Gabe used his own as I only sent him the turbine with no electronics. I'm just now taking a look at my fuel lines and checking everything. Just at a glance, when I pulled the lines off the shut off valve, I couldn't really see through it. Also, as far as the pump is concerned, I'm assuming it's a 400. There are no markings on it other than the "Flight Works" label. How do you determine which pump it is?
Thanks,
Steve

The 400 series pump is considerably larger than the 200 series. The 300/400 series pumps are cylindrical whereas the 100/200 series pumps have a sort of rectangular shape to them..... See here for the differences: http://shopping.netsuite.com/flightworks

If there is any sort of restriction in the line at all, beit upstream or downstream of the pump, you'll find it somewhat difficult to get max rpms, if you've seen inside the solenoid valves you'll understand what I mean, hence the need to be anal with your filtering. If the fuel lines and/or fittings look to be in poor shape, it may be prudent to replace them.

Hope this helps.

Cheers,
Smithy.

My pump is cylindrical so it's a 400. I think I found the problem. The plastic piece in the fuel shut off valve was very restricted. One side of it was drilled to the same diameter as the hole in the barbed nipple and the other side looked like it had not been drilled at all. It had a slit cut in it. I'm very surprised that the fuel was able to make it to the engine. Now I can see why my voltage was high at full throttle.I drilled it out and now I can blow through it with no restriction. I'll run it again tomorrow to see what I get. I'm sure I'll achieve full rpms now.
Steve

Definitely sounds like the culprit ! let us know how it runs.

Now that the JJ engines have been in production for several years, what is the most time/cycles anybody has seen on one?

Good question! I've asked numerous times myself. Lets see if you get any answers.....

email Gabe he has been flying like crazy

Hey Dave,
I have a JJ1800 which I purchased not too long before Christmas, It's essentially used as a testbed work horse. I've been running it for quite some time using different fuel and oil combinations trying to find a happy medium, I've found that these engines will run on just about anything that will burn, that being said, the best combination I've found seems to be the good old Jet-A1 with 4-5% Mobil Jet 2, this creates less of a carbon build-up than using other fuels such as diesel and synthetic 2-stroke oils.

My engine has just a tad over 27 hours on it so far, (1622 mins), my HDT indicates 173 cycles, that's an average of ~9.4mins per cycle, all this on the same set of bearings too. The bearings are due to be replaced very soon though as they are getting a bit tired. I have run it for up to 25 mins at a time at various rpm settings with no ill effects other than disturbing the neighbors with the noise!!

My engine doesn't see any runways since it's not mounted in a model aircraft so the ingestion of dirt and dust is minimal compared to most of you, I suspect this is why the bearings have lasted well. It's basically just a testbed for my afterburner system and will eventually see service in a 1/5 scale jet dragster.

Cheers,
Smithy.

" My engine has just a tad over 27 hours on it so far, (1622 mins), my HDT indicates 173 cycles, that's an average of ~9.4mins per cycle, all this on the same set of bearings too. "

I'd say that was a pretty strong endorsement for a very well made engine, wouldn't you Mr. Rigotti ? Or are you back permanently to bash this turbine some more ?

> Jim

Clearing the shut off valve fixed my problem. I ran the engine and it has unbelievable power. I'm getting 116,100rpms consistently. I have to do some adjusting because when I went from low throttle to 1/4 throttle, I got flames which tells me there's too much fuel being sent to the engine. I'm so happy now. I can't wait to fly my Mig29. Thanks for all of your help,
Steve

Hey Steve,
Great result, you may not have to adjust anything, do a normal TX range adjustment and then take the engine up to max rpm from idle slowly, then back down to idle slowly, do this a few times and take about 15-20 seconds each way..... it will give the ECU a chance to learn the new fuel pump requirements, after a few slow runs up and down, you'll be surprised at how well it behaves. Remember, the ECU was used to trying to pump a heap of fuel due to the blockage, once it learns the lower fuel requirements it should behave normally.

Cheers,
Smithy.

It looks like you should buy one and get it in the air Mr. Lynch-Could always use more turbine pilots.
PS Smithys results would be the same as having Bob Wilcox running and testing at Jetcat. Not really average joe real world users. Scott

Quite right GSR, I don't think we can use this as a "real world" test senario, as soon as we see somebody with a sustantial amount of hours with "real world" operating conditions on their engine, we may be able to talk about it at length.

However, I've had pretty much flawless operation from my engine and I can't complain at all, also, running the afterburner puts a substantial amount of extra strain on the componentry for which it was not designed.....so a big thumbs up there!

Cheers,
Smithy.

I never left...

How many trouble free hours you have on your JJ? Hmmmm?

ANY others out here?

Now If I ever want to turbinize a Black and Decker Workmate, I know where to find a possible candidate!

Dave

Dear JetJoe Experts,

I bought a JetJoe 1800 this past summer and had a mishap before getting it airborne , sent back to Mark and did a great Job fixing it ; I finally Got it and mount it on a Rookie with a flightworks pump . The Gas Solenoid sometimes gets stuck but opens with a tiny tap with the screw driver and engine starts flawlessly. The RPM reached at Max throttle (on ground) is 115100 ; When I got it airborne in the test flight , I noticed a very weak thrust and had to keep the throttle at MAX to keep the plane flying till just before landing . The Engine is rated at 20Lb but I know this may change depending on a lots of factors but should not be severly underpowered; It was behaving barely like my JETCAT P60 at best . I will check my Fuel lines ...etc... but the MAx RPM is reached yet with weak power. Any suggestions ? Thanks. I am using Jet 1-A with Mobil Turbine oil 5% mixture ; Battery is 2 Cell Lipolymer at 4000 mAh with good voltage not below 7.5v at max RPM. Thanks again.

Anyone?? I have no idea. Very curiuos also why so under powered, yet at full RPM....

Hey DrGsi,
Are you able to give us some info?, EGT's at idle and full noise, pump PW reading, relative altitude, ambient temps etc... might be helpfull in helping diagnose the problem.

Cheers,
Smithy.

Ran my JJ1400 a few days ago on a breadboard setup. First 2 starts were flamers, due to opening start gas valve way too far.

Here's a link to the 3rd run, idle at 40,000, full speed was 160,450 RPM

It'll be in my Super Falcon soon!

http://video.google.com/videoplay?do...49901362&hl=en

THANKS,

Idle RPM 32000 ; EGT at Idle 450 Deg ; MAx RPM EGT 590 ; Smooth running at max RPM ( No overheating problem) ; Ambient Temp in Saudi at time of test was 80 Deg F; Altitude of airfield 700 meters above sea level dry weather (10% humidity) . Things that I will change first is to put the airtrap closer to pump ; The airtrap was placed next to nose gear with fuel line coming forward from tank then backwards to pump (placed at CG) then back to Engine. The distance appears to be quite long for the fuel travel ; But if that is the reason, I should not achieve full RPM , right ? Yet I will cut down on fuel line length and check it next weekend. I can't think of something else ..All filters are brand new and clean . Could the fuel solenoid be acting Up ? It shouldn't be with a smooth start and great response to throttle stick ! We will see...... I'll get back to you next week.

Hmmm, All seems to be in order, there's plenty of temp margin too, you're right about fuel line restriction, if there was a problem you wouldn't see max rpm. Are you able to measure the tailpipe exit diameter?

I believe the nominal tailpipe exit size for the JJ1800 is ~54mm, it may be possible to go a little smaller, this will help a little with thrust but at the expense of higher EGT's, but again the thrust gains will only be very minimal. This is a strange one, most of the 1800's I've seen have all been over 18lbs @ sea level.

Exit Diameter 54 mm exactly . I'll see what happens with less fuel lines and get back to you guys. Thanks again.

If you are getting the full RPM, less fuel line shouldnt make any difference.

Hi guys,

I have been following this thread with great interest. I am primarily a glider and electric pilot and am contemplating getting a turbine. I have been to a few jet meets in OZ and like the smell and the Speed!! Only problem is to fly there is a min 2 hour travel from Sydney. Even though this is the case for me, I am thinking if I flew at say 2 to 3 jet meets a year this would keep me happy

Now I am contemplating the JJ1800 in a Fly Eagle F16 and would welcome any comments??????? Unfortunatly everyone I have spoke to sais stay away from JJ turbines???

Yes this is my first post, so sorry if off current topic.

Cheers,

Mav

Hey Mav,

Whereabouts in Sydney are you Mav?? I have an 1800 you can see in action, unfortunately it's not in an aircraft but it'll give you a good idea of what the JJ's can do!!

Cheers,
Smithy.

(means help is far away?)

and


You might want to listen to those people.