Wankel/rotary - why dont we see more in experimental aircraft ?

[spenaroo]

Yeah but the weight is also increasing along with the complexity. Those 2lt utes aren't simple single turbo, it's all bi turbo now. But they have limitations especially with the emissions crap Needing to DPF burn. They also have shorter engine life's.

[facthunter]

The engine reco business is dead. Bi turbo is not for power (except on some vee engines) .It's to stop turbo lag. They have also upped oil drain periods.. Most failures are low coolant or servicing . By and large they aren't unreliable.  You never pull the heads off them. Most people don't know where the dipstick is or what it's for (IF there is one.). Nev

[onetrack]

The 2 litre bi-turbo engines are useless when it comes to real work. They have to scream to produce the power, they can't produce real grunt - solid torque at low RPM - like the bigger capacity diesels do.

I doubt very much whether they will have the same lifespan as the bigger capacity engines. I've seen Landcruiser 4.5L V8 diesels with 800 and 900,000kms on the clock, and still purring.

The Landcruisers will go through 3 suspension overhauls in that period, but they never touch the engine. The bi-turbo 2 litre engines are complex, and they need two turbos to pump the volume of air in, to get the HP/Kw.

On top of that, the 2 litre bi-turbo diesels are thirstier than the bigger capacity diesels producing the same HP/Kw. 

That's because diesel is a slow-burning fuel, and once you go over 3000RPM with a diesel, a lot of fuel is going out the exhaust, improperly combusted.

 

 

Edited June 12, 2021 by onetrack

[facthunter]

The torque they have comes in at very low rpm. and economy is the reason they are low displacement. The most powerful Ranger is the small engined one. I still think (a bit) like you but it's happening out there. Fuel is much dearer than here in most places.. Nev

[spenaroo]

23 minutes ago, facthunter said:

The engine reco business is dead. Bi turbo is not for power (except on some vee engines) .It's to stop turbo lag. They have also upped oil drain periods.. Most failures are low coolant or servicing . By and large they aren't unreliable.  You never pull the heads off them. Most people don't know where the dipstick is or what it's for (IF there is one.). Nev

You never pull the head off of them because of the expense. After 300k something fails and it's easier to just drop another motor in. Seen it a few times. Water pump fails - new motor. Timing belt failure - new motor. They just aren't economical to rebuild.

[facthunter]

Nothing is these days. In some $#!t designs S/H motors are through the roof in price because it has a chronic fault.  Plenty leave the timing belt to run way over the specified time. Of course the motor is ruined that's always been the case with any diesel and also a few petrol motors. A high output motor will damage quicker if something goes wrong . Do you want us to go back to Gardiner Diesels with babbit bearings?  Diesels used to hold people up on hills and cover them with soot  Not the case these days. Nev