I am having a problem with a K 80G that will only go up to 141 Max RPM setting in the ECU. The engine is only a year and a half old just purchased used with less than 5 hours of run time. I have a new K 80G purchased in May of this year, it has not been run. I checked the settings in the ECU and it does go up to 145K.

I Called Barry this morning and he told me he would not program the ECU to reach 145K because of safety issues. Barry also told me K 80's are 80N class turbines which equates to only 17.89lb of thrust which is just shy of 18lbs.

The specifications clearly state
Thrust: 8618 g @ 21.1° C. (19 lb. @ 70° F. )

Is King Tech representing K80 series engines as 19 lb thrust engines, when they are really 17 lb thrust engines? If this is the case we have a serious problem with them not being truly honest or sincere by providing consumers with false information. It clearly states in the owners manual and the King Tech website the K 80 is a 19 lb thrust engine.

Is there anyone else having this issue?

With my car, they advertised 47 MPG. Most folks with that model only got 42 MPG. There was a class action law suit. The manufacture ended up settling for a few bucks to each of us. But the settlement was nowhere near the difference that we paid for the car to get that extra mileage. Bottom Line the manufacture is going to do what they do. Complaining never seems to significantly change the ultimate resolution.

To your turbine manufacturer's defense, maybe they found out that at 19#s the turbine is not reliable. So they are keeping it back in RPMs to keep the thing reliable. The manuals and ads have probably not caught up with the change. Probably never will. I suspect that is what happened to me when one of the manufacturer's came out with a 90 and claimed it to have a couple more pounds of thrust than the 100. Only things was, I could not get two of the three 90s that I had to reliably start and ultimately the third one would start just fine but it disintegrated internally on its 10th flight. I went back to the older model 100s and everything works as advertised. Now I am back to never buying a "first year production model."

From my experience with the three 90s, I think the industry is highly dependent on us to field test the units and over time, ECU adjustments are made to compensate for what is discovered in the field. Unfortunately, these changes are not forced recalls and are NOT made until someone has a problem or updates the ECU. Based on my experience with my manufacture, the manuals and ads never catch up with any ECU updates. Just my opinion!

Hibbler,

I have an older K80 that is putting out over 20lbs of thrust. I have read in other threads that the manufacturer test runs the engines and tunes them to the thrust they should be putting out and the advertised max thrust is just a that, whether its 139,000 or 145,000. The manual just shows the max RPM the engine is not to go over, not the RPM it is to be set at. I know all my Kingtech's put out more than the advertised thrust and the RPM's vary from what the manual says. I also know that other manufacturers use some kind of formula to calculate thrust base on 15*C temp, sea level, barometric pressure and such, but all my Kingtech's put out the power they say it should. Have you put your engine on a bench and tested the output? Do you know you are not getting the proper thrust at 141,000rpm? Let us know what your real output data is before you cast stones!!

Ghostrider

I agree with Ghost have you put it onto a test bench and seen first hand how much thrust your getting?

The K80G that Howard is referring to was tested, I tested the turbine with the ECU that it came with and the Max RPM is set to 141K it will not go any higher, you can lower it but it will not go any higher......When I ran the K80 the GSU showed a max of 141200. The next test I took Howard's ECU that came with his new K80G. The new ECU under settings, maxes out at 145K. I fire the engine up and there was a significant difference in thrust. The GSU showed a max rpm of 45700. The third test was I took the new ECU, dialed it down to 141K then test ran it and the Max rpm showed 141300. So in conclusion the original ECU was PROGRAMED WRONG. There's nothing wrong with the turbine it's the ECU so no one is casting Stones here...... When I call Berry to try to get the ECU reprogram, he told me it's set for safety reasons at 141K. If that is the case that turbine should never been sold as a 19 pound class turbine because it's only putting out 17 pounds of thrust therefore it's no good to meet for the aircraft that I purchased it for.

Seems to me if Kingtech knows that some of their engines thrust output varies a significant amount while operating at the same RPM they should openly disclose this and avoid the confusion.

Frank,


The engines them self will operate at what ever the ECU tells it to. So using the newer ECU set at 145K will let the older engine run at 145K. The question is, what is the thrust output with the older K80 at 141k RPM? Is it putting out 18-19lbs at 141K RPM or is it only 15-16LBS? I am guessing it is putting out the specified power at 141K RPM and that is why the ECU is locked down at said #. If the engine is producing 18-19lbs at 141 and you open it up to 145K RPM that engine will be producing 100N + range and it is not designed for that much power and that is probably why Barry said it is locked down for safety issues. I have a K-140 that is locked down at 120k RPM and I know it produces 31lbs 12oz per my scale but the manual says the max RPM limit is 123K RPM. If they opened up the ECU to 123K RPM it would be producing 160N power and the engine is not designed for the extra horse power and that is why it is turned down.

I think you guys are misunderstanding about the max RPM's settings. The engines exponentially produce more thrust when you get into the higher RPMs and make very little thrust in the lower RPM's. So, if the factory locked the ECU down at 141k they did it because the engine makes the thrust it is suppose to at 141K RPM. Like I mentioned earlier at 145K RPM it is probably putting out 100N + power. Are you thinking because it is not set at 145K RPM you are not getting the power you should be? I guess I will repeat myself and ask, what is the max LBS output you are getting with your scale on a test bench?

Have you called Dirk at Tech Support for his opinion?



Ghostrider

Ghost Rider, let me make this perfectly clear I'm not here to get into a pissing contest, and I'm aware that the engine will run with, whatever ECU that it is connected too, and in answer your question "was it tested on a bench that measure the actual thrust" well my friend that is a wholeheartedly, "NO IT WAS NOT" now that being said ,it doesn't invalidate the tests that I performed. I've been in this hobby for 34 years, I've been flying turbines for 11 years, I have a variety of turbines from 80 class - 180 class, three different brands, (A total of 8 turbines) and trust me I know what 19 pounds, 30 pounds or whatever the pounds of thrust feels like in my hand so I don't need to use an exact measuring stick in this case.

Ghostrider what you say makes sense but Kingtech should verify what you say if it’s true, the fact they won’t does give cause for concern don’t you think?

But the OP says the difference is between 17 and 19 lbs thrust not 30 and 19. No offense but are you sure you can tell that difference holding it in your hand?

IMHO it is logical that the higher RPM turbine had more thrust, but is that what the complaint is? The complaint appears to be that one turbine is below some low end thrust spec? Or is the complaint that Barry will not raise the RPM?

Also, you appear to be assuming that "old" and "new" turbines with the same name are indeed the same internally. I don't know about Kingtech but I can tell you for 100% certain this is not the case with other brands. Anything can be different internally (or even assembly process, balancing, anything), and in many cases as the turbines get newer the RPM can safely be increased. I want to stress this is not Kingtech I am speaking of.

"trust me I know what 19 pounds, 30 pounds or whatever the pounds of thrust feels like in my hand so I don't need to use an exact measuring stick"

Dude, that's HILARIOUS!!!!! You're a walking scale, HA! Love it.

All turbines put out different power per rpm... We do power assurance checks all the time on full scale engines for this vary reason. RPM is not thrust. It gets you in the ballpark but they are not the same on every engine.

I have seen some K180s put out k210 power and some just 180 power. Differences in the NGV vanes and turbine blades along with the compressor all change thrust.

Yes I already Know there can be some differences but we really need the Kingtech to explain why some of their engines are not at the rated RPM. Like I said if they know some K 80’s can produce 19 lb thrust at
less than 145 K they should say so and certify each engines shipped with the exact thrust that engine produced.

Ok guys,

For the record,

Our factory test runs all the engines before they are sent to the customers. The max RPM in the manual is just that, a not to exceed RPM. Even though each turbine comes from the same parts, no 2 turbines are identical. That's why when a customer sets up a twin, he will have me match the thrust outputs on the test bench to fine tune them. Most every engine I test, usually puts out a tad more than it is suppose to. The Early K-80's had a completely different internals than the current versions. The earlier K80's used a "J" tube injector and the new 1's use needles. The factory made the change to make the engine even more reliable and more fuel efficient. The turbine in question was tested at the factory and the factory intentionally locked down the RPM because the engine was making the proper thrust at that RPM. If they left it higher, like Barry said per the customer, it is for safety reasons you don't want the engine over producing what it was designed to do. The good news about that engine is you are getting max performance and using less fuel, less wear & tear, due to lower RPM.

Hope this helps clear things up?

Dirk
KingTech Service

Dirk Thanks for the reply.

"The factory made the change to make the engine even more reliable and more fuel efficient. The turbine in question was tested at the factory and the factory intentionally locked down the RPM because the engine was making the proper thrust at that RPM. If they left it higher, like Barry said per the customer, it is for safety reasons you don't want the engine over producing what it was designed to do. The good news about that engine is you are getting max performance and using less fuel, less wear & tear, due to lower RPM."

Above information were shared extensively with Hibbler during his phone call.

What I will admit responsible is the conversion and lack of updating of spec sheet on the manual and website. A K-80 is rated at 80 newtons of thrust at 15 Celsius, that equates to 8 kilograms, or 17.637 pounds at 59 Fahrenheit. We set up engine at its rated thrust, not RPM.

Regards,
Barry