|
RE: JetJoe OWNERS thread
The temp at max rpm is around 610- 620.
Did your 11lb JJ1400 create more thrust after clearing the plugged needles? How much? My first 1400 had one completely blocked needle and two partially blocked from the factory. I was only able to get them flowing after heating the silver solder at the base and pulling them out slightly. They all flowed evenly then, but I never measured thrust on that engine as it wouldn't run consistently (Joe later told me it was a problem with the rear bearing) and never made it into the plane before I sent it back to Joe for the one I have now. I haven't had this one apart to check the fuel ring flow and stick geometry since it has always ran reliably, except low thrust, which I hadn't measured until recently. Mike |
RE: JetJoe OWNERS thread
ORIGINAL: YLF The temp at max rpm is around 610- 620. Did your 11lb JJ1400 create more thrust after clearing the plugged needles? How much? Mike After sorting the needles and taking care on the rebuild it was reading just over 12lbs taken while in a model on a paved area. The scales were digital, considering the turbine the second time was shunting the model with 1/2 gal fuel and gear on board it was an OK result, though not to GTBA standards. Can you confirm the outer dia of your compressor (at the inlet) is a nominal 43mm with 12 blades i.e the latest version for the JJ1400. Paul |
RE: JetJoe OWNERS thread
Paul,
It does have the 12 blade compressor, I'd have to go measure the diameter. The engine was new from Jet Joe about 5 months ago so I'm pretty sure it is a later model JJ1400. I may go ahead and open it up to check the nozzles etc. Just hope the compressor nut releases before the turbine wheel nut so I don't have to get it balanced again. Also, before I do anything I will measure thrust with it in the plane as it is now and then again after working on it and with the two different exhaust cones so we'll have some numbers to compare. Also Paul, did you have the single or two piece exhaust cones on yours? Mike |
RE: JetJoe OWNERS thread
ORIGINAL: YLF Paul, It does have the 12 blade compressor, I'd have to go measure the diameter. The engine was new from Jet Joe about 5 months ago so I'm pretty sure it is a later model JJ1400. I may go ahead and open it up to check the nozzles etc. Just hope the compressor nut releases before the turbine wheel nut so I don't have to get it balanced again. Also, before I do anything I will measure thrust with it in the plane as it is now and then again after working on it and with the two different exhaust cones so we'll have some numbers to compare. Also Paul, did you have the single or two piece exhaust cones on yours? Mike Dave |
RE: JetJoe OWNERS thread
Mike
I replaced the twin cone and fitted only the single exhaust to the others. There is a question of warranty for you. I don't have any factory warranty as I build my own and yes I know (before others jump in) JJ won't sell JJ1400 kits with few exceptions. I'd really suggest shipping yours back for repair since it is so far down on thrust. Changing the exhaust should be OK but opening it up invalidates any warranty. Dave is right your turbine should be marked No. 700+? Paul |
RE: JetJoe OWNERS thread
Bullet Starter and USB Cable
Joe shipped the new bullet starter which is real sturdy compared to the original. I have recently tested the beta software ver4 and USB cable for the JJ-Nades FADECs. It is a bunus to download the 50+min of running data and view the running parameters when required on a laptop. This software is available free. When I spoke with Andy last year he indicated the major return factor was blocking of needles, since the bearing lube injector is very fine and flows at about 50% of an fuel needle, it is interesting that other manufacturers have increased the flow rate to about 200% more flow than a fuel needle. Following discussions on the GTBA site, this allows lower oil content within the fuel and avoids rear bearing problems. Some will have a JJ as their first turbine, the old jet hands will be familiar with bedding in of bushes and running in their pumps on a loop to filter any fines and rubbings from the gears. Do many JJ owners triple filter their fuel? I use a last filter after the pump just before the turbine. This used to be known problem for the ECUs as any blockage here increased pump pressures and eratic runs. Though obviously if there is no debris this clear filter never collects anything and remains visibly clear. When problems do occur viewing with a mirror can safely reveal the hot spots as unblocked needles deliver more fuel and blocked needles none. The colour of the burnt fuel and viewing the through the NGV gives a good indication of the mixture burn. As can the chambers residual flame pattern marks. This has all been covered before in the mags+RCU maybe like teaching granny to suck eggs, just thought I'd mention I still see jet jockeys breathing fumes and looking up the exhaust with terminal possibilities. Paul |
RE: JetJoe OWNERS thread
hi everybody!
i'm vincent from new caledonia , south pacific, i'm the new owner of a JJ1400........will fired it up in a few.... i've a AMD hawk waiting for him, but, as it is my first turbine, i think it's certainly more "safe" to first fly it on a trainer have you an idea of a trainer? or do you think the hawk will be ok? i fly planes for 23 years now, and helis for 10 years...but turbine is completely new for me the other problem; is that we have problems with large parcels on my island, it's first very expensive for shipping, and sometimes purely impossible so, is there any "plan" of a trainer for the JJ1400 ? all advices are welcome! thanks a lot! kind regards vincent from new caledonia.......... sorry for my bad englishi'm just a poor frenchie lost in south pacific |
RE: JetJoe OWNERS thread
This has all been covered before in the mags+RCU maybe like teaching granny to suck eggs, just thought I'd mention I still see jet jockeys breathing fumes and looking up the exhaust with terminal possibilities. Paul |
RE: JetJoe OWNERS thread
Ok, I have some numbers to report with the two different exhaust cones. Thrust was tested with the engine in the plane so there will be some loss due to tire friction etc. Outside air temp was about 55 degrees
Two piece tail cone produced 9 lb 0 oz at 160k and 635 EGT Single piece cone produced 10 lb 6 oz at 160k and 650 EGT Todd, you stated: "Remove 1.5mm from the lenght of the outer cone.... This opens the diameter of the cone up a tad and, from what I am told, make a world of difference on the output for this engine!?" Is this when using the shorter two piece or longer single piece cone? I may give this a shot but seems the single piece is the one I want to keep using. Thanks, Mike |
RE: JetJoe OWNERS thread
ORIGINAL: YLF Ok, I have some numbers to report with the two different exhaust cones. Thrust was tested with the engine in the plane so there will be some loss due to tire friction etc. Outside air temp was about 55 degrees Two piece tail cone produced 9 lb 0 oz at 160k and 635 EGT Single piece cone produced 10 lb 6 oz at 160k and 650 EGT Todd, you stated: "Remove 1.5mm from the lenght of the outer cone.... This opens the diameter of the cone up a tad and, from what I am told, make a world of difference on the output for this engine!?" Is this when using the shorter two piece or longer single piece cone? I may give this a shot but seems the single piece is the one I want to keep using. Thanks, Mike Dave |
RE: JetJoe OWNERS thread
1 Attachment(s)
Well my curiosity got the better of me and I opened up the engine to see what may be causing the problem and I'm guessing this is it:
I have put just over 5 hours on this engine Which Joe sent to me back in September S/N 752. I can honestly say that I have never seen temps higher than 700 and then only for a few seconds during a start up or two. Mike |
RE: JetJoe OWNERS thread
What plane is the engine in? Is there a pipe or is it open. A truer test would be without a pipe and the best test would be off the plane and on a bench. However for a comparison of tail cones it is fair.
With the Wren engines they suggested on the early ones to narrow the exhaust to produce more thrust but warned of a rise in temps. Seeing that your engine has higher temps with the single piece suggests that it is more restrictive than the two piece cone. If you could match the temps you may be able to match the thrust. If that didn't work you could then try Todd's method to open it up. Of course onece you cut or remove the material there's no going back. Just saw your post above. What are you using for fuel, ACID?[X(] |
RE: JetJoe OWNERS thread
Count yourself lucky that none of those corroded vaporizer tubes broke off and caused your turbine wheel to destruct on the way out. An example of fine metallurgy that. Scott
|
RE: JetJoe OWNERS thread
Typical of what I have seen with this combustion chamber.... Ever wonder why reliable, quality engines use inconnel? ;)
This issue was pointed out very early on but certain individuals said we where full of poo...:eek: bygones.... Anyway, the one piece tailcone is the one you want to shorten by 1.5mm for thrust increase. At least for a few hours...[:-] |
RE: JetJoe OWNERS thread
ORIGINAL: YLF Well my curiosity got the better of me and I opened up the engine to see what may be causing the problem and I'm guessing this is it: Mike You have indentified the heart of your problems, no need for more guess work as your combustion chamber is in need of a replacement or a major repair job. I would have expected to see this type of condition only after say repeated multiple wet starts and with temps *****g out over 800c on running. I'd wonder if they are inconel if you are usually under 700c. A PM to Andy at Anglesey Turbines might give a few suggestions as he will give you an unbiased opinion, as you are not in the UK. He does offer a different CC which I have used on three of mine. The figures on the exhausts was a very useful comparison since it was on 'like for like' basis (ignoring the CC condition). The usual temps I have recorded are 620c on tick over 45k falling to 565c on max rpm, so I'd expect you to be able to drop 70-80 degrees at max rpm. With other adaptations on one JJ1400 I was able to get 560c at 45k falling to 480c at 160k, much much cooler but thrust was down requiring further work and more restriction to the exhaust. Cooler temps also allowed higher rpms above 160k. Look forward to hearing how you resolve these immediate problems. Paul |
RE: JetJoe OWNERS thread
ORIGINAL: rcdriver22 Mike You have indentified the heart of your problems, no need for more guess work as your combustion chamber is in need of a replacement or a major repair job. I would have expected to see this type of condition only after say repeated multiple wet starts and with temps *****g out over 800c on running. I'd wonder if they are inconel if you are usually under 700c. A PM to Andy at Anglesey Turbines might give a few suggestions as he will give you an unbiased opinion, as you are not in the UK. He does offer a different CC which I have used on three of mine. Paul I agree I should get one of Andy's CC's since this is probably why he makes his own. I'm sure Joe will send me a replacement but if it's the same material as this one why bother. My first 1400 had about 2 hours of run time on it and the CC had not started to deteriorate at all so I wonder if they had some that were made with inconel tubes and some that weren't? Todd, Once I get the CC replaced I will get another reading then shorten the one piece cone 1.5mm for comparison. Mike |
RE: JetJoe OWNERS thread
Before you start cutting, make sure you and Todd are talking about the same tailcone. I have an early single-piece tailcone that has a MUCH smaller opening than my later one piece tailcone, and I don't know if Todd has seen the later one, or if that's what you have. Obviously, there is a problem that is NOT involving the tailcone!
|
RE: JetJoe OWNERS thread
ORIGINAL: EASYTIGER Before you start cutting, make sure you and Todd are talking about the same tailcone. I have an early single-piece tailcone that has a MUCH smaller opening than my later one piece tailcone, and I don't know if Todd has seen the later one, or if that's what you have. Obviously, there is a problem that is NOT involving the tailcone! Todd, any chance of me getting a measurement from your friend who opened theirs up? Mike |
RE: JetJoe OWNERS thread
ORIGINAL: YLF My first 1400 had about 2 hours of run time on it and the CC had not started to deteriorate at all so I wonder if they had some that were made with inconel tubes and some that weren't? This was an early problem on JJ engines which some point in production #600+ the CC were implied to be changed fully to inconel, makes you wonder how or why an old CC got into yours. JJ owners with say 10+ hrs running time are not reporting your particular CC problem. JJ needs to replace yours with a full inconel CC. Paul |
RE: JetJoe OWNERS thread
ORIGINAL: lov2flyrc Anyway, the one piece tailcone is the one you want to shorten by 1.5mm for thrust increase. At least for a few hours...[:-] mm i just wondered why i even replyed here .......... help?[:-] |
RE: JetJoe OWNERS thread
ORIGINAL: Sandor ORIGINAL: lov2flyrc Anyway, the one piece tailcone is the one you want to shorten by 1.5mm for thrust increase. At least for a few hours...[:-] help?[:-] [quote] lov2flyrc Date 4/1/2006 1:53:59 AM Anyway, the one piece tailcone is the one you want to shorten by 1.5mm for thrust increase. At least for a few hours... |
RE: JetJoe OWNERS thread
ORIGINAL: YLF ORIGINAL: EASYTIGER Before you start cutting, make sure you and Todd are talking about the same tailcone. I have an early single-piece tailcone that has a MUCH smaller opening than my later one piece tailcone, and I don't know if Todd has seen the later one, or if that's what you have. Obviously, there is a problem that is NOT involving the tailcone! Todd, any chance of me getting a measurement from your friend who opened theirs up? Mike Also...have you THOUGHT of just sending the engine back to Jetjoe in China? Really, that's the best bet, and shipping is cheap. He has been very good about support for me. |
RE: JetJoe OWNERS thread
ORIGINAL: EASYTIGER Also...have you THOUGHT of just sending the engine back to Jetjoe in China? Really, that's the best bet, and shipping is cheap. He has been very good about support for me. ET is spot on suggesting now going for some factory support, as for all the many words here on RCU about Jetjoe he is good at answering emails and I've always found him very easy to deal with good technical support. I'd think it worthwhile just sending back the CC for his inspection, saves on your postage and then US customs thinking you have a new turbine, coming back into the country. If Joe agrees, which is likely, he can cover your costs with some useful spares. Paul |
RE: JetJoe OWNERS thread
As far as I understood... The tailcone that should be shortened is the latest single piece, I will inquire with my contact to confirm.
Todd |
RE: JetJoe OWNERS thread
Thanks, Todd. Like I said, I THOUGHT you might be talking about the older one, I would love to have confirmation.
RCdriver, agreed on all respects. |
| All times are GMT -8. The time now is 05:04 AM. |
Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.