C172 Still In Production After 60 Years.

[onetrack]

I note that the Japanese CAB is now on a course to investigate making light aircraft safer, after a recent spike in light aircraft accidents in Japan.
They are going to examine the potential of the fitment of (cheaper) CVR's and FDR's to light aircraft - as well as looking at the potential of fitting airbags to same.
As many light aircraft crashes are quite often relatively low speed crashes, perhaps airbags in light aircraft do have some life-saving potential.
I trust the Japanese proceed with their ideas, they are very good at perfecting others ideas, or transferring technology from other fields to additional uses.
Maybe they could go the whole hog, and upgrade the 172 to some current cutting-edge technology, while they miniaturise everything at the same time!

[tartare]

Dart - I thought it was the Bell 206B?
Slow, solid and when you hit something, everything flies outwards.

[27/09]

onetrack: be 30% more fuel efficient

Using BSFC figures, can you point me to any motor vehicle engines that are 30% more efficient than an aircraft engine? Actually even finding some that are more than 15% will probably do.

As for the use of composites and robots. The composite aircraft I know of like the Diamonds are heavy suckers for their size when compared to a metal aircraft. I'm sure robots would have been in use by now if there was an advantage to be had from using them.

The aircraft manufacturing market is only a minute fraction of the size of the automotive market. There isn't enough economy of scale for automation.

[cattletruck]

What's a brand new Cessna 172 or Cherokee PA-28 cost in Australia? Last time I checked it was a big scary number. As a so called "proven" design I would have thought it be a lot cheaper by now, but they've gone and added that poxy glass cockpit which probably accounts for more cost than the engine and airframe combined to pay for all those software engineers. I wonder how much these simple planes would really cost without all that electronic jazz.

[onetrack]

Using BSFC figures, can you point me to any motor vehicle engines that are 30% more efficient than an aircraft engine?

27/09 - I was actually referring to a 30% fuel efficiency gain over the last 60 years in automotive engines - which has been driven by legislation, not by any effort on the part of auto manufacturers.
The legislation was more than likely driven by the understanding that the corporate inertia to introduce improved engine efficiency was unlikely to be overcome without legislation, when you have auto manufacturers and oil companies sharing directors on the company boards - as is, and has long been, the case.

[Traffic_Is_Er_Was]

They only sell about 150 a year, that's why they're a quarter of a mill.

[27/09]

onetrack

Had you ever considered that the current crop of avgas burning aero engines may well have always been as efficient as you can make a a petrol engine. There were no appreciable gains to be made.

Have you every noticed how almost every automobile to aero conversion has been so totally unsuccessful?

Perhaps the current crop of aero engines isn't so bad after all.

I suspect much of the automobile gains have been in technology gains with respect to the whole motor vehicle, i.e.some engine improvements along with gearbox and drive train improvements, weight reductions, more aerodynamic shapes etc.

It's pretty hard to make significant gains with your average present day aircraft. Physics dictates the shape/size etc.

[Band a Lot]

A254 cu in (4.2 L) version of the L-6 (designated the M-series orRouge 254) was used from 1948 to 1953 in F6-seriesFord trucks (COE, Dump, semi-, etc.), and small Ford school buses. The M-seriesengine produced 115 hp (86 kW) and 212 lb·ft (287 N·m). oftorque. They were also used in miscellaneous industrial applications. e.g., topower water pumps for irrigation purposes and within wine-producing farms tomanage risk by powering giant frost-control propellers on stands in the middleof rows of grapes.
The Barra 195 is the last version of the naturally aspirated I6 engineand is in the Ford FG Falcon sedan and ute (the BF Falcon MkIIIwagon and Ford Territory SY and SY II SUV and Territory SZ RWD Petrol use theBarra 190 engine). Modifications made to the engine include a revised plasticinlet manifold on naturally aspirated models and new cylinder head, whichachieved minor power and economy improvements over the Barra 190.
Power:195 kW (261 hp) @ 6000 rpm
Torque:391 N·m (288 lb·ft) @ 3250 rpm


-------------------------------------------------------------------------------

These are"engine" figures!

If we runthe Barra 195 @ 75% of the 1948 254 cu in engine, I will bet the Barra will beusing much more than 70% less of the 254. At a guess only I would happily say1/2 the fuel.

So an IO-360of old at same trend of auto needing 160 hp, could be smaller, thus lighter andthat also reduces required hp. You would be looking at an engine of about 190cubic inches (maybe a 2 cylinder) for same fuel burn or better.

Horse power = Fuel
Engine efficiencyreduces fuel burn for a given horse power, but generally fuel burn is kept thesame to have a greater horsepower available.

[onetrack]

27/09 - True, there have been efficiency gains in automobiles, with "gearbox and drive train improvements, weight reductions, more aerodynamic shapes, etc."
However, there have been pure fuel efficiency gains in auto engines, to the order of around up to 50% in the last 40 years alone.

Not surprisingly, the affluence of Western nations has seen these gains negated, as auto buyers have elected to buy heavier vehicles such as 4WD's, pickups and SUV's in vastly increased numbers in the last 25 years.
In addition, those more affluent Westerners have also demanded a lot more luxury accessories such as high quality onboard entertainment and communication systems, luxurious interiors, more safety features such as multiple airbags, "luxury" accessories such as climate control, electric windows all round, heavier multi-speed transmissions (GM's latest offering is a 10 speed automatic), and a host of other add-ons that all increase weight and impact on fuel efficiency.

In addition, many of the latest emission control devices on low-emission engines, have incurred fuel efficiency penalties as the emission devices such as EGR work against fuel efficiency.

Car and driver.com (2006) - Why gas mileage hasn't improved in 25 years

We still look to the racing field to provide substantial efficiency improvements, as a means for power output increases. However, many racing developments have spin-off potential for improved fuel efficiency in ordinary autos.

Arstechnica.com - 2016/05 - Turbulent times for Formula 1 engines results in unprecedented (engine) efficiency gains (excuse the excruciatingly simplistic technology descriptions)

[27/09]

Onetrack

You've sidestepped my original question. How does the modern automobile engine fuel consumption in BSFC compare to a Lycoming or Continental?

[Jabawocky]

How many auto engines (petrol jobbies), have a 200-260 HP output at 2500 RPM with a BSFC of around 0.39-0.395 and equal or less drag in an airframe?

And do not start on diesels, despite the 172, the 182 was a great example of why not. Very few people know why it was canned....Textron do not talk about it. A small number of us do. If I was textron i would have canned the idea too.

So, who has some real world data on auto engines with better fuel burns? I have data from a few that have done it, but it does not come anywhere near 0.395 and is north of 0.45.

Be interesting to see if anyone had achieved it.

PS: C172 with an IO360 is hard to beat for its class.

[Pinky the pilot]

Someone once pointed out to me that there are not too many auto engines that can run at red line RPM for a significant time followed by being reduced to 75% power for the cruise time.

A bit simplistic perhaps but.....

[Band a Lot]

A 172 with 200-260 hp now that's a machine of note!

[Band a Lot]

Yes pinky I used "If we runthe Barra 195 @ 75%"

Here is one of the most powerful auto engines, maybe aviation development needed a reduction drive phase (not part of engine) to utilize non aviation engine developments to an aviation advantage.

https://www.quora.com/Why-does-a-Bug...00+-horsepower

[Left 270]

When was the last time someone bought a new car with magnetos and a low pressure fuel injection system let alone a carburettor?

There have been huge gains in economy in autos (ild hate to be running a 308 like my first car now, would cost a fortune) but unless we change our thinking and use electronic timing, high compression and reduction drives not much is transferable to aviation, and reductions could never work that's what turbines never took off....

[onetrack]

27/09 - Well, without getting into an extended argument and providing reams of individual engine tests and lengthy scientific examination - Wikipedia provides some basic figures that show a Lycoming O-320 at 0.460 BSFC (29.3% energy efficiency); and a Toyota (Prius) 1NZ-FXE at 0.0370 BSFC (36.4% energy efficiency) - a difference of nearly 25% in efficiency with the Toyota engine.

I don't know how you can expect an engine that has had virtually no engineering development/advances in technology since its inception in the early 1950's, to seriously compete with a modern automobile engine that utilises a wide range of efficiency improvements in its design - such as high-tech fuel injection systems, VVT-i, multiple OHC's, low-friction rings and pistons, high compression ratios, CGI and high-tech alloys in blocks and heads, fractured metal caps for bearings, sintered iron powder for conrods. The Lyco is a dinosaur.

https://en.wikipedia.org/wiki/Brake_...el_consumption

[Sunfish]

Onetrack:

Using BSFC figures, can you point me to any motor vehicle engines that are 30% more efficient than an aircraft engine?
27/09 - I was actually referring to a 30% fuel efficiency gain over the last 60 years in automotive engines - which has been driven by legislation, not by any effort on the part of auto manufacturers.
The legislation was more than likely driven by the understanding that the corporate inertia to introduce improved engine efficiency was unlikely to be overcome without legislation, when you have auto manufacturers and oil companies sharing directors on the company boards - as is, and has long been, the case....

......I don't know how you can expect an engine that has had virtually no engineering development/advances in technology since its inception in the early 1950's, to seriously compete with a modern automobile engine that utilises a wide range of efficiency improvements in its design - such as high-tech fuel injection systems, VVT-i, multiple OHC's, low-friction rings and pistons, high compression ratios, CGI and high-tech alloys in blocks and heads, fractured metal caps for bearings, sintered iron powder for conrods. The Lyco is a dinosaur.

Onetrack. You are talking complete and utter bollocks.

You do not understand the concept of the duty cycle of an engine - the spectrum of torque and rpm over which the engine is expected to operate. An engine designed for automotive use has a completely different duty cycle to an aircraft engine and many of the automotive "developments" you speak of have no useful application to aircraft engines and they are heavy as well.

Variable valve timing and overhead cams for example have no relevance to a direct drive engine that is going to spend its entire life at 55% + of full power at 2500 rpm.

Manufacturing techniques such as fractured bearing caps, etc. may be relevant if they are amenable to quality control and reliability and maintainability considerations.

As for fuel injection, I am deeply involved in the process of commissioning an aircraft with a Rotax fuel injected engine for an alleged fuel economy increase of around 10%. I can assure you that the installation is neither cheap nor simple because of the complexities of ensuring an uninterruptible high pressure fuel flow and that relies on an uninteruptable electrical system. The engine is heavier than a carbureted engine as well.

The engine has two alternators, two ECUs, eight injectors, a raft of sensors (knock, MAP, temperature, etc) and a raft of built in logic devices to provide fail-over and alerting. It is not a trivial exercise to wire and plumb this thing.

[Tee Emm]

I wonder how much these simple planes would really cost without all that electronic jazz.

With the plethora of EFIS electronic cockpits into the Cessna and Piper population, is it any wonder that automation dependency is brain washed into student pilots at such an early stage of their career.

[onetrack]

Sunfish, I fully understand the principle of duty cycle, as I was deeply involved with heavy-duty engines for the best part of my working life. I was not inferring that automotive engines can be instantly and quickly transferred to aircraft use.
I am fully aware of the major differences in duty cycle and reliability requirements between automotive engines and aircraft engines.
What I am getting at is that old-established aircraft engine manufacturers have a vested interest in keeping archaic production lines and design principles in permanent use, as they have amortised the cost of those production facilities and designs long ago, and they are a permanent cash cow for them.
Corporate America, in particular, is permanently intent on promoting shareholder and corporate wealth, over any progress in efficiency or cost reduction to the end-users of their products.
There is no reason why the engineering advances in automotive engines cannot be engineered into aircraft engines, along with numerous other sound and progressive ideas such as rotary or sleeve valves, using current high technology.
For Gods sake man, engines are still using poppet valves, the shortest life, worst and weakest part of any IC engine design, and it's the same valve design as used in the 1890's!!
If ULPower engines can produce a modernised Lyco, utilising a number of automotive technologies, then it shows what can be done.

[27/09]

onetrack

You seem to be a trifle selective when quoting the specs on the Toyota (Prius) 1NZ-FXE engine.

From that fountain of "undisputed" information - Wikipedia:

The net result is that the engine has a greater effective expansion than compression—making it a simulated Atkinson cycle, rather than a conventional Otto cycle.

The reduction in cylinder charge means reduced torque and power output, but efficiency is increased. This combination makes the 1NZ-FXE suitable for use with the Hybrid Synergy Drive, where peak torque and power are of less importance.

Probably not a suitable engine technology for use in an aircraft.