AndyAndrews

On Kingtech Turbines, owners can use automotive grade diesel without voiding the warranty. In fact Kingtech encourages it. Why can't we do the same with other turbine manufacturers? Is there something that Kingtech is doing that others are not that enables the use of diesel?

Just curious.

Andy

cy paul

I thought i read somewhere also that behotec turbines can use diesel...

grbaker

My Feedback: (29)

Neither of my turbines are under warranty any more, so I decided to give diesel a try. I have been running diesel exclusively for about 6 months, now in a JetCat Titan (one of the early ones) and a Jets Munt Merlin.

I may regret it some day if I experience maintenance problems down the road, but I doubt that I will. The only thing that has been disappointing for me running diesel is that I was hoping for a slight black smoke trail in the exhaust. There is not even a hint of smoke with the new low sulfer diesel.[&o]

AndyAndrews

have you tried ag diesel?

ira d

I read somewhere not sure whereit is because Kingtech uses a stainless steel combustion chamber and most others use inconel, The diesel has some
type of reaction with inconel that degrades it.

rcguy59

My Feedback: (8)

If that's the case, (and I don't know that it is) what about the turbine wheel? It's also inconel. Perhaps the diesel has burned sufficiently at that point that it's not a threat to the wheel? I hope someone out there can explain this to us, as diesel's availability is about as universal as it gets and being able to safely use it would be a boon.

ira d

I think also inthe info I read it was somthing about the sulfur in diesel being the culprit, Im sure some of the turbine reps will chime in on the subject.

hooker53

My Feedback: (106)

Thats confusing because in the past when I ran a machine and fab shop all my metal suppliers told me that the only Diff between the two was that Inconel is still in the SS family but was for a much higher heat range. I'v bought and worked with both. I bought and used thousands of pounds of 304 and 316 SS.

nxtdoor

My Feedback: (10)

I use to sell stainless and inconel. Inconel has better resistance to sulfur than stainless. It is used for burner buckets (where the coal is burned) in coal fired power plants because of its sulfur and high temp resistance. Its also 5 times more expensive. Diesel should not be an issue with inconel. It is probably more to do with residuals build up in the combustion areas of the turbines.

Jeff

SinCityJets

With the right software and programming, they COULD all burn Diesel. The real problem is, at our operating temps, diesel does not produce the same energy as kerosene (or Jet A, JP-??). Because it doesn't, you need a complete reprogramming for start-up and running.....not to mention Kerosene burns a lot cleaner.

Can they do it? Yes
Are they all programmed to do it? NO

For a people in places or countries that don't have a lot of access to Kero, you make the best with what you have (burn Diesel).....for people that have easy access, stick with the Kero. You'll be glad you did in the long run.

Chad


Corrected for Mark's post below!

noahb

My Feedback: (67)

....

causeitflies

Diesel has more BTUs than kero so it has more potential energy. It is also higher in sulfur content. It will be slightly harder to vaporize than kero.

SinCityJets

Mark,

You are correct, I should correct it...at the temps our turbines operate, the kero produces more energy.

Chad

lov2flyrc

My Feedback: (24)

Not from the tests I have done. We actually see a half to one and a half pound thrust increase on diesel over kero depending on the engine. No major ecu changes on the KingTech engines between fuels.

SinCityJets

Wow, I am really surprised at that! What do you consider "no major ecu changes"? I know it is not as simple as just changing the fuel.

Chad

ira d

I have a Jetcat P80 one time I went to purchase some bulk fuel in two containers when I returned home I found the the fuel in one contanier looked and
smelled like kero the other one looked and smelled like diesel and was a darker color. What I think happened was they ran short on kero and desided
to subsitiute the diesel and im convinced the can had little or no kero in it. Anyway being curious I put some of the diesel in my plane and the engine
started up and ran ok but I did notice more of a poping sound as I dont think the diesel was buring as completely as it should.

In the end I used the diesel as weed killer but I dont see any reason why any of the model turbines wont start or run on diesel they just may not run well
of course if it is a kero start that maymake a difference. I cant find the info I referred to before about the stainless and sulfur but im sure I read it somewhere.

Henke Torphammar

A well running engine = happy customer. Recomending Jet A-1 with the same 5% shell oil makes sure every one on the planet uses the same sort of fuel. Same fuel equals less margins in, still in a safe matter. I bet you all know about chip tuning for cars and that they deliver more power on higher octane fuel when the ECU is tuned. If you know exactly which fuel you are running alot of parameters in the tuning can be set closer to the limit.

I do not know the exact diffrences between diffrent dieselbrands, but I know there are quite big diffrences in power output between diffrent brands, just as with diffrent octane petrol, so just saying it will run on "diesel" might not be the full story.

Gaspar

Hi,

We, at JetsMunt, have tested our engines using diesel, biodiesel30 and 100% biodiesel.

From the engine durability point of view, there isn't any issue to use diesel, we have costumers using it, specially a german costumer who is allergic to kero. It can be used without any ecu tunning, IF the ambient temperature is mild, say above 15ºC.

End power output is exactly the same, power just depends on engine massflow and pressure ratio, fuel consumption is a bit higher, specially at low power settings due at the higher vaporization temperature that make the combustion less efficient at low power (low chamber temperature), and finally, the pump must work harder to pump the thicker fluid. On practical side, the diesel stinks, the engine smokes a lot of white smoke at startup and at shutdown, really messy. On low ambient temperatures, things are more complicated, the diesel is much thicker, so startup is more difficult, and sometimes the acceleration from idle to 1/4 power is unstable, in these cases could be necessary to increase the acceleration time. In all cases, diesel is only noticeable at startup and up to 1/4 throttle, from there the performance is the same.

So, on JetsMunt engines is possible to use diesel, but as Henke commented, we recommend to costumers to use the fuel that we know that is better and more predictable. As a company, it is not wise for us to adjust the ecus to accelerate the engine in 6 seconds to cover the possibility of a costumer using a unknown diesel in a unknown ambient temperature, where the very same engine accelerate in 3s in all weather using kerosene.

Hope to have clarified our point of view on this issue.

Gaspar
JetsMunt Turbines

willig10

I am an A&P and have worked on (maintained) jet engines for 20+ years. Of course on the full size engines like the F100, CFM-56, PT-6, CF-34, T-33 etc. All of these engines come with a placard as to what fuel they canuse and for how long. The fuels that can be used vary from Diesel, gasoline (Mogas),JetA, JP4 etc. In fact most if not all turbines are very tolerant of any liquid fuel. That said.

I am not familiar with what material Jetcat or others are using but I would venture a guess and say they are using inconnel or very similar materials.

When we used to get an airplane in for a heavy maintenance visit, we would defuel the plane and put the JetA in our ground support Diesel equipped units.

The benefit of using kerosene over diesel in a Diesel engine is that the Kerosene has a low or no oil content in the fuel and is very clean burning. Diesel fuel has oil in it which when run through a Jet engine causes an oilresidue build up, in the turbine wheels and bladesand will cause corrosion in the hot section eventually.

When you take a jet engine apart (full scale) that has ran diesel you will see a greenish sulphur buildup on the turbine bladetips. If this is left alone and not cleaned it leads to turbine wheel Blade failure if enough hours are puton the engine. I used to have some pictures of a CFM56 (Boeing 737) engine that had catastrophic engine failure for just this reason.

I am not sure if this would be an issue on smaller turbines that we use for RC purposes. Also if memory serves you guys have your engines inspected every 25 hours or so, am I correct?

If your engines are being inspected at that interval, I dont see you ever having enough buildup to become a problem.

The full scale engines have inspection intervals at roughly 2500, 5000, 7000 hoursand some are not "HARDTIMED" as long as a borescope inspection is performed and no internal damage is found or FOD issues.

Dont know if this helps but if your engines are using the same hybrid materials as the full scale and you are tearing the engine down every 25 or so hours, I believe running diesel would pose no problem for you.

Glenn Williams

highhorse

My Feedback: (2)

Interesting, but remember when discussing the full scale issues: those engines might get more hours in one flight than most of these turbines get in an entire season, and run more hours in a week than these will turn in their lifetimes.

grbaker

My Feedback: (29)

I realized I had just enough kero for one flight and really wanted to fly my JetCat Titan powered Facet2300 all day. So I put a quart of Aeroshell 500 in an empty 5 gallon can and stopped at a gas station on the way to the field and bought 5 gallons of diesel. I expected to see some changes in the way the turbine ran and I expected (and hoped) to see a smoke trail.

I flew the first flight on kero and the other 4 flights on diesel. There was no discernable difference between the 2 fuels. I couldn't even smell the difference when it ran. I was very dissappointed when I saw no smoke. The only time it smokes is on shut down and even then it is very little and not every time.

Reading Gaspar's post makes me wonder if I may be playing with fire here, especially when flying in cold weather (of course it does not get cold here very often). May have to take another look at the whole thing.

marquisvns

This is totally false. KingTech Turbines uses nothing but inconel.

Barry

marquisvns

Chad, it is as simple as Todd stated,"no major ECU changes" with KingTech E series (propane start) turbines to use diesel. At the most, maybe a little more aggressive on the delays.

Todd's finding concurs what we have at the factory 3 to 5% more thrust with diesel. I think this KingTech diesel compatibility - all comes down to the design of the engine, the efficiency of the combustion chamber. Everything gets burned up and blown out the back, while others may or may not.

I am still tweaking our F series to be started with diesel. Out of the box, F series are plug and play with kero, but diesel is an entirely different story,.... to be continued.

Barry

ira d

In another fourm I read in a discussion about the K80 when it first came out that the combustion
chamber was said to be stainless it did however say the vaporizer sticks were inconel.

If that post in the other forum was in error I apologize but I never did see in of the Kingtech reps
who post there refute that info. If however Kingtech has changed to inconel combustion chambers
in later production runs then my post was not totally false.

fred985

there is so little sulfer in LO-SULFER diesel it dosent matter. ag diesel and homer heating oil is the same. i would use kerosene myself. it is much cleaner,,but would still filter it. inconel is one of the tufest metals the is,,,disel sure wont bother it.