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Jet-A/Diesel Vans RV

ruans

I'm New Here
Hi all,

This is my first post and thought I would post it here as it might be worthy news.

I have always like aircraft but, I never really had exposure to Vans RV. I knew about them, saw them fly but, was not involved in any Vans aircraft until, I started hanging around a workshop building these. I got a brand new excitement for GA since then.

I started making some videos around a local South African business building Vans RV aircraft as I took up filming as a new hobby.

With this came an opportunity to film the progress of a real exciting development of a Jet-A/Diesel powered RV9. Other models will follow suit and I hope to document this as well.

Thought I would share this for those interested in alternative power plants for the Vans RV aircraft. This video is an "unboxing video" of the power plant with the rest of the progress to come soon.

https://www.youtube.com/watch?v=ATWHU2jfvH0&list=PLXghOwFbnzJT2edhqcMS6dtGaTU1P25vV&index=2
 
Oh man that's precisely the engine I would love to put in a 9A, but Continental won't sell to the experimental market here in the US.
 
Welcome to VAF, Ruan!! Hope you will post the progress. This engine seems perfect for your part of the world.
 
Oh man that's precisely the engine I would love to put in a 9A, but Continental won't sell to the experimental market here in the US.

That would be my understanding as well.:eek:
But, who knows what will happen after this one takes to the sky.
 
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Welcome to VAF, Ruan!! Hope you will post the progress. This engine seems perfect for your part of the world.

Thank you, Bill.
I will indeed keep posting more progress videos.
I will return for an update soon. :D
 
Oh man that's precisely the engine I would love to put in a 9A, but Continental won't sell to the experimental market here in the US.

It's not that Continental won't sell it... they don't want to sell it direct to end customers, or rather the German division that runs the CD line operates that way.

They want to sell and support it through OEMs.

I talked to Rian at Osh about it because I wanted a CD-155 for my RV-14 and he said that they had talked to Continental about it but they don't see it as economically viable because a CD-155 is $90k. And why would anyone buy the CD-155 for $90k when you could get 2x IO-390s for the same price?
 
Oh well that changes things - my mistake entirely. I thought Continental actually wanted to, you know, SELL the engines. That apparently is not the case.

Yeah, I even tried to sign up for their 5-day CD maintenance class and they wouldn't let me.

Apparently there is some contention between the Germans and the Americans at Continental. At Osh I tracked down the one dude that knew about the CDs and he basically said that the Germans run that whole line and they can't really do anything about it even though the sales dudes would love to sell them.
 
The product looks great, but they need a realistic selling price. $580/horsepower is well into giggle territory.
 
Having worked for a similar International company myself, I will say this market comprehension, related commercial approach, and collegial relationship sounds very familiar. There will be no market for this powerplant in a truly open market. The main advantages are fuel type and BSFC over decades old powerplant designs. Airframe STCs/mods for Mogas further shrink the aforementioned open market. I can buy a lot of xxGas for the left over $50K. I haven't looked further into this PP but I would doubt there is much field repair-ability and OH options are probably only through the OEM or a very finite authorized network decreasing product availability versus the legacy PPs. Did I mention market comprehension?
 
...they don't see it as economically viable because a CD-155 is $90k.

$580/horsepower is well into giggle territory.

Yes, these GA diesel engines are laughably expensive. To paraphrase Luke Skywalker, you could almost buy a whole RV for that.

However: Take the difference between the price per gallon of Jet A and of 100 LL (a couple dollars?), multiply it by however many GPH your RV burns, and multiply that by 2000 hours, and you'll see that in the end, the total cost might be comparable. The premium that you pay up front for a diesel engine is comparable to what you save in fuel over 2000h of flying.

(I'm not saying I'm doing it. Just pointing out that the price is not as outrageous as it first appears, once you add things up over the life of the airplane).

Is the engine featured in the Op’s video a modified automobile engine? If so, what make/model?

According to the video, the engine is based on the one from the Mercedes A200/W169, and was initially adapted for aeronautical use under the name Thielert.
 
Take the difference between the price per gallon of Jet A and of 100 LL (a couple dollars?), multiply it by however many GPH your RV burns, and multiply that by 2000 hours, and you'll see that in the end, the total cost might be comparable. The premium that you pay up front for a diesel engine is comparable to what you save in fuel over 2000h of flying.

Nope - not when you have a TBR (time between REPLACEMENT) instead of a TBO.

Let's call it 2000 hours - times 8 gallons per hour - that's 16000 gallons over the life of the engine. With the difference in price between this and a Lycoming IO360 (which is very generous, as it's comparing 155hp to 180hp) sitting at $50,000 - then you have to save over $3 per gallon on the Jet A versus 100LL. I don't know about you, but most places in the US I see, the difference is more like 50 cents per gallon. That effectively takes the entire US market OUT of the available pool - which limits you to Eurasion countries where 100LL is not available at all, or stupid expensive - but that's only about 29% of all airplane owners total, further cutting down on the market.

This is doomed to fail as an excellent idea with very poor execution.
 
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Nope - not when you have a TBR (time between REPLACEMENT) instead of a TBO.

Let's call it 2000 hours - times 8 gallons per hour - that's 16000 gallons over the life of the engine. With the difference in price between this and a Lycoming IO360 (which is very generous, as it's comparing 155hp to 180hp) sitting at $50,000 - then you have to save over $3 per gallon on the Jet A versus 100LL. I don't know about you, but most places in the US I see, the difference is more like 50 cents per gallon. That effectively takes the entire US market OUT of the available pool - which limits you to Eurasion countries where 100LL is not available at all, or stupid expensive - but that's only about 20% of all airplane owners total, further cutting down on the market.

This is doomed to fail.

Remember, the BSFC for a diesel is better than for a traditional spark engine. Maybe 25% better, depending on who's lyin' the most at any given time.

So, maybe you're saving $0.50/gallon x 6 gallons and $5/gallon x 2 gallons every hour. So $13/hr. And maybe no sparkplugs, plug wires, magnetos, etc. to replace or spend labor maintaining.

IMO, Aero diesels are not a dead-end. They may not be an outright win here, but there are advantages.
 
...most places in the US I see, the difference is more like 50 cents per gallon. That effectively takes the entire US market OUT of the available pool...

Fair enough. However, in many places in the world, the difference in price between Jet A and 100LL is more substantial, and/or 100LL is very hard to find. I think that's the main driver for these engines. I agree that in the US, it doesn't make a whole lot of sense.

And, yes, good point about how getting to the end of TBR is a little more expensive than getting to the end of TBO.
 
IMO, Aero diesels are not a dead-end. They may not be an outright win here, but there are advantages.

To me the advantage of the diesel is being able to go to ANY airport in the world and filling up with JET-A. Heck, it doesn't even have to be an airport, I can go to any gas station and get Diesel.

I can't go to any airport or gas station and find AVGAS.

The fuel availability is worth the money for the engine because I can truly travel anywhere... if Continental would ever sell the engine to me.
 
Using rough numbers for my home airport. Jet A is $1.30/L. Avgas is $2.00/L (if they have any). 6gph of Jet A vs 8gph avgas over 2000 TBO/TBR is ~$15,000 difference in fuel cost over the engine life.

Still not enough to justify a $90,000 engine, not even close.

I'd love to see an economical GA diesel engine. Just that the CD155 isn't it, not in North America
 
Using rough numbers for my home airport. Jet A is $1.30/L. Avgas is $2.00/L (if they have any). 6gph of Jet A vs 8gph avgas over 2000 TBO/TBR is ~$15,000 difference in fuel cost over the engine life.

Still not enough to justify a $90,000 engine, not even close.

I get about a $60K difference:

6 GPH of Jet A @ $1.30/L x 2000 hours:

3.8 L/Gal x 6 GPH x $1.3/liter x 2000 hours = $59K

8 GPH of 100 LL @ $2/L x 2000 hours:

3.8L/Gal x 8 GPH x $2/L x 2000 hours = $121K
 
Discussions in isolation about fuel savings with the Continental CD-155 are pointless. One needs to look at the big picture.

The CD-155, which is basically just an auto conversion based on a Mercedes Benz diesel engine has relatively extreme maintenance requirements that include:

1. TBO on the gearbox of 900 hours
2. High pressure pump life 600 hours
3. Alternator life limit 600 hours
4. Dual mass flywheel testing 1200 hours
5. Fuel, oil and cooling lines replacement 60 months.

The engine has a service life of 2100 hours....but that is NOT an engine TBO of 2100 hours.....it's a full replacement time. The engine is effectively throw away at 2100 hours.
 
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If it's truly a "TBR" vs. a "TBO," then the lifetime fuel savings needs to be far more than the capital cost difference between the engines at first purchase. It also needs to cover the difference between buying a new engine at EOL vs. overhauling the one you already have.
 
Our utilization is also VERY low. Flying 50 or 100hrs a year, the fuel cost is very small compared to purchase/building cost. Spending $50/hr vs $25/hr fuel cost is peanuts when looking at a 40 grand engine vs a 90 grand engine. I simply can't afford to spend 90 grand on an engine, but $50/hr in fuel isn't a big deal. The situation will look very different in 10 or 20 years when the engine needs to be overhauled/replaced.

If I were running a commercial business that flew 1000hrs a year, I'd be more willing to do the math on purchase costs, lifetime fuel and maintenance costs.

Thanks for fixing my math Kyle.
 
Discussions in isolation about fuel savings with the Continental CD-155 are pointless. One needs to look at the big picture.

The CD-155, which is basically just an auto conversion based on a Mercedes Benz diesel engine has relatively extreme maintenance requirements that include:

1. TBO on the gearbox of 900 hours
2. High pressure pump life 600 hours
3. Alternator life limit 600 hours
4. Dual mass flywheel testing 1200 hours
5. Fuel, oil and cooling lines replacement 60 months.

The engine has a service life of 2100 hours....but that is NOT an engine TBO of 2100 hours.....it's a full replacement time. The engine is effectively throw away at 2100 hours.

Fuel pump, alternators and hoses still need to be maintained on AVGAS engines.

The TBR isn't as big of a deal as it seems, and honestly, I kind of prefer the approach. It's not a brand new $90k engine at TBR, it's $45k for a factory replacement engine. Continental ships you the replacement, you unbolt the old engine, bolt the new one on, and ship the old one back to Continental. Replacement complete in 1 day. Almost 0 downtime vs who knows how long its going to take for an overhaul on a Lycoming.

And yeah... you're not doing a condition inspection on it and running it for 4000 hours like Mike Busch likes to recommend, but it's a risk management based approach designed to make sure you always have a working engine.

1 unplanned maintenance event costs enough to offset any savings you may have gained by assuming that the Lycoming required any less maintenance.

The $45k replacement is definitely competitive when you factor in fuel savings, and it's competitive with getting a factory replacement Lycoming.

It's also competitive when you factor in the markets outside of North America where your choice of flying pistons is the cost and logistics of importing AVGAS or using a Diesel / JET-A powerplant.
 
One thing

“…It's also competitive when you factor in the markets outside of North America where your choice of flying pistons is the cost and logistics of importing AVGAS or using a Diesel / JET-A powerplant…”

Probably the only thing that matters to most of the folks seriously looking at the current diesels…
 
To me the advantage of the diesel is being able to go to ANY airport in the world and filling up with JET-A. Heck, it doesn't even have to be an airport, I can go to any gas station and get Diesel.

I can't go to any airport or gas station and find AVGAS.

The fuel availability is worth the money for the engine because I can truly travel anywhere... if Continental would ever sell the engine to me.

Many small airports in North America you'd operate an RV into don't have Jet-A but most have Avgas.

The cruise (where we spend the majority of the mission) BSFC differences between SI engines running LOP and the current crop of 4 stroke aero diesels is only about 10% in reality. I did a detailed comparison in one of my videos. TAC also did a comparison a few years back and it came out at near a wash over 2000 hours in North America (2016). https://www.aviationconsumer.com/aircraftreviews/aircraftstepups/diesel-reset-improved-economics/

Gas stations have Mogas which you can operate your Lycoming on just fine too, as many are already doing if you want to save on fuel costs.

Diesels make sense where Avgas fuel costs are high or availability is limited, otherwise, initial engine costs make these a more expensive choice over the life of the engine. Remember, you get to keep that saved initial money and could invest it for that 10-20 years it takes to get to overhaul which would pay for it.

The WAM had some technical issues which made it more expensive to operate per flight hour than a comparable O-235. Not sure if they've fixed those now.
 
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Nothing wrong with E10

The silent majority of us use mogas E10, nothing wrong with it.
But this is a diesel/engine thread so I'll double down on the apparent lack of any pros such an engine/fuel combination would present.
Given the initial cost and all the aforementioned calculations and perceived savings of the CD-155, it is a giant net loss in all respects.
Not to mention the fact that you absolutely can't get one of these at least not here.
Like everyone else, I do like to kick these ideas around too but for the life of me I can't find a benefit to anyone who has access to 91E10 mogas.
The cost of adapting a fuel system installation to run Mogas is perhaps a couple of hundred dollars plus significant savings to run it. The cost of installing a diesel engine like the CD-155 appears to be an extra fifty thousand and realistically a few dollars in savings to run it.
My hat is off to those who keep trying and experiment with new power plant installations, no guts no glory!
 
are the 90k$ solely for the engine or is this the price for the retrofit package including the propeller, engine mount, instruments, etc.......?

As a turbocharged (diesel) engine, the power output is maintained up to a certain altitude(flatrated). One should either see some better performance with the same fuel burn at altitude, or less fuel burn with the same performance as compared to a normally aspirated O-320 (which is a common engine for the -9),no?

Maybe the engine is not primarily aimed for the US market. On this side of the pond you easily pay around 8$ (europe) and more per gallon of AVGAS, so the whole calculation is different over here (break even is much earlier).
I would consider the maintenance you have to do (hoses, alternator,...) as comparable to Lycoming engines. I know a lot of folks who replace their hoses as well on certain intervals.
But, as it is a diesel, you completely lack the ignition system!
No Mags, no harnesses, no spark plugs (--> less components to fail).

With the flat rated power output i would see the perfect market in hot&high environments.
Add the availability of AVGAS compared to Jet-A/Diesel at remote places as in ...e.g. the outback of Africa....the single lever control, less components to fail, the financial break-even point in closer reach due to AVGAS price over here (i don't know the current AVGAS price in Africa) and i see it as a viable choice for an RV-9 in Cape Town, SA.

After all, it is still EXPERIMENTAL aviation........radials in an -8, diesel in a -9....i have the most respect for the people who are doing this.

@ruans
Good luck with the installation!
Please keep the reports coming.
 
Some aero diesels require the replacement of the turbocharger at half time. Injection pumps (3 times in the case of the CD engines) before TBR. Same goes with alternator, various gearbox parts etc. Lots of inspections set in the maintenance schedules compared to Lycoming engines. These incur substantial costs.
 
Hi all,

Thank you all for the responses. I am overwhelmed by the replies and debates. I did not think it would become some hot topic.

Just for clarity, I do not own this aircraft. I am only filming as I have an interest in this project. I personally would like to see more diesel in GA due to above comments that Avgas is hard to find in some parts of the world.
I am personally concerned about GA. Avgas might be full up in some parts in the world but, for how long? I would rather let the development and research happen sooner than later.

I do understand that there are costs and I unfortunately do not have the numbers. Maybe an idea for a later video to look at some of the real world costs.

I noted in some replies, that the engine is not sold to the experimental market and that is correct. It is to OEM clients only at this stage. The RV-9 being built by Robin Coss will be a production built aircraft. This development will add additional options to the current production built Vans RV range.

I will not be replying on here often as I would like to keep some content for the videos but, I am still reading all the replies.

Feel free to continue the discussion :cool:
 
The TBR isn't as big of a deal as it seems... It's not a brand new $90k engine at TBR, it's $45k for a factory replacement engine.

Interesting! That is a key piece of information (which I did not know), especially given that $45k is competitive against a new Lycoming.

I noted in some replies, that the engine is not sold to the experimental market and that is correct. It is to OEM clients only at this stage. The RV-9 being built by Robin Coss will be a production built aircraft. This development will add additional options to the current production built Vans RV range.

I could be wrong, but I think that most VAF folks live in countries where there is a clear line between factory-built airplanes and homebuilt experimentals. There are enterprises that come close to that line (e.g. A&Ps that will "help" you by doing 49% or more of your build, but work with you to document things in such a way where you can show that you did 51% of the work... and companies that build S-LSAs using manufacturing standards that are not quite up there with Cirrus or Cessna, closer to what you see in an amateur homebuilder's garage) but they're still clearly either "homebuilt/experimental" or "factory built". The line between them remains clear.

So it may be odd/interesting to most people in this forum that, in many countries, there are companies that truly and legitimately straddle this line, building RV-7/8/9/10/14s but being treated by other companies like Continental (and sometimes by local governments) as an "airplane production facility" akin to how Cirrus or Cessna would be treated. So I thought it might be worthwhile to lay this out explicitly for everyone. (In fact, Ruan, I'd be curious to watch an interview with Robin Coss where he clarifies in what ways his business is like an individual amateur homebuilder and in which ways it's not. A lot of VAF users might appreciate something like that).

I am personally concerned about GA. Avgas might be full up in some parts in the world but, for how long? I would rather let the development and research happen sooner than later.

I think that's true for most of us, at least when it comes to the inevitability of 100LL eventually going away. (Having a "low-tech" engine might sound like a negative, but on the other hand, we all certainly value reliability).

I'm personally very interested in this topic because we need figure out carbon-neutral flight, and alternative fuels are the best way to do this: Electric airplanes have serious limitations, and hydrogen has a lot of unknowns. Synthetic fuels, on the other hand, require little to no changes to current airplane. The main reason why I hope that these diesel engines succeed in the market is because you could then use SAF (i.e. synthetic jet fuel made from biomass rather than from petroleum). However, due to the cost, I still think that synthetic UL91 or maybe ethanol are more promising solutions. But if I were to get one of these engines, my reason would be so that I can use SAF and fly carbon-neutral. That would be pretty cool. (Not worth $90k, though, especially since there are cheaper ways to accomplish carbon-neutral flight, some of which can probably be implemented on our good ol' Lycoming engines).
 
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While Jet A will have greater demand, Avgas and high octane gasoline aren't going away either. Might not be 100LL, or other 100 octane variant. There will always be a 91 or 93 octane gasoline spark ignition fuel available too. There will always be something for a Lycoming to burn, maybe not with 10:1 pistons, but 8.5:1 can burn 91 octane with the correct fuel delivery system.
 
(In fact, Ruan, I'd be curious to watch an interview with Robin Coss where he clarifies in what ways his business is like an individual amateur homebuilder and in which ways it's not. A lot of VAF users might appreciate something like that).

Valid and noted point. I am unclear how different the rules are per country. I know there are some differences that I won't go into detail as I am no expert so might give the wrong information.

On my channel I made a previous video around his shop but, does not go into detail as much. You can you check it out if you want to although, it might not answer it directly.

I will ask him to clarify the above. In fact, the next video updated will be based on all the PMs, posts and emails I have been getting and will add this one to the list.

We are awaiting the engine mount anyway so not much progress on the engine side but, there are some updates with the rest of the build as well. So next video I will focus on more on the questions.
 
I've lost my mind...

Lately I've spent a lot of time designing a hangar home. So here's a nice video with cool engine stuff and what am I looking at? Check out the interesting asymmetric truss structure in that hangar!

I return you to normal reality....;)
 
Competition

The product looks great, but they(Continental) need a realistic selling price. $580/horsepower is well into giggle territory.

If VW could be motivated to enter the AC engine market , I suspect the price would drop considerably.
 
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