looking at that Honda 4 stroke engine. it would be reasonably priced as the whole PWC was ticketed at around 14,000us.

 

ozzie

 

 

[sain]

There are some interesting engines floating around in the UAV world at the moment - things like:

 

http://www.swbturbines.com/products/TurboShaft.htm and http://www.swbturbines.com/products/100_shaft_hp_turbo_shaft.htm

 

which is a 99.6hp (SLS whatever that means) 18.5kg minature turbo prop engine. It'd be very interesting to see this strapped to the front of something like a Corby Starlet, though weight and balance may be an issue.

 

 

[Guest sypkens]

Just another opinion.

Great post Youngmic!

 

Even i understood the mechanics of the points you made and I am dangerous with a spanner.

 

Jan

 

 

[Guest basscheffers]

On the matter of warranty, in the business of making money as aero engine manufactures are why would you put the company in the line of litigant lawyers with extended engine warranties and the prospect of an unfortunate failure and death, one strike and your out.

I am not a lawyer, but I am pretty sure product liability does not end when the warranty runs out! If you make something that is fundamentally flawed but that flaw does not show up until a few years after the warranty has run out but tends to kill people you would be out of business.

I guess the reality is that engine failures are not the main cause of fatal accidents because most of us are diligent enough to plan for it. Any damage caused by a forced landing is absorbed by our own insurance. It's just XXXXty we have to pay for the engine repair simply because Jab and Rotax charge 20 grand for an engine and still can't make it reliable.

 

It would be interesting to see if the Skycatcher's Continental is as reliable as previous models and ends up in more designs. When we get the 760kg rule, the extra bit of weight should not be a problem anyhow.

 

 

[Guest ROM]

"Sea Level Static" HP, I think, sain.

 

Power goes up rapidly as airspeed increases and the ram air effect contributes to the pressures in the combustion process so Sea Level Static power is a constant against which aircraft gas turbine power outputs can be compared.

 

High Specific Fuel consumption per HP/ Hour and slow initial acceleration of the pure jet is the achilles heel of the turbines although the Turbo prop version looks very interesting indeed when they do some more development on this.

 

Small companies and lack of vast wads of money to finance development is again a problem and is holding back all sorts of interesting power plant developments.

 

With the recent developments and massive increases in the storage capacity of the Lithium-Ion batteries currently in the laboratories, we may be seeing the development of electrically powered or fuel celled powered aircraft not many years away.

 

There are already a couple of commercially built pure electric / LI-ion battery powered self launching gliders on the market.

 

The Li-ion batteries are currently the best storage capacity batteries on the market and are good enough to take a 400 KGs glider to the equivalent of a 20,000 foot climb.

 

Still a long way from a good long distance cross country but it is still very early days.

 

Li-ion batteries swell up as the Lithium ions migrate into the silicon anode when charging and can actually explode.

 

However some very recent research has shown that the use of silicon nano wires as the anode instead of ordinary silicon can increase Li-ion battery capacity by at least a factor of 10.

 

This puts the Li-ion battery powered vechile well in the running as a viable city get about and a moderate distance highway vechile.

 

There are a number of other power storage technologies in the research units around the world and there is no doubt that an electrically powered aircraft with sufficient range and very rapid recharge capabilities would be a darn sight safer, cleaner and far more reliable than any piston engined power source.

 

Vechiles using this type of electrical power from batteries are only a few years away and I would hazard that the aviation community won't be far behind in their adoption of a either battery powered aircraft or maybe more likely, fuel celled, eletrically powered aircraft which is another derivative of an electrical power source.

 

Impossible!

 

Ten or fifteen years ago, nobody foresaw the explosion of aviation activity and the rapid increase in pilot numbers in the Light Sport Aircraft field.

 

A different way of looking at things by a few far seeing individuals created this new aviation resurgence.

 

Now we are seeing new designs and new technologies emerging that are leaving the old comfortable, conservative and what was a slowly dying GA scene far behind.

 

If electric / fuel celled powered aircraft emerge in the near future, it is most likely to be from the manufacturers of the LSA category as they try and stay one step ahead of some fierce competition.

 

It's going to be a quite interesting time in the aviation world in the next few years.

 

 

[Guest basscheffers]

The reality of electric propulsion

 

If electric / fuel celled powered aircraft emerge in the near future, it is most likely to be from the manufacturers of the LSA category as they try and stay one step ahead of some fierce competition.

It's going to be a quite interesting time in the aviation world in the next few years.

I think that will more likely be "the next few decades". A practical fuel cell costs about $1M today and that is not going to come down in price enough to compete with current engines any time soon. Not to mention the cost of producing hydrogen, for which you need electricity which we all but exclusively generate from coal and gas here in Oz, negating any environmental advantages. On top of that, grid to hydrogen to fuel cell to motor is about 25% efficient whereas grid-batteries-motor is 75% efficient which leaves hydrogen dead in the water for a long time.

When we have a look at Lithium-Ion batteries and electric, the situation doesn't look too good either. If you look at the Tesla Roadster, I reckon you should be able to make a plane out of not much more materials. That could bring the price in-line with what you pay now for a nice factory built ultralight. Unfortunately, it won't be an ultralight at over 1200kg!

 

Looking at the specifications, the batteries store 53kWh which in standard tests gives it a 350km range. (would suit me perfect for a car, by the way) Now 53kWh means that if you draw 53kW of energy, you will drain the battery in just one hour. To drag those 1400kg (plane, passengers, cargo) comfortably into the air you'd certainly need a 200HP engine, or 150kW, which running at 70% would be 105kW. So basically, you'd empty out the batteries in half an hour.

 

Unless there is any major breakthrough in batteries (there haven't been any, ever, just incremental improvements) it isn't going to happen any time soon I am afraid. However much I might like it to!

 

Cheers,

 

Bas.

 

 

[Guest ROM]

Technology on alternate power sources to the hydro carbon fueled piston engine is rapidly moving ahead.

 

The driving forces behind this new attitude to alternate power sources is the price of oil, the unstable political situation surrounding the major oil reserves and the questions about the long term continuity of the supply of oil.

 

This leading to rapidly accelerating research into a number of promising alternate power technologies.

 

Obviously some of these technologies will drop by the wayside but some others will be found to be suited to particular sections of the market.

 

We may never again see just one single technology, ie; oil and the piston engine powering nearly all of the world's mobile equipment.

 

As an example, NASA has already done a study on small electrical powered aircraft using the French MCR-01 kit built LSA type aircraft as the base aircraft.

 

The info and research paper can be found here; http://www.grc.nasa.gov/WWW/RT/2003/2000/2400berton.html

 

Google "electric powered aircraft" and you may be a little surprised at just who is working on electric powered aircraft

 

Have a look also at this site; http://www.airventure.org/2008/news/080612_electraflyer.html and this site also;http://www.ElectraFlyer.com/index.html

 

This all electric battery powered aircraft was supposed to be at Oshkosh but I don't know whether it appeared.

 

It is claimed to have a 70 MPH cruise and a 1 1/2 hour duration with a top speed of 90 mph.

 

American performance claims are usually pretty suspect but at least it is flying.

 

And also this is with the present generation of batteries, not the x10 capacity Li-ion batteries that are still to come out of the laboratories.

 

Apparently a couple of American model helicopter pilots, probably battery researchers, are already using the silicon nano-wire Li-ion batteries so my son informs me.

 

He is well into the model heli game.

 

No argument that there is a long way to go yet in developing satisfactory alternative mobile power sources to the piston engine but do not underestimate the speed of the technology advances nor the deep suspicion that now prevails about the continuity of oil supply.

 

This suspicion and unease about the reliability of future oil supplies is driving the rapid advances in alternate mobile power sources as time is now the essence to be able to have alternative technologies operational if oil supplies go to hell in a bread basket

 

And aviation is going to be right in there as it happens.

 

 

[Guest basscheffers]

I certainly agree that things will get better, I am probably just more pessimistic about the timeframe!

 

I also think that aviation is going to be a very late adopter, not an early one. There will be some experimenting (as is already being done) but the mainstream of aviation will take a long time to convert. The only way I can think of powering an airliner in a "green" way is burning hydrogen (i.e.: not a fuel cell) as anything else is way too heavy. And tanks full of hydrogen is just way too much of a safety issue.

 

Instead, I imagine land-based transport to ween itself of oil before anything else, leaving the dwindling supplies for aviation and sea transport - and not to mention to make plastics and such. Currently, I simply do not see anything (practical or otherwise) on the drawing board that stands a chance to power a 747 from here to London.

 

 

[Guest ROM]

I agree totally with your comments on the big airliners and etc, Bas, but the biggest and most rapid advances are going to be in the vechile sized engines and vechile horse power ranges.

 

It is right in this range that the engines and HP requirements for the now very competitive LSA class aircraft fit.

 

Batteries and fuel cells advances are concentrating on and making rapid advances for exactly these vechile sized [ electrical ?] power plants and as well there is a very big effort being put into making all the new power sources as light as possible just to get the efficiencies up on road vechiles.

 

All very good news for the future of alternative non hydro carbon fuelled power plant types for LSA and light aircraft aviation.

 

Heavier aviation may have to wait a long time before alternative power sources become available for their operations as will a lot of the mobile heavy equipment but it will eventually come and the piston engine will become a legacy engine which will have to have access to oil based fuels for perhaps another century until they are just plain worn out.

 

Steam power is a good example here as it took 50 years or more after the development of the piston engine before steam faded out for mobile vechiles; ie trains.

 

Steam is still the most important power plant type even today in the 21 st century when we look at the big coal fired electric power stations.

 

Likewise, hydro carbon fuelled engines will continue to fill a large niche in the world long into the foreseeable future.

 

Incidentally, hydrogen at very high densities can be and is being stored in metal hydride type materials with a new hydride material announced only a couple of weeks ago that has very high hydrogen storage densities exceeding hydro carbon fuel energy densities and which needs only quite low temperatures to release the hydrogen from the hydride sponge.

 

The safety of these metal hydride hydrogen storage systems is a lot better and safer already than the storage and transport of our present hydro carbon fuels.

 

 

[Guest Rocko]

Chinese engines? SHUDDER!

 

Concerning cheap chinese Jetski engines.

 

Having had a friend who bought a cheap POS "Polaris copy" get sji from China, all I can say about their reliability, is you'd have to have a death wish!

 

We called his Ski "The Hung Dong submersible", for all sorts of reasons....the obvious most of all. It was complete, total and absolute crap, top to bottom.

 

Would you spend $3000 on a crappy Chinese engine for an aircraft?

 

Safer playing Russian Roulette! ;)