airraptor

My Feedback: (66)

Ok thanks I havent had a chance to read through the whole thread yet. setting the preload correctly should be easy or at least i would think so.

as far as the balance goes that one might be a bit harder for me as in the Air Force we have removable blades and we change them out in pairs 180 out.

So 1500.00 for this one with some work or 2,500.00 and not much work for a P-20????

What is the fuel draw on this thing? what is most everone running for tank size? 20 Ounce?

knobby1

The P20 is a much better quality engine, it also is a bit larger and substantially more thrust.

Setting the preload on the Junior isn't the issue, it's the preload wave washer itself which fails, they tend to break into two pieces, needless to say the preload is then non-existent and the engine basically beats itself to death. I have some modifications for the Junior which changes the preload system, shortens the compressor and shaft to reudce the amount of overhang at the front bearing, core balance to under 1mg-in .....seems to work ok so far.

The Junior uses ~80-85ml/min.

Cheers,
Smithy.

airraptor

My Feedback: (66)

Knobby what about replacement washers i am sure someone out there has some that would work. I have a little sapac viper that i would like to put a turbine in. it has been done with the P-20 but i think the P-20 is a bit much for it. The JJJ looks to be in the right power and weight range.

knobby1

Hey Airraptor,
Yes, I guess you could use alternate wave washers, not a bad suggestion at all. They are very small though, and to be honest I've not looked for alternate suppliers. Once the JJJ's have been set-up ok they're not too bad.

Cheers,
Smithy.

Henke Torphammar

Why not go for the Lambert kolibri while at it? The T15 airstart now officially produces 1.9kg of thrust and actually cost the same as the Jetjoe junior, but much better quality as it is the real thing, not a copy. Remember you still have to balance your JJJ when you recive it, adjust the tailcone for proper EGT etc. Perfect for the Frema type of guy but not suited for common people who wants to fly out of the box I think.

Then if you choose a Kolibri or P20 is more up to your own preferences and likeings, however the airstarted Kolibri is alot of power in a tiny package at a low price.... and it works very well out of the box.

Dr Honda

My Feedback: (4)

HU??

In the states... the Kolibri engines are about 2.5 times the price of the JJR. For $1650, I can get a hand massaged JJR engine from Aussie jets. A Kolibri is about $3500.

Without a doubt... the Kolibri is a better engine... but it's very expensive.

SniperWj

because of the selling price of the t25 that make p20 so popular !

the high selling price is some how you can get a 180rx if you top up some more! not to compare
apple and orange just to point it out.

almost bought a t25 but I pay abit more now I'm holding the bigges rx series in my hand.

yiming

Henke Torphammar

If we assume ausjets installs a proper preload, and sorts out the engine so that it provides the promised 4lb of thrust and are ballanced to under 10mg/mm we can make a fair compartion like this:

1578 AUD + shipping of let's say 50 AUD + VAT + customs fee (about in total 30%) = €1700 or $2250

Kolibri T15 equals €1850+ shipping of aout €25 = €1875 or $ 2480.

Close enough to say it's the same :-)

(BTW, both the jetjoe site and ausjet webshow is not working.)

Henke Torphammar

Both Kolibri T20 autostart and Jetcat P20 are rated 24N output, Kolibri T20 costs €2260, P20 costs €2395 (Prices from the manufacturers sites)

You have to compare apples with apples :-)

SniperWj

not another small 2.4n apple henke! t25 tuned up is the only one will make me
spend money after I got my racer with kolm 200IL project complete.

frema

i just let my junior run
i can tell you its not a standard junior.
i ran with the normal ecu so the rpm is only 242k
the temp was 710 and thrust was 2kg, not so bad i thought.

Regards,

Martin.

Felix Barrao

Very nice numbers, Martin ,mine pulls 1.7 Kg @ 245.000 rpm. Temp is 680º at full thortle

jymster

My Feedback: (9)

Hi all,

With Smithy's help, I finally figured out what was up with my Junior. Seems the fuel ring was clogged with carbon. With the ring now replaced with a clean one (thanks Smithy), she is again running well. Will try to post a video at some stage.

James.

chuckels

My Feedback: (25)

James,
that's great news!!
That Smithy is one fart smeller.... um smart feller...
Chuck

jymster

My Feedback: (9)

Hi Chuck,

Yes, it's true! I hope to have the Junior in a model this year, but still a bit tight on budget at the moment. Have to finish off my 97" Gee Bee Y and 63" EPO Corsair first. Then I'm heading over to Top Gun in a few weeks, so that will put a nice dent in the budget for a while!!

James.

idleup1

[youtube]http://www.youtube.com/watch?v=Ju6zlo3xSBg&feature=youtu.be[/youtube]I test ran my junior today I clean the injectors as they had clogged even with a festo filter in line. It runs OK now. acceleration is good, no vibration , preload is good . temp a little warm 730 at 242,000 I may add a propane solenoid as I tend to be a little slow to turn off the gas.

frema

how deep is the egt probe in?
no more then 2mm is good
mine run 650 and i tuned it
it delivers 2,3 kg now with 250 k
no problem

idleup1

my probe is in a little more than 1 mm. I tried 13 to 1 and diffent locations but the temp reads near the same . I is calibrated to 100c in boiling water I have a manual xicoy unit that I can turn it up more than 250k but it has no solenoid controls or glowstart.. I may modify the chamber holes to drop the temp. I have the tailcone opened as far as I care to already.If I run 250k now the temp would be near 800. jj ecu is limited to 242k, xicoy to 252.

frema

oh boy oh boy those poor bearings
please machine your compressor wheel and spinner nut
also change the gap between the compressor and intake , your engine runs to hot
i think the shaft is moving to the back at full throttle
you can see that at the high egt
you need atleast 2kg of preload for good performance

mine have almost 3 , because of the fast accelerating during the run on my tractor
this is not negative comment ,but positive
if you can change all those things ,your bearings will last much longer
i can easy run 250k
and with shutdown , you even hear the bearings.

oke ,goodluck with the junior
if you want help , you can email me

Regards,

Martin.