Automotive V8 Engine Conversions for Aircraft

[nomorecatering]

It's been long postulated that car engines are unsuitable for aviation use because of the high continuous power demands compared to motoring. Is this still true in the days of 1000 Hp Helephant crate engines (7 ltre supercharged), V8 Supercar engines that have the majority of components last indefinitely and now 600 Hp 4 litre power units are common.
The Heliphant engine is a good example. 1000 Hp put of the box, why couldn't it be run at 500 Hp in an aviation context. What am I missing. I'm not even touching the 500 CID billet engines that have set 4000 Hp on dynos. This unit costs approximately the same as a brand new TIO-550 ($130,000 USD). So has the game changed?


Some interesting videos I have discovered.

https://www.youtube.com/watch?v=KJU2OGQzC5Q

https://www.youtube.com/watch?v=IuyK2uWpBbg

https://www.youtube.com/watch?v=GqfncRRti5s&t=40s

https://www.youtube.com/watch?v=x2VIV0ZsI9c&t=192s

[Lapon]

I've seen Spitfire replicas running LS v8s and Isuzu V6s so it already been done for a while.
I'm not that familiar with them but the first I saw was about 10 years ago and I assume the kits are still being built.
Google says they are good for 250-430 HP, if you need more power you probably need a second engine or a turbine rather than a relatively obscure piston car engine with four digit HP figures.

[Slatye]

The obvious questions are:
- How are you going to cool it? I would imagine that we're looking at a large radiator, a lot of water, etc.
- How much does it weigh? Especially once you add the water cooling.
- How will you connect it to a propeller? Most propellers are happy around the 2500 - 2700RPM mark, which is also where most aviation piston engines operate. You can add gearing, but that adds weight, adds a point of failure, and potentially requires a flywheel to smooth our torque on the gears.
- Can you get it certified and persuade an aircraft manufacturer that it's a valid option?

With regards to lifespan - suppose you put this in a car, hooked up a massive trailer that will require 500hp continuously, and went for a drive on the highway at 100km/h. How far do you think you'd get before the engine needed an overhaul? 1000km? 10,000? 100,000? I'd be guessing somewhere substantially less than 100,000km. But that's only a thousand hours of use, and most aviation engines are very conservatively rated to at least 2000 hours before overhaul.

[tail wheel]

"It's been long postulated that car engines are unsuitable for aviation use because of the high continuous power demands compared to motoring."

That may have been the case 40 to 50 years ago but does not appear to be the case today. The two Mercruiser V8's in my boat are 5.7 liter Chev small blocks. According to Mercury they are designed to operate continuously in the power range 3500 RPM to 4000 RPM and are governed at 4500 RPM max by the prop size. My engines have approximately 1,100 hours since new and run perfectly. Not too thirsty, around 40 liters per hour (for two) at 3400 RPM.

Didn't the replica Southern Cross have V8 engines? VW and Subaru engines have been converted for aviation use. I suspect some of today's light weight aluminum engines and particularly the light weight turbo diesels could be re purposed for aviation use. I wonder what happened to the Porsche PFM 3200 (https://en.wikipedia.org/wiki/Porsche_PFM_3200) aircraft engine and the Chev Turbo-Air 6 (http://en.wikipedia.org/wiki/Chevrolet_Turbo-Air_6_engine) engine?

[kaz3g]

The Pawnee tug at Benalla has been running with a Chev V8 for years now and much cheaper to run/replace than original.

Jim Wickham’s scale Mustangs likewise.

there are an awful lot of RA aircraft running around on skidoo engines too.

kaz

[machtuk]

Weight, complexity, support & resale value, all these factors are why auto engines haven't flourished at the GA level. Cessna & Mooney I think dabbled in it, soon fell by the wayside. I like my simple air cooled 180HP, Lyc 4 banger, it's easy to maintain, parts are available at any milkbar around the corner & every LAME knows about them far & wide. With Electronic Ignition, a good engine monitor display & a known history I see little reason to make the powerplant complex like that of an Auto engine. A Vans RV8 powered by an Auto donk recently sold in flying condition for around half of what it would have fetched if it where properly set up with a 200HP Lyc, there's another reason!
Each to their own as choice is there but not taken up in large numbers.

[tail wheel]

I'm not into these light things but I would have thought building one with a serviceable auto engine would also be less than half the price of building one with an Lycoming or Continental aircraft engine?

[TBM-Legend]

Orenda Canada built a modified V8 replacement for PT-6 in King Air 90 many years ago.

Fact check: The Lang Kidby/Peter MacMillan Vickers Vimy replica was Chevvy V8 powered not the Southern Cross replica which has Jacobs radials in all three positions...

[currawong]

Think of the rev range required for a propeller to be efficient.

Think of the rev range required for a car engine to be efficient.

You might well say, "That can easily be solved by a gearbox". (More weight)

So you try it anyway, and find the engine destroys the gearbox. Why? No flywheel to damp out the "pulses" of power as each cylinder fires.

So you add a flywheel between the engine and gearbox, just like on a car (More weight) to get it reliable, but find you need a bigger aircraft to lift it all.

Which of course requires a bigger engine...

[nomorecatering]

Some more stuff I have seen over the years. It's interesting to witness the development of the mechanical side of things. A friend of mine has a Golf R with a Stage 3 mod package. He has done 50,000 km in it and tracks in at least every 3rd weekend as well as being a daily driver. It produces 630 hp from 2 litres......on stock internals. No rods, pistons, crankshaft or bearings have been touched.
https://www.youtube.com/watch?v=rpZYfd0GzuQ

https://www.youtube.com/watch?v=8mCbvvzj-2o&t=38s

https://www.youtube.com/watch?v=jb9mUFfjupk

https://www.youtube.com/watch?v=xWOj5_0DoQI

[Bergerie1]

I used to fly one of these - air cooled flat 4 VW engine. It worked very well!
https://www.youtube.com/watch?v=q39fnMBlKgE

[megan]

Vickers Vimy replica was Chevvy V8It was for the England Australia flight but was then fitted with BMW V-12s.

[Pinky the pilot]

The Pawnee tug at Benalla has been running with a Chev V8 for years now and much cheaper to run/replace than original.

I seem to remember that the 'autotug' was touted by GFA to be really something, but suddenly all development ceased and the project stopped with just the one example.

kaz3g; You got any info on just what transpired with that project? And why it has not proceeded?

[cattletruck]

The most disappointing thing about this thread is that they never built a production radial car engine.

Most car engines have puny little cylinders that need to work very hard to squirt out their power, whereas most aero engines prefer big bangs and operate that screw nice and slow.

[27/09]

Two of the bigger aerial ag companies on this side of the ditch spent copious amounts of money developing V8 replacements for the IO720's fitted to their Fletchers. One went down the Ford route using a 10 litre engine the other the Chev 6.5 litre engine. Both engines were slated to produce 550 BHP with a gearbox used between the engine and the propeller.

I think in one case the gear box was one of the major hurdles.

Long story short the Ford version actually flew but was cancelled before testing was finished, the Chev version was cancelled before it flew. I understand development costs and getting suitable reliability were the major factors for the projects being cancelled.

[thunderbird five]

What ever happened to the 454 aircraft engine built by Castlemaine Rod Shop some 20 years ago?

[601]

[QUOTE][ screw nice and slow /QUOTE]

mmmmmmmmmmmmmmmmm

[currawong]

Two of the bigger aerial ag companies on this side of the ditch spent copious amounts of money developing V8 replacements for the IO720's fitted to their Fletchers. One went down the Ford route using a 10 litre engine the other the Chev 6.5 litre engine. Both engines were slated to produce 550 BHP with a gearbox used between the engine and the propeller.

I think in one case the gear box was one of the major hurdles.

Long story short the Ford version actually flew but was cancelled before testing was finished, the Chev version was cancelled before it flew. I understand development costs and getting suitable reliability were the major factors for the projects being cancelled.

That machine on shutdown sounded like a 44 gal drum full of spanners bouncing down a very steep hill.

[nomorecatering]

https://www.youtube.com/watch?v=DuAUkxN5YHU

Cimco owns a company that is producing diesel outboard marine engines, they have the 200Hp unit on the market already. They are developing a marine version of the BMW I6 Quad turbo 3 ltr to be rated at 300 Hp on a light duty cycle. Interesting bit is that all these engines have a patented Belt drive systems as seen in the video. Could this work as a PSRU?
https://www.youtube.com/watch?v=Y-2B2mXnskg

[Grivation]

This is the bomb for your scale Spitty or Pony.....V12 LS Engines - Race Cast Engineering (http://racecast.com.au/v12ls/)

[tail wheel]

The most disappointing thing about this thread is that they never built a production radial car engine.

But they did build a production radial engine tank - many of the M4 Sherman tanks (49,000 built) had a Continental R975 Whirlwind radial engine. Interesting the M4A6 Sherman had a diesel Caterpillar D200A radial engine. "The Wright RD-1820 was converted to a diesel by Caterpillar Inc as the D-200 and produced 450 hp (340 kW at 2,000 rpm in the M4A6 Sherman". Who would have thought the engine family commonly fitted to the DC3 was also converted to a diesel? :eek:

But radials were fitted to a few road vehicles......... Looks like a corn cob in this monstrosity:
https://i.pinimg.com/originals/f8/7c/57/f87c577b5ac34ab6405fdaa0f4cd3604.jpg

[Sunfish]

The problem is the duty cycle. Not necessarily for the crank and bearings, but for all the other junk that hangs off the engine. Then you have another fundamental problem. The electrical system for these engines must be “on” all the time unlike a magneto ignition.

The injected Rotax 912 iS requires 7 switches to control it with some hope of failing safely. - Two ECU, Two fuel pumps, two alternators with failover logic dual injectors for each cylinder and dual ignition That might give some of you pause for thought. If conversion was that simple, wouldn’t everyone be doing it?

[Sunfish]

The gasoline powered Sherman tanks were nicknamed “Ronsons”.

[nomorecatering]

https://www.youtube.com/watch?v=agwlWlolGEg&t=1s

[Superfly Slick Dick]

Don't let this distract you from the fact that Hector is gonna be running 3 Honda Civic's with spoon engines. On top of that he just came into Harry's and ordered 3 t66 turbo's with NOS's and a Motec System Exhaust.

[Sunfish]

Fully sick Bro!

[LeadSled]

I seem to remember that the 'autotug' was touted by GFA to be really something, but suddenly all development ceased and the project stopped with just the one example.

kaz3g; You got any info on just what transpired with that project? And why it has not proceeded?

Folks,
Because, over many years, CAA/CASA stalled the "auto tug" program. Why?? Because they could, despite US experience.
There are thousands of aircraft flying behind "auto" engines, ranging from certified engines (many based on a Mercedes alloy block) through many V-8 powered smaller ag. aircraft in US, and the largest number in Experimental" aircraft.
There are some "interesting" engineering issues, particularly engines based on the Chev. "small block", these are well known and understood.
For those of you pontificating on proposition of potential propeller problems --- what, in heaven's name do you think reduction gears/drives are for??
Tootle pip!!

PS: Alvis radials were extensively used in military vehicles, plenty of boats with Merlin (Meteor) and Allison V-12s.

[currawong]

"For those of you pontificating on proposition of potential propeller problems --- what, in heaven's name do you think reduction gears/drives are for??"

Of course there are reduction drives on many aircraft engines Leadsled, that goes without saying.

Point is, many look to auto conversions due to the affordability factor, without considering the need for reduction.

A planetary reduction like on a PT6 or double helical reduction like on a Merlin adds cost.

Company I worked for tried it, sunk a lot into it and ultimately failed to achieve a reliable cost effective auto conversion that suited their operation.

Which was a shame, as they put quite some effort into it.

[Pinky the pilot]

A planetary reduction like on a PT6 or double helical reduction like on a Merlin

A question for those who may know; Which of the above is the better?
Or is it a case of 6 of one and half a dozen of the other?:confused:

Currawong; Any idea what was used in various other engines such as the big radials?

And BTW, what was used in the GTSIOs used in the C404/421 series?

[LeadSled]

Currawong,
The only Merlin/Griffon reduction gearboxes I have seen/played with have been straight cut spur gears. A major source of noise.
Tootle pip!!

PS: The pom's ability to cut helical gears, let alone hypoid bevels or double helical gears has always been rather marginal, and in the mid-1930's --- effectively non-existent.

[Andy_RR]

Currawong,
PS: The pom's ability to cut helical gears, let alone hypoid bevels or double helical gears has always been rather marginal, and in the mid-1930's --- effectively non-existent.

https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/600x825/asj_2029_20gearbox_20overhaul_201_20001_fac84807d07acd81e290 dd92c591eb914d35eb14.jpg

[lucille]

Not a proven option yet, but Raptor Aircraft (a brand new kit aircraft designed and being built by an Aussie in the USA) has a 3.0 litre turbo Diesel which is estimated to put out 350 HP.

Raptor Aircraft Home (http://www.raptor-aircraft.com/)

These VW/ Audi diesels can be truly disruptive - they can run on Jet A1 and their SFC is half that of your air cooled flat sixes.

Fingers crossed they can deliver even half of their promise.

[Andy_RR]

These VW/ Audi diesels can be truly disruptive - they can run on Jet A1 and their SFC is half that of your air cooled flat sixes.
.

No they're not. If you're lucky they'll be at or around 220g/kWh. A IO-550 is easily good for 250g/kWh and probably less when things are leaned properly - maybe closer to 235...

[lucille]

No they're not. If you're lucky they'll be at or around 220g/kWh. A IO-550 is easily good for 250g/kWh and probably less when things are leaned properly - maybe closer to 235...

I stand corrected. OK, not twice. But significantly better. The only figure I can find is for a 2007 BMW diesel of 198 g/KWh. VW have since improved their efficiency. cy. You only have to look at their automotive consumptions to get an intuitive feel.

https://en.m.wikipedia.org/wiki/Brake-specific_fuel_consumption

Ps.. I tried to look for IO-550 BSFC numbers.. do you have a link?

[Sunfish]

What “would be” converters don’t understand is that there are large and quite complex torque waves traveling up and down the crankshaft. These either get reflected, transmitted or damped at the ends. The engine designers take this into consideration but if converters mess with the dynamics then you can get weird and wonderful effects.

Examples: rotax explaining what will happen if the engine is run without a propeller, the Jabiru flywheel attachment saga, various prohibitions on rpm ranges and so on. Even the big radials had issues:

https://www.scribd.com/document/325689080/Development-of-the-R-2800-Crankshaft

[LeadSled]

Andy RR,
I did say marginal.
Could you, perhaps, guess why RR Cars used diffs. imported from USA (GM) from about 1952 ---- sorry for the minor thread drift.
I loved the example illustrated ---- a truly terrible gearbox, base don my experience rebuilding same many moons ago.
Tootle pip!!

[Sunfish]

I agree with Leadsled. There are few manufacturers in the world even today who routinely produce AGMA Class 1 gears for aircraft service. It used to be a black art - very, very skilled tradesmen were needed to set up and run the machines - which were Gleason gear hobbing machines, ANCA tool and cutter grinders and CMM’s.

These days there are gear measuring software packages for the CMM’s and they integrate directly with CNC gear hobbers. But to my knowledge, now probably out of date, it is still a black art and the mating gears have to be matched as a set. Each gear is still slightly different and you need to “tune” the hobs and grinders based on the results of your CMM analysis.

As for automotive and industrial gears - easy peasy because they ain’t Class 1. Also be aware that turbines don’t (I think) produce the torque pulses piston engines do.

[machtuk]

https://www.youtube.com/watch?v=agwlWlolGEg&t=1s

a 44G drum an hour & quarter $mill @ to buy? Yep I'll take 4!......…...

[Andy_RR]

I stand corrected. OK, not twice. But significantly better. The only figure I can find is for a 2007 BMW diesel of 198 g/KWh. VW have since improved their efficiency. cy. You only have to look at their automotive consumptions to get an intuitive feel.

https://en.m.wikipedia.org/wiki/Brake-specific_fuel_consumption

Ps.. I tried to look for IO-550 BSFC numbers.. do you have a link?


I googled "IO-550 SFC" and this came up on the first line: https://summitaviationmfg.com/wp-content/uploads/2015/04/Cessna-206_550-TI_Engine.pdf

It quotes a 0.385 lb/hp.h which is 234g/kW.h although it may have got the best economy and best power figures switched on page 3. These numbers are, however, typical of what I've seen quoted around the traps for many years. As far as BMW diesels doing 198g/kW.h that's a very best-point number and there would be some celebration in the engineering office about it. Some of the old VW PD diesels are sub-200 but it's quite difficult to do and even more difficult to spread out across a useable area. The fuel consumption you see in the day-to-day use of a car is waaaay worse than these numbers, especially on a gasoline engine. If you could cruise at a steady 100km/h at 200g/kWh in a modern car you'd be seeing 3.5-3.8L/100km That's not typical of anything I know of.

[kaz3g]

My Austin 7 had the 3speed crash box on a ‘27 magneto ignition engine with updraft Solex

I later fitted a ‘36 coil ignition with 4 speed box fitted with a remote gear stick. The block was ported and polished, polished crank, Twin side draft Solex’s and extractors.

felt like it was fast ☺️

Kaz

[Global Aviator]

https://www.v8seabee.com/conversion-kits/your-aircraft-with-a-robinson-v8.html

This one looks interesting.

[megan]

The pom's ability to cut helical gears, let alone hypoid bevels or double helical gears has always been rather marginal, and in the mid-1930's --- effectively non-existent.A little unkind I think Leadie. The Napier Sabre powering the Typhoon and Tempest was the most powerful production engine built. While it had gestational problems it became an excellent reliable engine, but its reduction gearbox was never a problem. From "Allied Aircraft Piston Engines of WWII", Graham White.
The propeller reduction gearing exemplified the innovative design and engineering that characterized the Sabre. A compounded “back gear” drove the propeller through four pinions. When multiple pinions drive a single reduction gear, the problem of equal tooth loading becomes a major issue, particularly in a heavily loaded, high-speed application with high torsional vibration such as the Sabre reduction gear. The solution Napier devised was nothing short of inspirational. Each crankshaft drove a pair of straight-cut, first-stage pinion gears, which in turn were integral with a second-stage pinion, which drove the propeller reduction gear. The second-stage pinion gears featured a helix angle, which generated an end thrust as power was transmitted. Herein lay the secret to the Sabre’s tooth load balancing system. The upper and lower pairs of pinions were connected with a centrally pivoted balance beam. Preloaded volute springs acted on the ends of the beam against the pinions, thus ensuring that the helically cut pinions would float along their longitudinal axis as they transmitted the considerable power of the Sabre and guaranteeing equal tooth loading. Even though the Sabre was beset with numerous problems as will be related, reduction gear problems were non-existent thanks to this very innovative piece of engineering. Propeller shaft radial loads were handled by massive roller and ball thrust bearings mounted back to back, the latter also taking care of propeller thrust loads. In addition, a plain bearing was mounted at the rear of the propeller shaft that also transmitted oil to the de Havilland constant-speed propeller.

[Sunfish]

Not unkind, the description indicates that they found a good solution to unequal tooth loading - that obviated the need for precision helical gears.

[lucille]

I googled "IO-550 SFC" and this came up on the first line: https://summitaviationmfg.com/wp-content/uploads/2015/04/Cessna-206_550-TI_Engine.pdf

It quotes a 0.385 lb/hp.h which is 234g/kW.h although it may have got the best economy and best power figures switched on page 3. These numbers are, however, typical of what I've seen quoted around the traps for many years. As far as BMW diesels doing 198g/kW.h that's a very best-point number and there would be some celebration in the engineering office about it. Some of the old VW PD diesels are sub-200 but it's quite difficult to do and even more difficult to spread out across a useable area. The fuel consumption you see in the day-to-day use of a car is waaaay worse than these numbers, especially on a gasoline engine. If you could cruise at a steady 100km/h at 200g/kWh in a modern car you'd be seeing 3.5-3.8L/100km That's not typical of anything I know of.

Thanks for that. I never realized how efficient they have managed to make these air-cooled flat sixes now. Indeed Google works in mysterious ways... BTW, the BMW engine whose figures I used was 2007 vintage, there have been significant improvements in sensor and ECU responses since then. I guess it depends, how light and how clean the car is when consumptions are being compared.

Nevertheless, it will be interesting to see how the diesel in that Raptor aircraft works - form memory, they're saying something like 8gph in cruise at FL 210 and 230 KTAS. If it works even half as well as claimed it will be a game changer.

[Andy_RR]

Don't hold your breath on Raptor meeting its design goals. They have done some amazing stuff building their prototype but they are out of their depth when it comes to engineering and developing stuff, demonstrated amply by the way they've missed their empty weight by, what, over 600lb? That's not even weighing a completed airframe yet. I reckon it'll be even more than that by the time it's test flight ready.

The state-of-the-art in diesel aero engines is already out there and it's too expensive and heavy but under some circumstances it works. The DA42 is where it works well enough to be useful but it's not a game changer.

[tio540]

"The DA42 is where it works well enough to be useful but it's not a game changer."

Here is an example where modern electrics can totally fail, and it is noted that the POH was not followed.

23 APRIL, 2007

SOURCE: FLIGHT INTERNATIONAL

BY: KATE SARSFIELD

Twinstar take-off crash divides Diamond and Thielert

Diamond Aircraft Industries (http://www.diamondair.com/mainpage.php)and Thielert Aircraft Engines (http://www.thielert.com/)are at loggerheads over the cause of a double engine failure involving a DA42 Twinstar (http://www.diamondair.com/news/12_12_02.php)during take-off in Germany last month. The incident, in Speyer, south-west Germany (http://maps.google.de/maps?oi=eu_map&q=Speyer&hl=en), is being probed by Germany's air accident investigation bureau (http://www.bfu-web.de/nn_41670/EN/Home/homepage__node.html__nnn=true), but the cause of the engine failure is known to be the effect of a transient drop in the electrical voltage to the two engine control units, Diamond confirms.

The European Aviation Safety Agency (http://www.easa.eu.int/home/index.html)has ordered the companies to find a swift solution, and Diamond's chief executive Christian Dries says his company is seeking EASA certification to install a small back-up battery for each engine's control unit.

When the crew of the accident DA42 arrived at the aircraft (D-GOAL) they found it had a flat battery and started up the engines using an external power unit. This deviated from the published operating procedure, which only allows one engine to be started with an external power unit - the second has to be started using aircraft-generated power.

https://www.flightglobal.com/news/articles/assets/getAsset.aspx?ItemID=17173

Just after rotation, as the landing gear was retracted, the aircraft experienced simultaneous engine failures on both TAE Centurion 1.7 diesel engines, forcing the crew to make a belly landing in a field adjacent to the runway.

Diamond says that retracting the gear placed a load on the electrical supply from the engine-driven alternators that caused a temporary voltage drop that could not be covered by the flat battery, and the accident has shown the engine control unit to be intolerant of transient electrical fluctuations.

TAE says the problem is an airframe issue, adding that being forced to issue an airworthiness directive for the 1.7, which is set to power other aircraft types, would have a huge impact on its business. Diamond dismisses these claims and argues the control unit supplied by TAE should have been able to accept a 50 millisecond transient, but it started to reset after 1.7 milliseconds, and during the engine control unit reset the propeller system sensed the power loss and auto-feathered.

Meanwhile, Diamond has issued a service information bulletin that clarifies standard operating procedures. Dries says the question remains: who is to pay for the fix?


Blogs from Aero 2007 - Friedrichshafen (http://www.flightglobal.com/blogs/plog-blog/)

[Sunfish]

As I said in post #22, anything that has electronics requires a continuous stream of relatively clean electricity and switches that are reliable. Rotax 912 iS in theory gets around the Diamond problem by having a dedicated engine alternator A and an airframe power alternator B which also charges the battery. A and B are tied together at engine start, then separate with A powering ECU’s ignition, injections and fuel pumps. If A fails, B takes over instantaneously and dumps the airframe load and battery charging. There is also a dedicated battery only mode, but I’m not sure if that automatically fails over if both alternators fail.

Moral: you want a battery good for at least 30 min if everything goes wrong.

[Skydawg]

There is a lot of bad info out there on auto conversions. My Cessna 172 has an aluminum V8 on it and works way better than the dinosaur 0320 it replaced. Not only does it out perform it, but it cost less than $20 USD per hour to operate compared to $68/hr with original engine. However, not all engines make good aircraft engines, and even then, require engineering skills typically outside a pilots skill set. My C172 is quieter, consumes any automotive gas or AVGAS you want to put in it- although I avoid AVGAS due to higher price and i need to change oil and clean plugs a lot more often due to the lead- and parts are cheaper....not to mention it doesn’t pollute the air as much. It even has OBD which displays fault codes if something goes bad, making maintenance easier....when was the last time you saw a modern car broken down on the side of the road? It’s also easier to fly with no mixture control or carb heat. Even the certified diesel aircraft engines use an automobile engine block.

the right converted engine is way better than the 1940 stuff the industry still forces down our throat, and in my opinion, more reliable. I currently fly the B787 and everything is electric, and very reliable. The only thing holding technology back is Lycoming and Continental that have not needed to improve their product because they have a monopoly so why spend the money. Certification agencies share much of the blame as well by using 60 year old cert regulations and demanded expensive cert process..

[nomorecatering]

Mercury Marine introduces a 7.6 litre V12 marine engine rated at 600 hp rated at a light duty cycle (ie pleasure/recreational boating). They will launch a 500hp version designed for meduim duty commercial rating 9around 3000 hrs per year, 80% time at full load), 3000+ hrs between overhauls.

https://www.youtube.com/watch?v=Y90eo4cU_zM

[McLimit]

Judas Priest, what a beast ^^^^^

[Less Hair]

Here is a new V12:
It is a newly developed aviation engine, certified, done by some former formula one car engine developers.

https://youtu.be/_bHfsJ1s0e8

https://www.flyer.co.uk/red-aircraft-seeks-stc-partners-for-500hp-v12/?cmpredirect

[mustafagander]

Hey Dawgie,
Lots of engineering required. Auto engines HATE running for long times at constant RPM. The lube system relies on RPM changes to lube the cylinders for a start.
That's why Subaru boxers aren't converted to fly much. An outstanding engine but need RPM change to survive. I've been running highly tuned Subis for many years and this is well known. An hour on the freeway with no traffic can be risky when you're pulling 200Kw at the wheels. Constant RPM is a no-no. Maybe keeping the speed limit would help?? ;)

[Skydawg]

Dawgie?
not sure what your engineering background is but most issues with auto conversions are engines running at or near manufactured HP and torque ratings, and no transmission to act as a buffer, not to mention pulse fatigue and shaft alignment issues. As far as constant power stresses go at prolonged cruise settings, again mist auto conversions operate near 100 percent of max rated power. Marine engines have far more stress than aircraft engines and do fine.

​​​​​​Check out www.corsairpower.com. They have a V8 engine for Cessna's with a lot of info on the topic.

[Global Aviator]

Looking more at that RED - https://red-aircraft.com/product/ seems like a wow, Jet A1, 500hp!

As for the Subi, surely with modern FADEC could easily set up RPM changes every xx mins, would even help keep you awake :).

What were those V8’s years ago Orenda?

[nomorecatering]

https://www.youtube.com/watch?v=8zykwnETUlk&t=156s

https://www.youtube.com/watch?v=qyyvwitOigQ&t=10s

https://www.youtube.com/watch?v=jeYO3aO0_p0

[Pinky the pilot]

Most interesting, nomorecatering! :ok:

I wonder how one of those Air Tractors would go as a Glider Tug?:E:hmm:

[WingNut60]

........PS: The pom's ability to cut helical gears, let alone hypoid bevels or double helical gears has always been rather marginal, and in the mid-1930's --- effectively non-existent.

You've never pulled the lid off a Dean, Smith and Grace gearbox then?????

[Lead Balloon]

https://www.youtube.com/watch?v=8zykwnETUlk&t=156s

https://www.youtube.com/watch?v=qyyvwitOigQ&t=10s

https://www.youtube.com/watch?v=jeYO3aO0_p0I'd be interested to see any evidence that supports the view that the costs of buying and maintaining a V12 piston aero engine are lower than buying and maintaining a turbine aero engine.

[Uplinker]

Hey Dawgie,
.........The [auto engine] lube system relies on RPM changes to lube the cylinders for a start......

Can I drift the thread for a second to ask why this is - what is the mechanism, and why does it need rpm changes to work ?

Some auto engines I have worked on have oil holes in the con-rods to direct a jet of oil up into the cylinders from underneath.

Other engines I have seen have oil jets mounted at the bottom of each cylinder, spraying upwards.

[nomorecatering]

For compeletness I should Deltahawks now certified engine. Some interesting possibilities in a 6,8 and 12 cylinder configuration as it appears modular in nature.

https://www.youtube.com/watch?v=vJkA8VI6QdY&t=1s

[Peter Fanelli]

Yes there are now manufacturers producing 700-1000 hp cars on the street.
Google muscle car crashes and you'll see that they don't have to be built to last.

[cooperplace]

My Cessna 172 has an aluminum V8 on it .......

I currently fly the B787 ..

Thank you. Can you please tell us what V8?
And feel free to tell us more about the 787.

[lucille]

It is interesting that there are surprisingly few, if any, successful V8 conversions.

It would seem that the simplicity of air cooling and direct drive trumps the claimed efficiency of the alternatives.

(Rotax, the exception, doesn’t yet produce higher powered engines)