V12 Diesel

Homebuilt Aircraft & Kit Plane Forum

Help Support Homebuilt Aircraft & Kit Plane Forum:

PTAirco

Well-Known Member
Joined
Sep 20, 2003
Messages
3,614
Location
Corona CA
Does anyone have a Torque or HP curve for this engine?

Also, what attributes are required in an engine that makes it's peak HP at direct drive RPMs vs. an engine that makes it's HP at much higher RPMs, like most Automotive engines? Is it just a matter of stroke length and bore size? Or is there more to it than that?
Yes, basically it is stroke length that makes the difference. Torque might as well be called "leverage" and a crank with more stroke produces more leverage. Of course, cams and valve timing etc would be tailored to that particular rpm, but that makes only a comparatively minor difference.

If you took at 0-360 Lycoming and a 350 Chevy V8, and played with cams a little they would show a very similar power curve up to 2700 rpm, both being fairly 'square' bore and stroke ratio engines.

If you look engines from WW1 to the 1920s you see engines swinging enormous propellers at extremely low rpm - all these engines had extremely long strokes compared to their bores. Far more efficient for aero engines. Even back then they felt if an engine had to go much over 1800rpm, they really ought to gear down the propeller. The engineers back then would probably cringe at at our 2700 toothpick-props whizzing around.
 

Midniteoyl

Well-Known Member
Joined
Sep 3, 2003
Messages
2,406
Location
Indiana
making one HP for one hour will swallow about 0.45lbs of fuel (for gasoline engines) and about 0.35-0.4 for Diesels.
Technically speaking, this is not true any more... OEM engines in the last 10 years or so have been in the 'under .4' range, not .45 or more commonly quoted '.5'. 'Crate' engines are higher, but not always. In fact, there was a Vortech based motor just built that was in the .34-.4 range during its entire RPM range... and it made over 450hp. Nascar engines are routinly in the .3's.
 

PTAirco

Well-Known Member
Joined
Sep 20, 2003
Messages
3,614
Location
Corona CA
Technically speaking, this is not true any more... OEM engines in the last 10 years or so have been in the 'under .4' range, not .45 or more commonly quoted '.5'. 'Crate' engines are higher, but not always. In fact, there was a Vortech based motor just built that was in the .34-.4 range during its entire RPM range... and it made over 450hp. Nascar engines are routinly in the .3's.
Interesting - it would be nice if car manufacturers published more SFC figures, without having to dig around for them. But I guess they believe the car buying public to be a pretty ignorant bunch (correctly...?) and maybe they consider this kind of info just too far above our heads.
 

B100

Well-Known Member
Joined
Jan 23, 2014
Messages
66
Location
Albufeira , Portugal
Hi all! The V12 is nice, but there are other options that might be a better fit for your requirements , so here is the full list ;

List of Volkswagen Group diesel engines - Wikipedia, the free encyclopedia

And let me remind you that these engines respond very well to chip tuning, increasing power and torque, while bringing down fuel consumption!
The V 12 can be made to produce around or over 600 hp !
But don't take my word for it, see for yourselves ;

Audi Q7 6.0 V12 TDI Quattro 500PS/368kW

My personal home "fleet" is powered by two of these engines on the list ( 1,9 TDI) and they are great engines, and can even run on 100% home made Biodiesel!:)

So consider .....lower fuel consumption , and home made fuel ! :gig:
 

JamesG

Well-Known Member
Joined
Feb 10, 2011
Messages
2,408
Location
Columbus, GA and Albuquerque, NM
Yes, marketing types hear engineers as, "blah, blah, blah, blah". and then do what they think will sell the most units.

Peak torque and rpm can occur at different points. It all depends on what you want/need the engine to do. Spin a shaft with lots of power or lots of speed.
 

B100

Well-Known Member
Joined
Jan 23, 2014
Messages
66
Location
Albufeira , Portugal
Yes, marketing types hear engineers as, "blah, blah, blah, blah". and then do what they think will sell the most units.

Peak torque and rpm can occur at different points. It all depends on what you want/need the engine to do. Spin a shaft with lots of power or lots of speed.
Hi James, I honestly dont get what you mean with your post! could you please clarify?
 

B100

Well-Known Member
Joined
Jan 23, 2014
Messages
66
Location
Albufeira , Portugal
Sorry, that was a post that was related/should be benieth another post but got shuffled back out of context.
No problem! Don´t know if you have come across this before, but while some talk about what if? regarding diesel conversions and the endless bla bla bla about weight & power, some folks here across the pond have actually done it!
so check out these links !

http://gazaile2.free.fr/caracteristiqu
http://gazaile2.free.fr/englishInformations.pdf

Now imagine what could be done with bigger more powerful engines! Granted the best options are here in Europe, as 60% of all motor vehicles on the road are diesels , so we are spoilt for choice :).
 

B100

Well-Known Member
Joined
Jan 23, 2014
Messages
66
Location
Albufeira , Portugal
Wow! you made my day...lol....night! Its good to know that myths are being broken! I always questioned the fact that a reduction drive was needed for a diesel!
Why? because it didnt make sense to me that if the "ideal" rpm for prop eficiency is in the 2000 t 2700 rpm range, (depending on the variables) that wasn´t taken into consideration when applied to diesel engines.
Most current automotive diesels achieve their max torque, and retain that flat torque curve, from as low as 1600 rpm to 3000 rpm ! Max hp is achieved at 4000 rpm or lower !
So best torque coincides with best prop rpm regimes! The result is you dont need a heavy complex reduction system, but a lighter simpler means of bolting on the prop!
A lot of the perceived dificulties, are due to a mentality based on either certified engines, or gasoline automotive conversions, and the comparisons made! But as the article by mr. DuCros states if you aproach the technical issues by embracing and working with the specifics of a diesel engine, then the perceived limitations are overcome, and one reaps the benefits of diesel power that translate into, fuel economy, reliability , and long engine life !

Another benefit that the article also mentions, and I can atest to is the availability of these engines new or used, as well as cheap spares!

In the 300 pound range 2 liter engines can be had for as low as 700 euro! these engines put out between 110 to 180 hp, and can even be made to produce more! Now that not mght not sound so good in aero engine terms, but when you factor in lower fuel burn, it does narrow or even eleminate it completely !

When Lyc 540 power level territory ir reached then automotive diesels equal and mostly beat the aero engines!
waiting to see who is the first to take the plunge, and hang one of these on a decent airframe :)
 

rv6ejguy

Well-Known Member
Joined
Jun 26, 2012
Messages
4,282
Location
Calgary, Alberta, Canada
There are no 4 stroke diesels out there flying which beat the power to weight ratios of traditional aircraft engines and especially turbocharged ones (let's remember to compare apples to apples here). Let's also compare certified aero diesels to certified SI engines. Cost wise, the current crop of certified aero diesels are all way more expensive to buy in the first place.

The only way for a diesel to even approach these levels is with massive boost pressures, limiting both engine life and altitude performance with single stage turbos. No free ride here.
 

B100

Well-Known Member
Joined
Jan 23, 2014
Messages
66
Location
Albufeira , Portugal
There are no 4 stroke diesels out there flying which beat the power to weight ratios of traditional aircraft engines and especially turbocharged ones (let's remember to compare apples to apples here). Let's also compare certified aero diesels to certified SI engines. Cost wise, the current crop of certified aero diesels are all way more expensive to buy in the first place.


The only way for a diesel to even approach these levels is with massive boost pressures, limiting both engine life and altitude performance with single stage turbos. No free ride here.


That is correct , " There are no 4 stroke diesels out there flying which beat the power to weight ratios of traditional aircraft engines"
Just because they are not flying does not mean that on specs alone they dont beat SI engines certified or not, or even the certified aerodiesels !
Now Ross with your experience in auto conversions its a pity you dont have access to the variety o diesel engines we have on this side of the pond, as I am sure you would do well, but you would have to loose your aparent anti diesel bias!

But part of the problem comes from as you say " comparing apples and apples" You make a living from auto conversions of SI engines, and to do so, some mods had to be done for that to work! The same principal applies to the conversion of a auto diesel engine, but work has to be done around the specific technical pros and cons of a diesel.

"The only way for a diesel to even approach these levels is with massive boost pressures, limiting both engine life and altitude performance with single stage turbos. No free ride here."

Well all current diesels are all tubocharged and have very high compression ratios, so I doubt engine life would be an issue, besides considering what is demanded in terms of work, a diesel will have a esier life as a aero engine then as a normal auto engine ! In general there is a lot of margin for power upgrades in all current diesel engines! Its common for the same engine to be on the market with 3 or 4 diferent power levels! And what changes ? engine management, injectors, injection pressure and parameters, turbos, intercoolers, air filters, exaust systems, among many others, but the basic engine is the same !

In spite of all the nay sayers, its inspiring that some people just shut them out and prove it can be done, but old habbits die hard and the aeronautical community is by nature very conservative.
I say we should be striving to do it better, not denying what has been done!

Now for comparisons:
TIO-540-AF1B270HP weight 493 lbs dry - vs- Audi 3.0 V6 272 hp 478 lbs dry (can be chipped to to 336 hp, 2014 Q7 comes with 320hp )

TIO-540-AE2A 350 hp weight 548 to 595 lbs dry -vs- Audi 4,2 V8 349 hp 567 lbs dry (can be chipped to 432 hp)

These are just a couple of examples, so Ross you are right on one point, these engines are not Flying! But the do exist and have better power to weight ratios.

Now even if you had some type of reduction or other form of mouting a prop , adding another say 80 lbs, you still end up with a mtow equal or less to a Lyc 540 because of the lower fuel comsumption!

But you are right.....they are not flying....yet...but they exist!
 

BJC

Well-Known Member
HBA Supporter
Joined
Oct 7, 2013
Messages
13,091
Location
97FL, Florida, USA
B100 said:
Now for comparisons:
TIO-540-AF1B270HP weight 493 lbs dry - vs- Audi 3.0 V6 272 hp 478 lbs dry (can be chipped to to 336 hp, 2014 Q7 comes with 320hp )
For comparison purposes, can you provide estimated weights of the total propulsion systems for each of there two engines? Including fuel pumps, cooling systems, coolant, PSRU if needed, propeller, propeller RPM controller, exhaust system, mounts, etc.?

Thanks,


BJC
 

rv6ejguy

Well-Known Member
Joined
Jun 26, 2012
Messages
4,282
Location
Calgary, Alberta, Canada
There are no 4 stroke diesels out there flying which beat the power to weight ratios of traditional aircraft engines and especially turbocharged ones (let's remember to compare apples to apples here). Let's also compare certified aero diesels to certified SI engines. Cost wise, the current crop of certified aero diesels are all way more expensive to buy in the first place.


The only way for a diesel to even approach these levels is with massive boost pressures, limiting both engine life and altitude performance with single stage turbos. No free ride here.


That is correct , " There are no 4 stroke diesels out there flying which beat the power to weight ratios of traditional aircraft engines"
Just because they are not flying does not mean that on specs alone they dont beat SI engines certified or not, or even the certified aerodiesels !
Now Ross with your experience in auto conversions its a pity you dont have access to the variety o diesel engines we have on this side of the pond, as I am sure you would do well, but you would have to loose your aparent anti diesel bias!

But part of the problem comes from as you say " comparing apples and apples" You make a living from auto conversions of SI engines, and to do so, some mods had to be done for that to work! The same principal applies to the conversion of a auto diesel engine, but work has to be done around the specific technical pros and cons of a diesel.

"The only way for a diesel to even approach these levels is with massive boost pressures, limiting both engine life and altitude performance with single stage turbos. No free ride here."

Well all current diesels are all tubocharged and have very high compression ratios, so I doubt engine life would be an issue, besides considering what is demanded in terms of work, a diesel will have a esier life as a aero engine then as a normal auto engine ! In general there is a lot of margin for power upgrades in all current diesel engines! Its common for the same engine to be on the market with 3 or 4 diferent power levels! And what changes ? engine management, injectors, injection pressure and parameters, turbos, intercoolers, air filters, exaust systems, among many others, but the basic engine is the same !

In spite of all the nay sayers, its inspiring that some people just shut them out and prove it can be done, but old habbits die hard and the aeronautical community is by nature very conservative.
I say we should be striving to do it better, not denying what has been done!

Now for comparisons:
TIO-540-AF1B270HP weight 493 lbs dry - vs- Audi 3.0 V6 272 hp 478 lbs dry (can be chipped to to 336 hp, 2014 Q7 comes with 320hp )

TIO-540-AE2A 350 hp weight 548 to 595 lbs dry -vs- Audi 4,2 V8 349 hp 567 lbs dry (can be chipped to 432 hp)

These are just a couple of examples, so Ross you are right on one point, these engines are not Flying! But the do exist and have better power to weight ratios.

Now even if you had some type of reduction or other form of mouting a prop , adding another say 80 lbs, you still end up with a mtow equal or less to a Lyc 540 because of the lower fuel comsumption!

But you are right.....they are not flying....yet...but they exist!;)
I don't have a bias towards diesels like you do, I simply look at the numbers and the track record in the air. Talking and dreaming about something does not make it reality. Like I said before, build it, get it in the airplane and fly it for a few years to prove it. Paper engines and paper airplanes mean little in the real world. The only production aero diesel to meet decent weight, reliability and cost goals has been the WAM 2 stroke however it's SFCs are no better than existing SI aero engines. All the 4 strokes (including auto based ones) are much heavier and the aero specific ones are crazy expensive, wiping out any cost savings in the long run, at least over here. Many of these have also had reliability issues along the way.

To be clear, I do not make money from doing auto conversions- we don't sell engines.

With regards to your feelings about diesel engine life, high boost pressures exact a toll on all engine types. The Thielert and SMA both had serious reliability issues (pistons and case fretting). The aviation application is little like the automotive load cycle. Ask yourself why everyone doesn't just run 80 inches in auto diesels all the time? The new EPS V8 aero diesel uses steel pistons instead of aluminum and a CGI block to avoid some of these issues. Weight on auto diesels is always a secondary design factor to reliability. Of course you can use an auto diesel in an aircraft, it's been done successfully many times but it's always heavier and never performs as well as a similar turbocharged SI engine. If fuel economy is your main goal, it could be very successful for you.

As far as performance goes, diesels are way behind. The French installed an SMA in an NXT and went to Reno a few years back and were slower than many normally aspirated fixed gear aircraft. They were not even in the same league as the other 2 NXTs (about 100-150 mph slower). https://www.youtube.com/watch?v=OE7lRu1HhHY Most race diesels can't even match the specific power output of production naturally aspirated SI engines.

Essentially, almost all hp increases on the diesel come from higher mass flow through higher boost pressures. Things like injectors, different mapping, turbos, intercoolers etc. simply help support the higher mass flow and boost.

The Audi is going to weigh more than you think by the time a gearbox is added. Upping hp through added boost works with the Lycoming too- 800hp and with geared SI engines even more so if we want to compare apples to apples. We have 3.8 Skyline engines making a reliable 2000hp (AMS) Texas Invitational https://www.youtube.com/watch?v=pcHumlKI5EE.

Talk like this about the "performance" of diesels comes from people who have little knowledge about turbocharged SI engines. SI engines massacre diesels in every form of racing except endurance racing with fuel limits. Let's remember the best turbo SI engines have specific outputs of around 1000hp/L, far in excess of any race diesel.

I'd add that here in my city, diesel fuel costs about 20% more than pump gas, wiping out any significant savings with diesel engines. Of course this varies depending on where you live.

Anyway, as before, when we discussed this, I encourage you to build it, fly it and show us...
 
Last edited:

B100

Well-Known Member
Joined
Jan 23, 2014
Messages
66
Location
Albufeira , Portugal
BJC[/QUOTE]
For comparison purposes, can you provide estimated weights of the total propulsion systems for each of there two engines? Including fuel pumps, cooling systems, coolant, PSRU if needed, propeller, propeller RPM controller, exhaust system, mounts, etc.?

Thanks,


BJC
Hi BJC ! I have no idea in regards to the Lyc 540, but I´m sure there will be a lot of people on HBA that would know! In fact I would like to know myself!
As for the Audi, I have seen them in Audi and VW vehicles , and coolant and rad would amount to around 26 lbs, depending on the version no extra fuel pump is needed. The exaust I have no idea, but as with most auto conversions, a lighter custom exaust manifold would shave some weight off by replacing the heavy stock one. Mounts? No idea, cause ithasnt been done yet!
Psru if needed might amount to around another 80 Lbs!( Just very rough guess based on the automotive gear box)

The point is yes! it would weigh more ready to fly then the 540, but the added weight would be compensated by lower fuel burn and cost , as well as lower aquisition and maitenance costs ! I am also sure that TBO would be double, and cheaper too!

Now this discussion is academic, after all that is part of the point and fun of being on HBA right! some of us on HBA are luky enough to have build, or are building an aircraft, and others like me intend to, at some time in the future (when kids are out and supporting themselves) lol.....but not there yet !
I have been learning a lot for some years on HBA and other related sites, recently I signed up to take part , and have no problem asking when I dont know something, but I do feel that there are too many people focusing on problems and reasons not to do something, instead of focusing on how to get around them!

Here is an example of what I mean : If somebody proposed puting a engine on a plane that only produces 55 hp and a ready to fly installed weight of 242 lbs, most would say, its too heavy!
But consider the said engine, passinger, pilot, and 4 hours + reserve doing 200kmh or 124mph at a MTOW of 450 kg or 990 lbs! Possible? yes its been done
works well and is very eficient!

The same aircraft flown solo did a 845 mile trip in 7,5 hours on just under 2 galons an hour! these figures are only atainable with a diesel!

So my question in regards to my comparison, is what can we achieve with a engine that has a better power to weight ratio, and better sfc numbers ?

Just food for thought ! Isnt that what progress is? daring to ask ? daring to question!
 

B100

Well-Known Member
Joined
Jan 23, 2014
Messages
66
Location
Albufeira , Portugal
I don't have a bias towards diesels like you do, I simply look at the numbers and the track record in the air. Talking and dreaming about something does not make it reality. Like I said before, build it, get it in the airplane and fly it for a few years to prove it. Paper engines and paper airplanes mean little in the real world. The only production aero diesel to meet decent weight, reliability and cost goals has been the WAM 2 stroke however it's SFCs are no better than existing SI aero engines. All the 4 strokes (including auto based ones) are much heavier and the aero specific ones are crazy expensive, wiping out any cost savings in the long run, at least over here. Many of these have also had reliability issues along the way.

To be clear, I do not make money from doing auto conversions- we don't sell engines.

With regards to your feelings about diesel engine life, high boost pressures exact a toll on all engine types. The Thielert and SMA both had serious reliability issues (pistons and case fretting). The aviation application is little like the automotive load cycle. Ask yourself why everyone doesn't just run 80 inches in auto diesels all the time? The new EPS V8 aero diesel uses steel pistons instead of aluminum and a CGI block to avoid some of these issues. Weight on auto diesels is always a secondary design factor to reliability. Of course you can use an auto diesel in an aircraft, it's been done successfully many times but it's always heavier and never performs as well as a similar turbocharged SI engine. If fuel economy is your main goal, it could be very successful for you.

As far as performance goes, diesels are way behind. The French installed an SMA in an NXT and went to Reno a few years back and were slower than many normally aspirated fixed gear aircraft. They were not even in the same league as the other 2 NXTs (about 100-150 mph slower). https://www.youtube.com/watch?v=OE7lRu1HhHY Most race diesels can't even match the specific power output of production naturally aspirated SI engines.

Essentially, almost all hp increases on the diesel come from higher mass flow through higher boost pressures. Things like injectors, different mapping, turbos, intercoolers etc. simply help support the higher mass flow and boost.

The Audi is going to weigh more than you think by the time a gearbox is added. Upping hp through added boost works with the Lycoming too- 800hp and with geared SI engines even more so if we want to compare apples to apples. We have 3.8 Skyline engines making a reliable 2000hp (AMS) Texas Invitational https://www.youtube.com/watch?v=pcHumlKI5EE.

Talk like this about the "performance" of diesels comes from people who have little knowledge about turbocharged SI engines. SI engines massacre diesels in every form of racing except endurance racing with fuel limits. Let's remember the best turbo SI engines have specific outputs of around 1000hp/L, far in excess of any race diesel.

I'd add that here in my city, diesel fuel costs about 20% more than pump gas, wiping out any significant savings with diesel engines. Of course this varies depending on where you live.

Anyway, as before, when we discussed this, I encourage you to build it, fly it and show us...
Hi Ross, I don't have a bias for Diesels, but do have a bias for efficiency and lower fuel and running costs, and in that field Diesel is unbeatable!

Unfortunately I dont have the means to accept your challenge, (wish I could :) ) and build and fly what I theorise ! But lets not forget that all achievements be it in automotive or aeronautical terms started as theories dreams and yes, as paper planes ! In fact that's how most aircraft flying today started, as an idea put to paper ( These days its more likely to be a computer) Progress only happens when one challenges what is, and I seem to recall reading somewhere on HBA a quote to that effect by Burt Rutan .

I am afraid that my technical expertise in terms of mechanics is limited to part time work in a local auto workshop where 80% of their work is on Diesels, hence my contact with these engines! I also make my own diesel fuel (biodiesel) to power my home "fleet" lol....so if anybody has questions on the making and use of Biodiesel, feel free to ask!

Just to set the record straight , I am aware that a SI engine when turbocharged will always outperform a diesel in terms of HP! we have 1,4 and 1,6 engines GT versions here that come stock with 140 to 180 hp , but engine life is....low!
And yes racing SI engines are capable of 1000 HP/L but they last only a few hours and then are scrapped or blow, so that not what we are talking about. Yes Lycs and other aero-engines can be boosted for racing purposes to very high hp figures, but again engine life is dramatically reduced and TBO times are short,or TBR, so again not what I am talking about.
I agree when it comes to 2 stroke Diesels not the way to go, (Deltahawk comes to mind) WaM or others!
It does seem we agree, that when endurance and fuel limitations are an issue, as you rightly point out, is the case in endurance racing then Diesels shine!( Le Mans has been dominated by diesels last few years, even when the regulations were changed to benefit SI engines)
My point is endurance racing attributes are closer than any other for a plane that will fly high fast and long distance on cheaper (jetA) and more readily available multi fuel source ( Jet A , diesel , biodiesel, or a mix of the 3) ! Diesel might be 20% higher on that side of the pond, which is odd because its cheaper than gasoline in most places round the world.
But even in other classes (see my previous links) they still do well !

In terms of engine life the power levels mentioned are stock! and I have come across some of the mentioned engines with between 300000 and 400000KM without any issues, just with normal maintenance ! so the boost to attain those power levels has no effect whatsoever on engine life !

As mentioned unfortunately I cannot take you up on your challenge! But you cannot deny the fact that some have, and are doing just that , and thus contributing to aeronautical progress , and isn't that what we all want?:)
 

rv6ejguy

Well-Known Member
Joined
Jun 26, 2012
Messages
4,282
Location
Calgary, Alberta, Canada
Hi Ross, I don't have a bias for Diesels, but do have a bias for efficiency and lower fuel and running costs, and in that field Diesel is unbeatable!

Unfortunately I dont have the means to accept your challenge, (wish I could :) ) and build and fly what I theorise ! But lets not forget that all achievements be it in automotive or aeronautical terms started as theories dreams and yes, as paper planes ! In fact that's how most aircraft flying today started, as an idea put to paper ( These days its more likely to be a computer) Progress only happens when one challenges what is, and I seem to recall reading somewhere on HBA a quote to that effect by Burt Rutan .

I am afraid that my technical expertise in terms of mechanics is limited to part time work in a local auto workshop where 80% of their work is on Diesels, hence my contact with these engines! I also make my own diesel fuel (biodiesel) to power my home "fleet" lol....so if anybody has questions on the making and use of Biodiesel, feel free to ask!

Just to set the record straight , I am aware that a SI engine when turbocharged will always outperform a diesel in terms of HP! we have 1,4 and 1,6 engines GT versions here that come stock with 140 to 180 hp , but engine life is....low!
And yes racing SI engines are capable of 1000 HP/L but they last only a few hours and then are scrapped or blow, so that not what we are talking about. Yes Lycs and other aero-engines can be boosted for racing purposes to very high hp figures, but again engine life is dramatically reduced and TBO times are short,or TBR, so again not what I am talking about.
I agree when it comes to 2 stroke Diesels not the way to go, (Deltahawk comes to mind) WaM or others!
It does seem we agree, that when endurance and fuel limitations are an issue, as you rightly point out, is the case in endurance racing then Diesels shine!( Le Mans has been dominated by diesels last few years, even when the regulations were changed to benefit SI engines)
My point is endurance racing attributes are closer than any other for a plane that will fly high fast and long distance on cheaper (jetA) and more readily available multi fuel source ( Jet A , diesel , biodiesel, or a mix of the 3) ! Diesel might be 20% higher on that side of the pond, which is odd because its cheaper than gasoline in most places round the world.
But even in other classes (see my previous links) they still do well !

In terms of engine life the power levels mentioned are stock! and I have come across some of the mentioned engines with between 300000 and 400000KM without any issues, just with normal maintenance ! so the boost to attain those power levels has no effect whatsoever on engine life !

As mentioned unfortunately I cannot take you up on your challenge! But you cannot deny the fact that some have, and are doing just that , and thus contributing to aeronautical progress , and isn't that what we all want?:)
We agree that the BSFC for 4 stroke diesels is better than most SI engines- no argument. Here pump gas is around .83c/ L and diesel is 1.05. This means the diesel is not going to save any money over a comparable SI powered car.

Absolutely agree that all progress starts with a dream but the dream must have some foundation in reality.

At the low specific output levels you are talking here, SI engines easily last a very long time also. Our shop turbo 240SX has 330,000 km on it now after 17 years of being turbocharged, beat on at the racetrack etc. Compression is still excellent, oil consumption 0.5L in 10,000 km. I just change oil in it and drive it. I think you will find that engine life in the aero application (continuous high power) is reduced considerably compared to automotive, especially when the hp is increased over stock levels. My point was simply that diesels can't match the same power to weight ratios as SI engines and weight is important in aircraft. Any turbo engine can have better power to weight ratios simply by increasing manifold pressure.

Bio diesel is not available around here anywhere nor is jet fuel at most smaller airports. You'd have to plan your fuel stops accordingly.

Lemans is a fuel economy race, not a speed race. The rules heavily favored diesels for many years. In this rule structure, the outcome is going to be pretty clear.

The 2 stroke WAM is a success if you prefer a diesel. My point was that is does nothing better than comparable legacy SI aero engines.
 

B100

Well-Known Member
Joined
Jan 23, 2014
Messages
66
Location
Albufeira , Portugal
Not true at all. For less effort you could install a current direct injection SI engine for a better result. There are other options also.

Great! You seemed to have missed my point, but give me an example! I am always ready and eager to learn!


You're ignoring the answers.
Really! then do a fact check , because you are ignoring the facts !

My main point is simple ! Successful conversions have been done and are flying, using less then ideal power to weight ratios that would have precluded any use of those engines! Yet it has been made to work and some are close to a 1000 hours (Dieselis and Gazaile ) with no apparent problems. Will there be some? Sure there will, that's why the aircraft are classed or termed as experimental. But even certified well established aero engines fail so..... its only question of time and more aircraft flying to build up knowledge and establish some parameters!

With these facts in mind , my question regards the fact that there are some stock auto diesel engines with power to weight ratios that can rival or get pretty close to current certified aero engines , so if its been done with the other ones why not with these?

People on HBA keep asking and wishing for a decently powered and priced diesel to hang on a plane all I did was list some candidates, so if want sue me for that go ahead, but don't confuse opinions with facts!
 
Top