Honda Viking 170hp engine in Jab.

[onetrack]

So, you would rather a Toyota diesel than the Suzuki in a Jabiru? ...

No, you're taking my crude comparison to the extreme. All I'm talking about is that there are two important figures associated with engine output, and they are inextricably linked.

 

The design of an engine has to be tailored to the specific proposed style of use - and you can tailor both torque and HP/Kw output to suit the requirements of the required use.

 

An aircraft engine needs a high torque level, and that torque output needs to be high at the relatively narrow operating RPM of aircraft engines.

 

The loads imposed on a motorcycle engine are vastly different to an aircraft engine. Aircraft demand an engine capable of constant high output, and a high level of torque within the aircraft engines narrow RPM range.

 

The following website discusses some good torque and HP points, under the heading of "general observations".

 

Power and Torque: Understanding the Relationship Between the Two, by EPI Inc.

 

Engines can very rapidly become unreliable when they are utilised for purposes outside their projected-use, design parameters.

 

 

[geoffreywh]

Apples and Oranges people........Torque is hp divided by rpm................................just gear the Hayabusa down enough and it will pull the Toyota up the side of a house. Otherwise ....I give up on this debate.

 

 

[turboplanner]

Apples and Oranges people........Torque is hp divided by rpm................................just gear the Hayabusa down enough and it will pull the Toyota up the side of a house. Otherwise ....I give up on this debate.

Wrong way round; an engine has top have twist first, the torque. Horsepower includes a time element (revolutions per minute), so Horsepower = Torque multiplied by rpm.

If you gear an engine down, that is multiplying the torque at the geared down end.

 

 

[bexrbetter]

On a dyno for 30 seconds, yes. In a street race for 1 minute, yes. Now try to run that level of power for a number of hours on end.

No problem at all, all modern engines will run full load for as long as you want. The durability test cycles for modern engines undertaken by most manufacturers now are well beyond the aircraft engine certification standards.

 

This is constantly stated as an anti-automotive engine argument with no evidence to back it up. Some hypocrisy as well because many people who post these falsehoods then go jump into their modern car and enjoy all the fruits of those durability tests.

 

"Oh but I only use 20% of the engine in my driving", yeah but you live in Australia, go to other countries and see how they treat cars.

 

 

[Paul davenport]

No problem at all, all modern engines will run full load for as long as you want. The durability test cycles for modern engines undertaken by most manufacturers now are well beyond the aircraft engine certification standards.This is constantly stated as an anti-automotive engine argument with no evidence to back it up. Some hypocrisy as well because many people who post these falsehoods then go jump into their modern car and enjoy all the fruits of those durability tests.

 

"Oh but I only use 20% of the engine in my driving", yeah but you live in Australia, go to other countries and see how they treat cars.

There seem to be a lot of people who like to say that something won’t work but have not tried tried it. Auto engines are tested to destruction and auto company’s have far bigger budgets than any aero manufacturer . I would fly behind a Honda any day as Bex said it’s just too heavy for your application

 

 

[planesmaker]

Some of the P plate drivers around here seem to use full power whenever possible :)

 

 

[onetrack]

Auto engines are tested to destruction

Do you have any verifiable proof of that statement? Testing engines to destruction is the very earliest, crudest method of testing - but it doesn't yield viable information on many components strength or durability - because, often, many components are damaged in any engine destruction. Manufacturers today do carry out accelerated wear and durability testing, but these tests are not done via total engine destruction.

The engineering reference handbook for comprehensive engine testing is, "Engine Testing, 3rd Edition", by Martyr and Plint. This tome covers all aspects of engine testing, but nowhere does it mention, testing to destruction.

 

Interestingly, here is an excerpt from the foreword of the book, which shows the potential problems associated with extensive modern engine testing ...

 

The advent of engine control units (ECUs) containing ever more complex maps and taking signals from multiple vehicle transducers has entirely changed the (testing) situation.

The ECU monitors many aspects of powertrain performance and makes continuous adjustments.

 

The effect of this is effectively to take the control of the test conditions out of the hands of the engineer conducting the test.

 

Factors entirely extraneous to the investigation in hand may thus come into play.

[Brett]

 

Pity these ecoboost series engines are all too heavy. ... im sure most manufacturers test to a similar standard on dyno's.

 

I saw a similar dyno test done in real life at ford years ago.

 

I believe the 1.0 litre ecoboost Fox engine has won engine of the year for 5 or 6 years running...or something like that anyway...

 

 

[turboplanner]

Do you have any verifiable proof of that statement? Testing engines to destruction is the very earliest, crudest method of testing - but it doesn't yield viable information on many components strength or durability - because, often, many components are damaged in any engine destruction. Manufacturers today do carry out accelerated wear and durability testing, but these tests are not done via total engine destruction.The engineering reference handbook for comprehensive engine testing is, "Engine Testing, 3rd Edition", by Martyr and Plint. This tome covers all aspects of engine testing, but nowhere does it mention, testing to destruction.

 

Interestingly, here is an excerpt from the foreword of the book, which shows the potential problems associated with extensive modern engine testing ...

They are usually tested on a dyno, with the load which the application will normally produce, and with the rev variations based on the application. (If the application is variable load (motorcycle, car), the revs and loads will go up to sumulate a burst of acceleration, then down, to allow the engine to cool; if the application is constant load (boat, semi trailer, aircraft) the dyno will apply the designed load at constant rpm).

A series of engines are run on the dyno under these parameters in the hope that they will last forever. Since we are not in fairyland, and designers with the exception of Phil Irving, don't manage to get everything right, some excessive wear factors or failures might occur on thye first engine. These failures are repaired with a redesign, and the engine makes more succcessful hours, and so on. As you say, durability is one of the key targets along with reduced emission, reduced nose, reduced vibration and better fuel economy. The last thing you want is destruction, for the reasons you said.

 

In terms of cars, most will make the equivalent of 500,000 to 800,000 km these days (so people are usually selling them WAY too early), and Heavy truck engines vary from around 650,000 for the crap to 1,500,000 for the better brands.

 

I stress that the engines are designed and the dyno testing done, based on the design use, not the thought bubble of some aftermarket opportunist looking for a cheap way out.

 

A truck engine designed for intermittent use will fail quickly on line haul.

 

A car engine with a reputation of reliability will fail quickly if it's loaded up with a caravan, giving it a constant cruise load at a weight above that for which is was tested.

 

Same applies to a motorcycle.

 

An aircraft application will apply the constant loading that a car engine was not tested for, so it becomes an unknown quantity; some might survie, some might not.

 

 

[Paul davenport]

Written evidence no ,but having owned a dealership and worked for a Japanese auto manufacturer for the past 40 years attending many training sessions I can repeat what we we told of their testing regime as witnessed by them selves at the factory. Engines run at full load for 24 hours ,all parameters recorded,engines then dismantled inspected assembled and re run and tested again, when some thing showed premature wear or failed it was modified and the testing went on. Engines of the same series but turbo charged, undergo a redesign internally beefing up already strong components to take a modest 30% increase in power. I had the opportunity to sit next to a race car engine developer at a the release of a new car who was doing a turbo up grade on the Mazda MX5 and he stated that the engines from the factory have an 80% over engineered power increase factor. I own and fly behind a subaru EA81 motor and a j230 so I have some experience in both fields, people who tell me of what motors can and cannot do usually do not have any practical experience

 

 

[Old Koreelah]

... Testing engines to destruction is the very earliest, crudest method of testing - but it doesn't yield viable information on many components strength or durability - because, often, many components are damaged in any engine destruction. Manufacturers today do carry out accelerated wear and durability testing, but these tests are not done via total engine destruction....

I believe PSA tested ten or more Peugeot Diesel engines to destruction a decade or more ago. The story was mentioned on the Jodel Forum by a builder who seems to have been involved. After being asked what service life he expected from the engine, he quoted 10,000 hours (yes, ten thousand). This was based on a batch of engines being tested until the first one failed- a dropped valve- at 12,700 hours.

 

 

[jetjr]

Arent we crossing engines stories here, the reliability of general auto engines and heavy vehicle diesels isnt what we are looking at.

 

BUT I did have some short time with Toyota engine developers who clearly stated Australian duties were the toughest they had encountered worldwide.

 

Their severe test regimes involved not exceeding 60kmh off any sealed roads.......

 

We are interested in a very small group of auto engines built lightly enough to be applicable to aviation and we see here even some of those are significantly too heavy

 

The "added lightness" is the killer to reliability.

 

This extra weight is especially a problem in aircraft segments with restrictive weight limits. Another good reason for increased MTOW

 

 

[fly_tornado]

even Aeromomentum are bench testing their engines

 

 

 

[Brett]

Haha,,,nice test bench,,, pull the wrong lever,,,,prop strike!

 

 

[fly_tornado]

safety is never a big priority in america

 

 

[Paul davenport]

Arent we crossing engines stories here, the reliability of general auto engines and heavy vehicle diesels isnt what we are looking at.BUT I did have some short time with Toyota engine developers who clearly stated Australian duties were the toughest they had encountered worldwide.

Their severe test regimes involved not exceeding 60kmh off any sealed roads.......

 

We are interested in a very small group of auto engines built lightly enough to be applicable to aviation and we see here even some of those are significantly too heavy

 

The "added lightness" is the killer to reliability.

 

This extra weight is especially a problem in aircraft segments with restrictive weight limits. Another good reason for increased MTOW

Spot on JJ these engines are beautifully made and to exacting tolerances, far better than aero engines which despite their built for purpose applications still leave a lot to be desired ,not that they are bad just they could be far better than they are but economy of scale and certification of new technology’s is costly so here we sit. There is light at the end of the tunnel the experimental engines with the ignition and fuel systems is a start

 

 

[onetrack]

The problem of "testing" is that simulation of real-life operating conditions, trying to determine faults, is not the same as real-life operations.

 

The Ford video is pure marketing glitz and show, it doesn't show real-life working conditions, where owners and operators indulge in doing things that engineers and designers never envisaged.

 

Then there's the effects of corrosion and degradation in cooling systems over time - which is difficult to simulate on a test stand - but which poses a real threat to water-cooled engines. Something like 60% of engine failures are cooling-system related.

 

The smartest manufacturers produce their product and give it to potential end-users to put to work in real-life conditions.

 

Caterpillar used to be famous for giving prototypes of completely new tractors to contractors, to test out and find the faults, "on the job". However, they have stopped that process today, but their engines still develop problems.

 

The Ford/Peugeot "Puma" and "Duratorq" engines are designed with bearing shells that don't have locating tangs to prevent spinning in the block. It's a typical cheap-arse Ford, money-saving measure.

 

Of course, Ford say that there's no need for tangs, the clamping force of the cap holds the shell without any need for a tang.

 

That's all very well, until owners get slack on the oil change regime, or they use an incorrect grade or brand of oil - or they suddenly encounter a vicious and unexpected temperature change (a substantially-below-zero morning in a temperate climate).

 

The end result of these above events is excessive friction between crankshaft journal and bearing - and the bearing commences to spin in the block. Result - engine failure.

 

The simple problem with automotive engines is that they are built to a price regime - and automotive manufacturers are notorious for constantly seeking ways to shave cents off the production cost of every single component.

 

They are driven by bean counters, and 25c saving on an annual production level of say 200,000 components, equates to $50,000 pure profit, that goes straight on the bottom line.

 

GM refused to spend a reported 57 cents on an ignition switch upgrade, because it was deemed economically unacceptable - yet it ended up costing them tens of millions because the fault killed 13 people, and they had to recall 2.6M vehicles.

 

The automotive manufacturers are driven by a "low-cost" culture, the dedicated aircraft engine manufacturers are driven by a safety culture, centred around ensuring the absolute minimum possibility of failure.

 

 

[Old Koreelah]

...BUT I did have some short time with Toyota engine developers who clearly stated Australian duties were the toughest they had encountered worldwide.Their severe test regimes involved not exceeding 60kmh off any sealed roads...

(Warning: thread drift) I know of a visiting Toyota engineer being aghast to see Hiluxes and Landcruisers being driven at highway speeds. He said their design speed was 80km/h.

 

The Corolla's was 130km/h.

 

 

[Paul davenport]

The problem of "testing" is that simulation of real-life operating conditions, trying to determine faults, is not the same as real-life operations.The Ford video is pure marketing glitz and show, it doesn't show real-life working conditions, where owners and operators indulge in doing things that engineers and designers never envisaged.

Then there's the effects of corrosion and degradation in cooling systems over time - which is difficult to simulate on a test stand - but which poses a real threat to water-cooled engines. Something like 60% of engine failures are cooling-system related.

 

The smartest manufacturers produce their product and give it to potential end-users to put to work in real-life conditions.

 

Caterpillar used to be famous for giving prototypes of completely new tractors to contractors, to test out and find the faults, "on the job". However, they have stopped that process today, but their engines still develop problems.

 

The Ford/Peugeot "Puma" and "Duratorq" engines are designed with bearing shells that don't have locating tangs to prevent spinning in the block. It's a typical cheap-**** Ford, money-saving measure.

 

Of course, Ford say that there's no need for tangs, the clamping force of the cap holds the shell without any need for a tang.

 

That's all very well, until owners get slack on the oil change regime, or they use an incorrect grade or brand of oil - or they suddenly encounter a vicious and unexpected temperature change (a substantially-below-zero morning in a temperate climate).

 

The end result of these above events is excessive friction between crankshaft journal and bearing - and the bearing commences to spin in the block. Result - engine failure.

 

The simple problem with automotive engines is that they are built to a price regime - and automotive manufacturers are notorious for constantly seeking ways to shave cents off the production cost of every single component.

 

They are driven by bean counters, and 25c saving on an annual production level of say 200,000 components, equates to $50,000 pure profit, that goes straight on the bottom line.

 

GM refused to spend a reported 57 cents on an ignition switch upgrade, because it was deemed economically unacceptable - yet it ended up costing them tens of millions because the fault killed 13 people, and they had to recall 2.6M vehicles.

 

The automotive manufacturers are driven by a "low-cost" culture, the dedicated aircraft engine manufacturers are driven by a safety culture, centred around ensuring the absolute minimum possibility of failure.

Ford and GM are renown for their penny pinching antics, and to a lesser degree so are all other auto makers but the Japanese seem to pull back from this more so it than others building into their motors a reserve of strength and that is most likely the place where the weight is added

 

 

[turboplanner]

Arent we crossing engines stories here, the reliability of general auto engines and heavy vehicle diesels isnt what we are looking at.BUT I did have some short time with Toyota engine developers who clearly stated Australian duties were the toughest they had encountered worldwide.

Their severe test regimes involved not exceeding 60kmh off any sealed roads.......

 

We are interested in a very small group of auto engines built lightly enough to be applicable to aviation and we see here even some of those are significantly too heavy

 

The "added lightness" is the killer to reliability.

 

This extra weight is especially a problem in aircraft segments with restrictive weight limits. Another good reason for increased MTOW

I would have hoped people could think past the idea of putting a diesel truck engine into a recreational aircraft, or unbolting the family's Corolla engine and jamming it into a Jab.

Yes the OP's suggestion fails on weight.

 

However there are lessons to be learnt from engine design in the automotive industry. If you can get an understanding of why a 450 horsepower will last a lifetime in one application, but fail in the same application in a different district, or understand why a semi trailer carrying fuel needs smaller transmission steps than one carrying general freight, or more power when carrying stock, or a different diff ratio when operating on sand, and you can graps the effect of constant loading vs intermittent loading, and if you go from there to understanding the effect of prop diameter and pitch on the combustion temeperature of an engine in a boat or aircraft engine, you will have a better chance of making a good choice.

 

I've had a two stroke engine I could carry under one arm which pumped out 100 hp, and gave satisfactory life for the 90% load factor application, but it wasn't suitable for an aircraft application, so "added lighness" in itself is a red herring; it's the mistakes the designers make that cause the problems.

 

 

[onetrack]

I seem to recall Caterpillar had some pretty spectacular failures, trying to use their 3612 industrial/construction equipment engine, as a locomotive power plant.

 

Now, you'd think that these applications involve the same stresses - and even Caterpillar thought they did - but they came unstuck, because loco engines have substantially different and more severe stresses placed on them, than engines employed in industrial and construction equipment.

 

The same principle applies between automotive-use design engines, and aircraft-use design engines. Having a full understanding of the stresses and requirements of the particular use, is crucial for reaching satisfactory durability levels.

 

 

[turboplanner]

Ford and GM are renown for their penny pinching antics, and to a lesser degree so are all other auto makers but the Japanese seem to pull back from this more so it than others building into their motors a reserve of strength and that is most likely the place where the weight is added

At the end of WW2 the Japanese exported cheap products, primarily copies and a lot of folded sheetmetal. The quality was so be that they were universally condemned, and brought shame to the Nation. The Japanese cannot stand to be shamed, so a quality driver started until it outstripped virtually all other countries. Soichiro Honda was a parts seller and recorded his shame when his parts failed, and his driver for reliability and durability is also well documented. By the 1970's they'd put Australian car manufacturing to shame; we'd got used to the window winders falling off, sun shades breaking, hinges sagging, and every panel bolted on at a different angle in Australian cars, and our manufacturers saw the benefit of the Japanese quality control system too, and adopted it in the 1980s. We became used to buying a car, and for the most part not having to bring it back for faults. It's interesting to see the current pattern as European cars come back into the Australian market.

 

 

[coljones]

The problem of "testing" is that simulation of real-life operating conditions, trying to determine faults, is not the same as real-life operations.The Ford video is pure marketing glitz and show, it doesn't show real-life working conditions, where owners and operators indulge in doing things that engineers and designers never envisaged.

Then there's the effects of corrosion and degradation in cooling systems over time - which is difficult to simulate on a test stand - but which poses a real threat to water-cooled engines. Something like 60% of engine failures are cooling-system related.

 

The smartest manufacturers produce their product and give it to potential end-users to put to work in real-life conditions.

 

Caterpillar used to be famous for giving prototypes of completely new tractors to contractors, to test out and find the faults, "on the job". However, they have stopped that process today, but their engines still develop problems.

 

The Ford/Peugeot "Puma" and "Duratorq" engines are designed with bearing shells that don't have locating tangs to prevent spinning in the block. It's a typical cheap-**** Ford, money-saving measure.

 

Of course, Ford say that there's no need for tangs, the clamping force of the cap holds the shell without any need for a tang.

 

That's all very well, until owners get slack on the oil change regime, or they use an incorrect grade or brand of oil - or they suddenly encounter a vicious and unexpected temperature change (a substantially-below-zero morning in a temperate climate).

 

The end result of these above events is excessive friction between crankshaft journal and bearing - and the bearing commences to spin in the block. Result - engine failure.

 

The simple problem with automotive engines is that they are built to a price regime - and automotive manufacturers are notorious for constantly seeking ways to shave cents off the production cost of every single component.

 

They are driven by bean counters, and 25c saving on an annual production level of say 200,000 components, equates to $50,000 pure profit, that goes straight on the bottom line.

 

GM refused to spend a reported 57 cents on an ignition switch upgrade, because it was deemed economically unacceptable - yet it ended up costing them tens of millions because the fault killed 13 people, and they had to recall 2.6M vehicles.

 

The automotive manufacturers are driven by a "low-cost" culture, the dedicated aircraft engine manufacturers are driven by a safety culture, centred around ensuring the absolute minimum possibility of failure.

Engineers and designers are acutely aware of the stresses and strains that their products are put through. there is some beef built in to all products to cover material variability, environmental and operator extremes but at the end of the day all products need to be built to a price that satisfies the market. If people want absolute fail safe and idiot proof that is an entirely different market with an entirely different price point. Engineers and designers can build for that market but are the idiots who need this design prepared to pay for it? automotive engineers build for a fit for use market as do all engineers. what we need is a market that buys for THEIR INTENDED use.

 

 

[turboplanner]

Engineers and designers are acutely aware of the stresses and strains that their products are put through. there is some beef built in to all products to cover material variability, environmental and operator extremes but at the end of the day all products need to be built to a price that satisfies the market. If people want absolute fail safe and idiot proof that is an entirely different market with an entirely different price point. Engineers and designers can build for that market but are the idiots who need this design prepared to pay for it? automotive engineers build for a fit for use market as do all engineers. what we need is a market that buys for THEIR INTENDED use.

In that case, in the 130 hp market you could try sticking to aero engines.

 

 

[facthunter]

Tangs on a bearing won't help if the "crush" interference fit, is wrong. Failures of parts in a modern vehicle in the market are certain death for a company. Rectification is costly and your reputation is easily lost. The profit on an individual vehicle may be very little. Many models sell at a zero profit, or even a loss, but it may suit a company to test the market with small batches of "adventurous " designs. Some models have more advertising cost that the profit. Advertising is targeted. That's why many makers sponsor racing. (A very risky and costly decision) . Latest technology engines cost more than superseded concepts (copies). Some vehicles that are originally considered very reliable after a few years prove to be hand grenades and virtually unrepairable (economically). whether this is a planned obsolescence or just crook design. ( I believe it's planned). Lack of available spares for older models means you can't use them, and they go to the wreckers, although the part may be something quite simple.

 

Car engines are made for a particular market and use. They are not untended to be rebuilt (or modified) generally. For the use intended they are very suitable and cheap and perform well. I'm pretty sceptical of using them in aircraft. They may not even have suitable mounting points for a redrive or different engine mounting points to suit an aircraft . Nev