There Is A Lesson Here

[1001001]

17 hours ago, GeeBee said:

...

Why are we building 1930's engines with split cases? Why don't we have have mono block cases with the cylinders bolted on such that removal of the cylinder does not threaten to compromise the main bearing assembly? We continue to struggle with air cooled engines when the benefits of liquid cooling are well known and engine technology has advanced to create light weight aluminum blocks. Go back to 1963 and GM created an aluminum V-8 that weight about the same as an O-320. 
 

...

 

This is where the future of aviation engines is, IMO.  I don't know if they're going for certification, but in the experimental market, there is great promise.

They have a rather complete line of products they are working on, including water cooled mono block cylinders that bolt on to Lycoming engines and save weight, and the big one:  a spark ignition water cooled V-4 combined cycle "Higgs Diesel" that will run on Jet A OR 100LL if needed.  The version for the RV-10 adds 90 hp and drops 100 lb of weight including the liquid cooling system vs the standard IO-540-D4A5.

Edited November 30, 2020 by 1001001

[aviatoreb]

2 hours ago, GeeBee said:

I'm searching for reliability, efficiency and ease of operation. Our internal combustion engines in aviation compared to other modes are lacking. I can drive my car from from the Jersey shore to Pike's peak and never touch a mixture knob, and it starts in a split second in both places. Not only that, the mixture is always "on the money". If detonation were to start, in a fraction of a second it is stopped. If it looses coolant it "limps" home. Hundreds of miles if needed. It is 6 cylinders and puts out 382 hp. Power to weight ratio? Got it in spades. 

 

Don't be so sure.  I bet you can but not all cars can drive Pike's Peak.  I bet your car can, but not all can.

When I was in school at UC Boulder, we went down to drive Pike's Peak for fun just to do it.  My car was not able to make it to the top.  I had a 1979 Mazda RX7 which was a fun little car with a Wankel rotary engine. Anyway maybe 3/4 of the way up on a steep section my car just kept stalling.  It did not have enough power anymore to keep heading up hill even in the smallest gear.  I had to literally back up with engine off to point down hill.

There's a cool car race that goes up Pikes Peak with light weight rally-style highly turbo charged cars.

[steingar]

Skyhawk prices are nuts, both for rentals and for sale.  Lots of flight schools want them, as well as everyone else.  I watched the guys in the hangar across from me buy a Skyhawk with an 0360, it cost more than my Mooney, burned more gas, slew slower, had horrible cosmetics and no panel. There are aircraft that can be had for less money, Skyhawks just aren't one of them.

[tmo]

32 minutes ago, steingar said:

Skyhawk prices are nuts

All around the world it seems - people two hangars down from where I park sold a run-out C172 and without adding any money bought a C182 with quite some time on the engine, and similarly equipped (G1000, WAAS).

[McMooney]

seriously, it all comes down to MONEY.  

100% sure an engine can and has been adapted but at the end of the day, it has to be profitable and affordable.

Best bet would be to sweet talk Diamond into sharing those nice Austero Diesels, i'd def put one in the mooney if it was about the same cost as the lyco

 

 

[tmo]

I don't think Diamond has nothing to say about who Austro sell their engine to...

[GeeBee]

6 hours ago, aviatoreb said:

Don't be so sure.  I bet you can but not all cars can drive Pike's Peak.  I bet your car can, but not all can.

When I was in school at UC Boulder, we went down to drive Pike's Peak for fun just to do it.  My car was not able to make it to the top.  I had a 1979 Mazda RX7 which was a fun little car with a Wankel rotary engine. Anyway maybe 3/4 of the way up on a steep section my car just kept stalling.  It did not have enough power anymore to keep heading up hill even in the smallest gear.  I had to literally back up with engine off to point down hill.

There's a cool car race that goes up Pikes Peak with light weight rally-style highly turbo charged cars.

The point is this. In 1979 you did not have FADEC. However now you do. It is a 30 year old tech on recips that shows unbelievable reliability. I own 4 cars, one of them as old as 2002, two of them diesels and not one of them has a throttle cable. They are all FADECs. Yet.....no FADEC for our engines. We're still moving mixture knobs and glassy eyed at EGTs.

[aviatoreb]

29 minutes ago, GeeBee said:

The point is this. In 1979 you did not have FADEC. However now you do. It is a 30 year old tech on recips that shows unbelievable reliability. I own 4 cars, one of them as old as 2002, two of them diesels and not one of them has a throttle cable. They are all FADECs. Yet.....no FADEC for our engines. We're still moving mixture knobs and glassy eyed at EGTs.

I agree.

Would just about any modern car whatsoever make it up Pike's peak?

I remember when I was 16 my parents owned a Volkswagen rabbit diesel.  That thing was a little beast.  It belched black soot.  It had horrible power.   It was in Maryland and no kidding you could not run the airconditioner while driving up a steep hill.  You would need to turn the airconditioner lever to off during a steep (little) climb if you didn't want to down shift (manual) to first gear. It was fun.

[Andy95W]

34 minutes ago, GeeBee said:

The point is this. In 1979 you did not have FADEC. However now you do. It is a 30 year old tech on recips that shows unbelievable reliability. I own 4 cars, one of them as old as 2002, two of them diesels and not one of them has a throttle cable. They are all FADECs. Yet.....no FADEC for our engines. We're still moving mixture knobs and glassy eyed at EGTs.

The point is this.  Our engines do a remarkably efficient and reliable job of producing 65-80% power for 2000 hours.  Could you gain a few percentage points here or there of efficiency? Sure.  But why would you spend $50-100k to gain a few percentage points?

And as Rich pointed out above, lots of people have been talking about and proposing these same ideas for decades.  Is it possible that they are all idiots and too stupid to bring them to fruition?  Not likely.

And we regurgitate these same discussions regularly, most recently last April.

 

[GeeBee]

65 to 80% power at what? 2400 RPM? In those 2000 hours you will likely change the oil at least 40 times, IRAN the ignition 4 times at least, likely go through one set or nearly so of cylinders and pistons at a cost of about 4K per jug.

2000 hours on a car at 60 mph is about 120,000 miles. In that time on my car I will have to change the plugs AT 120K. Pistons and cylinders will still be good and change the oil about 12 times. The engine will easily go 250,000 or 4000 hours in airplane terms.

You and I both know what is needed here, unleaded fuel, continuous lean burn, FADEC and liquid cooling. There is no reason why we cannot have it except those wedded to "good enough".

 

[aviatoreb]

1 hour ago, Andy95W said:

The point is this.  Our engines do a remarkably efficient and reliable job of producing 65-80% power for 2000 hours.  Could you gain a few percentage points here or there of efficiency? Sure.  But why would you spend $50-100k to gain a few percentage points?

And as Rich pointed out above, lots of people have been talking about and proposing these same ideas for decades.  Is it possible that they are all idiots and too stupid to bring them to fruition?  Not likely.

And we regurgitate these same discussions regularly, most recently last April.

 

60-80% of what?  Of a made up number that is called 100% where it is considered safe to run the thing at 80% for prolonged periods relative to that 100%.  My same engine a TSIO520 can be tricked out to go 200% for short runs as a reno racer.  Or in my application it is called 100% at 305hp.  Or in a Cessna 414 some ratings have it at 335hp.

My Subaru WRX STI that I had for 17 years (just sold it in April) was rated to 300hp on a 150cu engine which is much much smaller than a 520.  Obviously.  Sure it was an entirely different material and build.  But separate, that 300hp is or 0-60 mph fun advertising and selling cars.  (Current they advertise 0-60 in 5.3 sec).  Don't be driving around at 300hp for hours on end.  It will over heat.  just ask anyone who suffered through the subaru-eggenfeller aircraft conversion where they are reputed to terribly overheat at well less than 50% of that 300hp rating for continuous use.

[Andy95W]

58 minutes ago, GeeBee said:

 

2000 hours on a car at 60 mph is about 120,000 miles. In that time on my car I will have to change the plugs AT 120K. Pistons and cylinders will still be good and change the oil about 12 times. The engine will easily go 250,000 or 4000 hours in airplane terms.

You and I both know what is needed here, unleaded fuel, continuous lean burn, FADEC and liquid cooling. There is no reason why we cannot have it except those wedded to "good enough".

 

I always love it when people point out the 60 mph/2000 hour car comparison.  Fact is, your car engine at 60 mph is loafing at about 25% power.  When you can run your car at 120 mph for 2000 hours I’ll listen.

As far as unleaded fuel, FADEC, liquid cooling, etc., you’ll get no argument from me.  But it raises a good question: 

After decades of electronic ignition, electronic fuel injection, and computer controlled car engines, why are guys building brand new RVs putting Lycomings in them?  Are you seriously suggesting that those Experimental builders are also wedded to “good enough”?

[GeeBee]

They are wedded to what the airframe was designed around.

To do some other power plant would require new mount, cowling etc. I don't think a lot of kit builders are down for that.

 

 

 

[Yetti]

Engine RPM.    Looks like they have a gear driven PRU.  So that is good.  Diesel is good because the RPMs match Propeller RPMs.   They are bad because you need lots of heavy cast iron.

[1001001]

2 hours ago, Andy95W said:

...

After decades of electronic ignition, electronic fuel injection, and computer controlled car engines, why are guys building brand new RVs putting Lycomings in them?  Are you seriously suggesting that those Experimental builders are also wedded to “good enough”?

We may be putting Lycomings in them, but most people building RVs are going for the best tech we can get to put on those engines.  We're not stuck with whatever was certified 40 years ago.  Electronic ignitions, great new fuel injection systems, open-, and in some cases, closed-loop mixture control with O2 sensors -- mostly people running mogas, but there are some reports that there is at least one brand of O2 sensor that can handle 100LL. 

Once we get real unleaded fuel that can match vapor pressures etc. with avgas, things will get even better.

Lycomings aren't bad engines, and they can be made into great engines by adding new tech to them.  The best stuff coming down the road, however, is things like what I posted up above--the Higgs Diesel, liquid cooled cylinders for Lycomings that will improve cooling and help detonation margins and prolong cylinder life due to better temperature control--heck, actual closed loop temperature control will allow better tolerances in the cylinders and make the engines more efficient and more stingy with oil burns.

There are good reasons that Lycomings are still used, and one of the big ones is PSRUs.  Almost every auto engine conversion out there needs a PSRU, and there aren't too many good ones out there.  What you need is not an engine, but a powerplant package. 

[1001001]

7 minutes ago, Yetti said:

Engine RPM.    Looks like they have a gear driven PRU.  So that is good.  Diesel is good because the RPMs match Propeller RPMs.   They are bad because you need lots of heavy cast iron.

Not necessarily.  The Higgs combined cycle engines are pretty lightweight compared even to air cooled Lycomings.  It'll be good to get a few of those airborne in the RV fleet and really wring them out.  The UAV market will be an important one for testing those out, too.

[Yetti]

1 minute ago, 1001001 said:

Not necessarily.  The Higgs combined cycle engines are pretty lightweight compared even to air cooled Lycomings.  It'll be good to get a few of those airborne in the RV fleet and really wring them out.  The UAV market will be an important one for testing those out, too.

Ok 73.   Not sure why but the old Briggs and Strattons were designed to run at 1800 RPM and the new are designed to run at 3600.   I always wonder why the change in RPM and what it would take to make say an LS2 run at lower RPM.

[RLCarter]

My hangar neighbor has an RV12 with a Honda Fit engine, laying on it side no less. I have no problem with what we have, somewhat. Cam lobes doing double duty while others aren’t, bearings/cases that won’t stay put when cylinders are removed, sealants that my grandfather used (I’m 60), oils & engines for that matter that need additives so cams/lifters don’t fail if it sits more than a month, the list goes on. Our engines while fairly reliable are junky compared to other engines even from the 80’s, hell the little V6 in my truck puts out 375hp and I paid less for my truck than it would cost me for a new IO-360. 

[N201MKTurbo]

8 hours ago, RLCarter said:

My hangar neighbor has an RV12 with a Honda Fit engine, laying on it side no less. I have no problem with what we have, somewhat. Cam lobes doing double duty while others aren’t, bearings/cases that won’t stay put when cylinders are removed, sealants that my grandfather used (I’m 60), oils & engines for that matter that need additives so cams/lifters don’t fail if it sits more than a month, the list goes on. Our engines while fairly reliable are junky compared to other engines even from the 80’s, hell the little V6 in my truck puts out 375hp and I paid less for my truck than it would cost me for a new IO-360. 

Your truck engine has probably never made anywhere close to 375 HP, If it did it was only for a few seconds. If you asked it to make it continuously, It would overheat in short order. To make that power, you need to run it at WOT and redline RPM at sea level. A hard combination to make, you would need to tow a heavy trailer in low gear with your foot to the floor and the engine screaming like crazy. Yet, we ask our engines to make full power on every takeoff. Our engines are certified to make 100% power continuously without overheating.

[tmo]

10 hours ago, Yetti said:

Diesel is good because the RPMs match Propeller RPMs

Actually, most, if not all aviation diesel engines have a gearbox. As do the Rotax ones.

[Yetti]

25 minutes ago, N201MKTurbo said:

Your truck engine has probably never made anywhere close to 375 HP, If it did it was only for a few seconds. If you asked it to make it continuously, It would overheat in short order. To make that power, you need to run it at WOT and redline RPM at sea level. A hard combination to make, you would need to tow a heavy trailer in low gear with your foot to the floor and the engine screaming like crazy. Yet, we ask our engines to make full power on every takeoff. Our engines are certified to make 100% power continuously without overheating.

but at lower rpm with direct drive.   So what would it take to get a modern engine to run at lower rpm?  does it make half the horsepower?

[GeeBee]

11 hours ago, 1001001 said:

Lycomings aren't bad engines, and they can be made into great engines by adding new tech to them.  The best stuff coming down the road, however, is things like what I posted up above--the Higgs Diesel, liquid cooled cylinders for Lycomings that will improve cooling and help detonation margins and prolong cylinder life due to better temperature control--heck, actual closed loop temperature control will allow better tolerances in the cylinders and make the engines more efficient and more stingy with oil burns.

Now you are saying what I believe.

 

[N201MKTurbo]

Just now, Yetti said:

but at lower rpm with direct drive.   So what would it take to get a modern engine to run at lower rpm?  does it make half the horsepower?

If you put a prop and governor on it and regulate it to 2700 RPM that is the fastest it will turn. All engines have a HP curve that increases with RPM. After all power is work (torque) over time (RPM). Reducing the RPM will reduce the HP linearly if the torque is constant, which it isn't, but not far from it. So if you cut the RPMs in half the HP will be cut in half. The 375 HP truck engine is probably rated at ~6000 RPM If you cut the RPMs to 2700, the power drops to 169 HP. That is why most automotive conversions have a gearbox so the engines can run at higher RPMs and make more HP. If you put a gearbox on our IO-360s you could probably get over 300HP out of it. You probably couldn't keep the CHTs in check at that power, but it would make it for a bit, just like automobile engines will only make their rated HP for a bit.

[GeeBee]

I've driven a good number of Mercedes and Audi's pedal to the metal, wide open for a good amount of time.

 

[N201MKTurbo]

2 minutes ago, GeeBee said:

Now you are saying what I believe.

 

Yes, you can add modern fuel injection and ignition to our engines, but it doesn't bring much to the table. We operate our engines in a very narrow RPM range and cruise at about the same RPM and MP every time. The timing is already optimized for those conditions. electronic ignition will probably be more reliable, but it won't change the power or fuel economy by much if any. The electronic fuel injection will just automatically do what we do already. It can't do anything we are aren't already doing. 

Our high performance engines (IO-360) could be run on mogas if we retarded the timing, but they wouldn't make 200 HP and there is no electronic magic that will change the physics of that.

The main thing electronic engine controls bring to the table is easier starting, which would be nice.