Technology Today vs the 1960 Mooney Design

[cliffy]

Maybe I'm wrong but?

We take a 400+ HP engine (LS3 in just ONE form of supply from GM as a "crate" engine) and "de-rate" it to MAX output of 300 HP we have and engine running at 75% rated power (could be done by just picking a set MAX RPM in the HP/Torque curve. 

If we further take it to 7500 feet we lose an additional 25% of the 300 HP (NA engine) so we are cruising at 225 HP which would be 56% of the original HP rating.

So MAX Continuous would be 300 HP (75% power of the original rating) and Normal output would be about 225 HP (56% for most flying)

Are we saying that the engine can't produce this output effectively for hours on end?  It would be interesting to put one on a dyno and see.

Would this be considered running for hours at MAX HP?

Would we still be fighting such a heat rejection issue as we would at 400+HP (water and oil)?

North American figured how to get cooling drag into cooling "push" with the correct design of the P-51 belly radiator. Ram air provides usable pressure for cooling far above electric fans.

I read some where that WWII fighters were designed for a life of 400 hrs. They were throw away airplanes in time of war. Expendable commodities along with the pilots 

Just food for thought

[Blue on Top]

@cliffy  Exactly.

[GeeBee]

47 minutes ago, cliffy said:

Maybe I'm wrong but?

We take a 400+ HP engine (LS3 in just ONE form of supply from GM as a "crate" engine) and "de-rate" it to MAX output of 300 HP we have and engine running at 75% rated power (could be done by just picking a set MAX RPM in the HP/Torque curve. 

If we further take it to 7500 feet we lose an additional 25% of the 300 HP (NA engine) so we are cruising at 225 HP which would be 56% of the original HP rating.

So MAX Continuous would be 300 HP (75% power of the original rating) and Normal output would be about 225 HP (56% for most flying)

Are we saying that the engine can't produce this output effectively for hours on end?  It would be interesting to put one on a dyno and see.

Would this be considered running for hours at MAX HP?

Would we still be fighting such a heat rejection issue as we would at 400+HP (water and oil)?

North American figured how to get cooling drag into cooling "push" with the correct design of the P-51 belly radiator. Ram air provides usable pressure for cooling far above electric fans.

I read some where that WWII fighters were designed for a life of 400 hrs. They were throw away airplanes in time of war. Expendable commodities along with the pilots 

Just food for thought

Actually we do it every day in marine use. I have two 454 (7.3L) MPI GM blocks (300hp) that run all the time for hours at 3800-4000 rpm which means they are at 75 to 80% power. They do so dependably. Over 800 hours so far with no issues. I know of the same engine on a tow boat that has over 2500 hours on it and obviously is run very hard in commercial use.

 

[RobertGary1]

My GM 4.3L marine engine runs reliably but it’s crazy heavy and has an endless supply of coolant. 

[N201MKTurbo]

This whole 100% power thing needs a little more context.

I believe with regard to aircraft engines the 100% power level is the maximum power that the engine is certified to run at continuously. There are show planes that will take something like an IO-360, put on a shorter prop and run at 3500 RPM. I hear you can get almost 300HP out of one doing that, but they don't last long.

Car engines are rated at the maximum HP that you can get out of them on a dyno under operating conditions that are almost impossible to sustain by a normal driver in any normal driving situation. And if you could make your car or truck make full power continuously, it would overheat in short order. 

Marine engines are rated like aircraft engines. Their rated power is the maximum continuous power they can make. They have the advantage of unlimited cooling for free. As others have pointed out marine engines are always rated less power than the same engine in a car, because it is continuous power and cars are not. We should consider that the marine HP is the 100% level and cars are rated at 150% power.

Just like show planes, you can put a smaller prop on your boat and get more than 100% power, but they are not guaranteed to be reliable.

 

 

[Blue on Top]

@N201MKTurbo  I agree with what you are saying, but I believe that the LS series is a little different in that respect.  In other words, it was designed for a higher continuous HP than a normal automobile engine.  Yes, marine engines have unlimited water coolant.

I'm not saying that there are not challenges.  Cooling a water-cooled engine in an airplane is a huge challenge for many reasons, especially weight and drag.  Air-cooled engines have a much, much easier heat transfer equation as CHTs are significantly higher than the cooling airflow (300-400F).  On the other hand, water/liquid-cooled engines have a very small temperature delta (<90F) to transfer all that heat.  This requires lots of radiator area and slow airflow ... adding to weight and drag.

With that said, though, I would rather fly behind an engine that is nearly an order of magnitude less expensive, is more thermally efficient, will keep running with the loss of a coil/plug or two (unlike a magneto), and runs on fuel that I can get around the corner. 

[RobertGary1]

31 minutes ago, Blue on Top said:

@N201MKTurbo  I agree with what you are saying, but I believe that the LS series is a little different in that respect.  In other words, it was designed for a higher continuous HP than a normal automobile engine.  Yes, marine engines have unlimited water coolant.

I'm not saying that there are not challenges.  Cooling a water-cooled engine in an airplane is a huge challenge for many reasons, especially weight and drag.  Air-cooled engines have a much, much easier heat transfer equation as CHTs are significantly higher than the cooling airflow (300-400F).  On the other hand, water/liquid-cooled engines have a very small temperature delta (<90F) to transfer all that heat.  This requires lots of radiator area and slow airflow ... adding to weight and drag.

With that said, though, I would rather fly behind an engine that is nearly an order of magnitude less expensive, is more thermally efficient, will keep running with the loss of a coil/plug or two (unlike a magneto), and runs on fuel that I can get around the corner. 

Did you say that backwards or did I misread it? In a car if you lose a coil you lose that cylinder (assuming coil on plug as all modern cars are). In an airplane you lose a magneto and you find out at your next runup.

-Robert

[Blue on Top]

9 minutes ago, RobertGary1 said:

Did you say that backwards or did I misread it? In a car if you lose a coil you lose that cylinder (assuming coil on plug as all modern cars are). In an airplane you lose a magneto and you find out at your next runup.

-Robert

@RobertGary1  I probably did not say it clearly enough.  As you have stated, "if you lose a coil, you lose that cylinder."  I actually, intentionally, lose 3 of 6 cylinders in my Pilot every time it goes into "eco" mode using VCM (Variable Cylinder Management).  Thanks for the clarification.

[Hank]

38 minutes ago, RobertGary1 said:

Did you say that backwards or did I misread it? In a car if you lose a coil you lose that cylinder (assuming coil on plug as all modern cars are). In an airplane you lose a magneto and you find out at your next runup.

-Robert

When I lost a magneto in flight, the EGT gage was a dead giveaway--it went well above redline. Now I know what that means . . . .

[GeeBee]

Liquid cooling an aircraft engine is not that big of a deal. It is in fact almost 100 year old technology. We had huge engines liquid cooled, Merlins, Griffins, etc. flying on everything from P-51s to Lancasters. The Rutan Voyager was liquid cooled. for crying out loud.  Further we have liquid cooled engines now. How do you think all those diesel powered Diamonds fly? Let me tell you, cooling a diesel is a whole magnitude harder than a gas engines (Which is why my F-250 has a 9 gallon radiator). The "what about cooling" is a problem already solved.....a long time ago.

I can tell you this, with liquid cooling far less cylinder replacements, especially cracked cylinders and much better fuel specifics. 

Nor is the idea of "unlimited" cooling in marine engines true. Most marine engines are closed cooling now days (including mine). They are limited by the size of the heat exchanger. The advantage the aircraft liquid cooled engine over a marine is the exhaust headers and turbo chargers do not have to be liquid cooled. So the requirements of heat transfer are actually much less as all you have to do is cool the block and heads.

 

[Igor_U]

I hear a lot of people saying stock automotive engines would never made it at non stop 100% power, they are not designed for that and such. As an engineer, I agree they are not designed for that but doesn't mean they can't.

Modern Nordschleife test notwithstanding, many decades ago, Saab proved doubters they were wrong.

In mid 80, they took 3 production cars to Talladega and run them over 100,000 km at full throttle (over 220 kph).  Fuel stops, oil and tire changes reduced the average speed to over 200 kph. All of the cars made it and that was all with 2.0l turbo engine!

Ten years later they beat their own record with 6 Saabs 900, so yes, they can make it! 

[Andy95W]

Impressive, but 100,000 km at 200 kph is only 500 hours.  I’ll be more impressed when it can do 2,000 hours.

[carusoam]

So....

in yesterday’s news, The CEO of Brunswick Boats...  owner of the Mercury brand boat motors announced...in an interview... on CNBC...

They will be announcing a new style of boat engine...

 

Hard to tell what the CEO had in mind...  he is technically smart enough to understand engines...  and knows he has something different...

 

could be a significant technical leap...

Mercury has some of the coolest  complex cast aluminum pieces...

Let me know when you see it...

Best regards,

-a-

 

This is from last year...  (interesting details, as if they just joined our conversation...)

Launched in June, 2019, the Mercury Racing 450R writes a power prescription that combines unprecedented acceleration and top-speed potential with rugged reliability and the latest technology from Mercury Marine. The Mercury Racing 450R features a 4.6-liter V8 FourStroke powerhead boosted by an exclusive Mercury Racing supercharger to produce 450 peak propshaft horsepower and 439 ft. lb. of torque – 40 percent more torque than the previous Mercury Racing outboard benchmark – from an outboard that weighs as little as 689 pounds (313 Kg), the best power-to-weight ratio in the high-performance outboard category. The Mercury Racing 450R delivers all of its performance on readily available 89-octane (95 RON) pump fuel.

“The Mercury Racing 450R set a new benchmark for outboard performance and design,” said Stuart Halley, Mercury Racing general manager. “Its inclusion as a Boating Industry Top Product acknowledges the creative talent and the engineering and manufacturing prowess of the entire staff at Mercury Racing, where we always run Wide Open.”

[Hank]

Sounds like a fast new Mercury engine!

But I don't think any of us are ready to bolt a 689-lb engine onto the front of our Mooneys . . . .

[MikeOH]

Sigh....I've been following the "auto engine" in an airplane is "just around the corner" saga and debating with its fan-boys since the 1970's.  Every decade the latest auto engine is touted as the cure to aviation engine woes (which, frankly, is just their high prices!).  Ah, you say, those just were not sophisticated/modern like today's auto engines...I've heard that EVERY decade as the 'cogent' argument.

So, now we're hearing how BOAT engines with CAST IRON cylinder heads the size of small cars provide plenty of cooling with closed-loop heat exchangers with an unlimited heat sink of WATER!  Yeah, no doubt that proves auto engines will work great in aircraft

Five decades and going...pass some more of that Kool-Aid!

[Andy95W]

2 hours ago, MikeOH said:

Sigh....I've been following the "auto engine" in an airplane is "just around the corner" saga and debating with its fan-boys since the 1970's.  Every decade the latest auto engine is touted as the cure to aviation engine woes (which, frankly, is just their high prices!).  Ah, you say, those just were not sophisticated/modern like today's auto engines...I've heard that EVERY decade as the 'cogent' argument.

So, now we're hearing how BOAT engines with CAST IRON cylinder heads the size of small cars provide plenty of cooling with closed-loop heat exchangers with an unlimited heat sink of WATER!  Yeah, no doubt that proves auto engines will work great in aircraft

Five decades and going...pass some more of that Kool-Aid!

Agree 100%, Mike.  We go through this discussion here on Mooneyspace about every 9-12 months.  And the problem isn’t the FAA.  The FAA has certified automobile engines for airplane use, the current crop of diesels are some, and the EPI/Orenda V-8 conversion is another.  The problem is that the conversions simply aren’t financially or functionally worth doing.

Put more simply: if it was such a great idea, scores of kit plane builders would be using automotive engines, instead of their preferred Lycoming IO-360/540s.

The unfortunate truth is that our 1940s technology engines are extraordinarily well suited for powering our airplanes, which is why they were designed that way in the first place.  You simply won’t find 200-300 horsepower engines with a comparable price, reliability, efficiency, durability, or power-to-weight ratio.

EPI, Inc. had a great article on their website that talked about their V-8 conversion, and also a little about the rest of the crop of GM engines (LS-3, LS-7, LS-9).

http://www.epi-eng.com/aircraft_engine_conversions/evaluating_a_conversion.htm#extbadexamp

[RJBrown]

On 2/4/2021 at 10:00 PM, carusoam said:

 

How did the Porsche engine do so well in the M20L?

Best regards,

-a-

No kidding.
it was Really bad.

few sold and Porsche lost tons of money on every one.

poor performance.

‘the hurricane was merciful to Porsche in this case.

Edited February 6, 2021 by RJBrown

[N201MKTurbo]

On 2/4/2021 at 7:52 PM, MikeOH said:

So, how many pretty pennies for such a pretty face?

You don’t want to know...

[N201MKTurbo]

I just assembled a Lycoming IO-360. That engine is nothing but crankshaft and pistons. There is no wasted space in that engine.

[EricJ]

11 hours ago, Andy95W said:

The unfortunate truth is that our 1940s technology engines are extraordinarily well suited for powering our airplanes...

Or tanks.   There was a lot of crossover between aircraft and tank engines in the 1940s.   Same kinda thing, needs a reliable engine that makes a lot of torque at low rpm.

The Lycoming O-435 six cylinder was a tank engine.   It powered the M22 Locust.

https://en.wikipedia.org/wiki/M22_Locust

Edited February 6, 2021 by EricJ

[carusoam]

So...

from 80’s article above... I highlighted things that didn’t make sense to me...

Granted, it’s from the local paper... not an aviation journal...

was the story a complete fabrication..?   By the writer or by the story teller?

Or written by somebody that had no idea about what they were writing... with no competent editing..?

Its fun to read...

Are there really 60k rivets in a 60s M20J?
Would saving 200 rivets merit a sentence... 0.33%... 

-a-

—— — ————- —-

He showed the tour group pieces of the composite material that comes pre-impregnated with resin, and is pieced onto molds for structural pieces.

Bowen said the company has invested about $6.5 million in facilities and equipment in recent years, including paying about one-third of the cost of the new roofs while the City of Kerrville and Kerr County split the rest. And the Kerrville plant is making airplane parts for the sister plant in California.

The composite material lessens the number of rivets required and the man-hours to construct. Bowen said the older Ovation model is made from more than 7,000 specific parts and 60,000 rivets, while the composite material requires 200-300 fewer rivets.

They manufacture a lot of their own parts and pieces, but outsource engines, props, avionics and paint. Because they continue to repair the older Mooney airplanes, they support that with parts back to the mid-1960s Model J.

[RobertGary1]

Forget gas vs electric.  Just a motor that doesn’t shake the fillings out of your teeth and make you go deaf please. 

[carusoam]

I was referencing the article you posted... the local paper from the Hill Country...

you are 1980...

Your article became 80’s article....

had we standardized on using actual names... this would be a tad easier...

Wait a minute... I copied the article and highlighted the parts that didn’t make sense to me...

Then went back to see who wrote this garbage... it turns out it was a local paper that was more focused who paid what taxes when...  on the aviation section... they didn’t have any idea what they were writing about...

Best regards,

-a-

[Blue on Top]

The article where Tom is quoted has lots of errors ... whether misquoted or not.

Kerrville and Chino had issues (to say the least).  Towards the end Kerrville made a lot of metal parts for us (bailed us out from local California businesses overcharging us).  An outside vendor designed the M20 composite shell.  We put it in CATIA.  It is NOT structural ... and takes many MORE manhours to build. 

[Raptor05121]

On 2/3/2021 at 12:25 AM, Blue on Top said:

  As mentioned above, diesels are heavy

Continental IO-550L: 438lbs
Continental TIO-550G: 554lbs

Austro AE330: 410lbs


You also say low on power... The DA-62 can carry 7 people, or 1,600lbs useful load at 175kts on 12gph total using "only" 180hp a side. Name any gasoline twin that can do that.

Edited February 7, 2021 by Raptor05121