Aircraft certified motor vehicle engines. Is there a niche for them

Any engine that does short runs and rarely gets warmed up will not last long. Like a car that only goes to school or the railway station.. You don't buy those cars if you are smart. I've often purchased ex travellers cars with a quick and high mileage and all went with out engine issues for hundreds of Km's more.

In a plane, the oil has to regularly get to above 85 C (depends on where it's measured a bit). in your aircraft. engine or sludge will form. In your car engine a damaged thermostat that doesn't close will do a lot of harm. That's even more important than an oil change.. I've worked on fleet vehicles that do incredible mileages and had cars my family own get to over 600,000 Kms and still in good order.. With aircraft, school ones in those days flew most of each day and they'd go to 1200 hours and have a TOP then go to TBO. Engine failures where I was(RNAC,) were extremely rare . I can't recall one except a DH Gypsy 10 Mk 2 new that had a cracked crankshaft. (Probably been dropped) but the maintenance was good at that place..

My later experience with BIG round engines (4 at a time) had the most engine failures. Long haul mostly with about 7 in 8000 engine hours probably due to the fact they were 'tired" and far from new.. They didn't have wear problems just fatigue from having explosions going off inside for too long. Usually head failure at the shrink band but occasionally big issues where all the big bit's turn. One aircraft had over 70 thousand airframe hours. That's the life of about 30 engines. Nev

Turbo, I have heard about sparkles engine technology. I thought at one stage my vehicle may have had one. However I found spark systems. Are they for starting, what can you tell about sparkless engines. Attached images is my engine with the cover removed

Turbo, I have heard about sparkles engine technology. I thought at one stage my vehicle may have had one. However I found spark systems. Are they for starting, what can you tell about sparkless engines. Attached images is my engine with the cover removed

The first production of these is the Mazda Skyactive-X

It's called Homogenous Charge Compression Ignition (HCCI) where the mixture auti-ignites in an exothermic process.

Spark is not used to ignite the mixture but the system has its pluses and minuses compared to Otto or diesel cycle, and Mazda uses spark plus for part of the process and call it "Spark Controlled."

There is plenty on Wikipedia for the Skyactive-X, but you'd have to go to industry sites for the latest developments.

I think I can see 3 plus a bit of another spark plug actuators on yours; that's similar to the current petrol/spark plug engine.

Could somebody expand on the Otto and Diesel cycles that are being spoken of here.

I was under the impression that a diesel engine could run on the Otto cycle principle, but I know little about theory, having only been a mechanic back in the fifties.

I've always considered the OTTO cycle was the usual 4 stroke concept. There's another thermodynamic consideration called a CARNOT cycle which jet engines go by. With Highboost engines where the fuel MUST be injected or it risks detonation who cares whether there's a spark plug there or not? The efficiency won't vary as far as I can fathom once you get into the timed injection syndrome. A spark plug can easily become a glow plug also., as can an exhaust poppet valve (another risk to the engine's reliability). Fuel cannot burn until it gets there. That's what you are relying on, and that's why the octane rating no longer matters Nev

I've always considered the OTTO cycle was the usual 4 stroke concept.

Apparently with a spark plug and Diesel cycle without the spark plug.

Oh I'm so glad I get in my Lyc powered machine and turn the key then fly.... The 'kiss' method has worked for longer than most here have been on the planet!?? I do the one thing that these engines love, being used!?

They are still the best way to go IF you don't just wish to make your own engine where you will certainly do LESS flying. The lycoming is a proven entity even if the fours are klunkers at least they aren't revving like they are going to fly apart. and little screws want to undo. Maybe some feel the need to fly less than others. Some engines have character (certainly Jet ones don't except they DO make some great noises at just the right speeds if they are big enough to fit a van into the front of them). The ordinary Joe couldn't think of being able to afford one. Bang for your bucks is what most of us have to weigh up. realistically. You don't fly recflying to get to places . You do it because you like flying and aeroplanes and use going somewhere as an excuse. Nev

You don't fly recflying to get to places . You do it because you like flying and aeroplanes and use going somewhere as an excuse. Nev

Interesting that a lot of people who have had problems were flying places as if they were using cross-country aircraft.

Proper Planning Prevents Piss Poor Performance. If you are paid to fly you fly anytime. IF you fly for fun you fly when you decide it's best. Nev

Proper Planning Prevents Piss Poor Performance. If you are paid to fly you fly anytime. IF you fly for fun you fly when you decide it's best. Nev

That's exactly what I do. These days I fly when I want to fly, to hell with sched's, TS's and MEL's??

Toyota Patent Suggests a High-Compression Diesel Truck Engine May Be in the Works

Toyota look like they are developing a high efficiency engine. Toyota Supra already use a dual cycle BMW engine. 40% efficiency announced in the article is huge. Best Otto cycle engine efficiency available is around 30%. Increasing the range of an aircraft or better still free some aircraft weight up for other purposes.

I just read the sales blurb for the new BMW R1250 Boxer engine. Apparently variable valve timing has led to an increase in "sovereignty".

So, take a big displacement motorcycle engine that already needed a bunch of electronics to keep the operator safe from themselves and ... and ... add more complexity? Ugh!

Maybe we're going down the wrong path:

https://www.theguardian.com/environment/2020/jul/13/andean-condor-fly-without-flapping-wings-flight-bird

Yes don't go near those damed fangled flying machines, the good old horse for me ?

Maybe we're going down the wrong path:

 

https://www.theguardian.com/environment/2020/jul/13/andean-condor-fly-without-flapping-wings-flight-bird

We already have that sort of thing. If it's your cup of tea, there are still gliding clubs around. Get yourself a terry towelling hat and some elastic waisted slacks and head on down.

You forgot the zinc cream for the nose.

And a "This is MY thermal- Bugger off." sign.. Nev

Seemed to be a very select tribe. ( A little hard to get an invite )

spacesailor

Seemed to be a very select tribe. ( A little hard to get an invite )

spacesailor

We already have that sort of thing. If it's your cup of tea, there are still gliding clubs around. Get yourself a terry towelling hat and some elastic waisted slacks and head on down.

We already have that sort of thing. If it's your cup of tea, there are still gliding clubs around. Get yourself a terry towelling hat and some elastic waisted slacks and head on down.

Have some respect for our gliding friends we all share the same airspace we should all train in gliders first

I just read the sales blurb for the new BMW R1250 Boxer engine. Apparently variable valve timing has led to an increase in "sovereignty".

 

So, take a big displacement motorcycle engine that already needed a bunch of electronics to keep the operator safe from themselves and ... and ... add more complexity? Ugh!

Use a BMW HP2 Enduro engine, 107 hp and blueprinted from factory :-)

Yes don't go near those damed fangled flying machines, the good old horse for me ?

Until it falls down a hole, breaks a leg......then rolls on top of you?

Have some respect for our gliding friends we all share the same airspace we should all train in gliders first

Nothing wrong with a bit of friendly rivalry....

Until it falls down a hole, breaks a leg......then rolls on top of you?

Or spooks at a.....well pretty much anything and runs out in front of a truck

And a "This is MY thermal- Bugger off." sign.. Nev

It doesn't work that way Nev...Thermals are community property. So I'm told