duncan
Junior Member
Joined: December 2014
Posts: 68
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Post by duncan on Jan 1, 2015 14:51:42 GMT -5
Hello everyone & greetings from Indy! I joined JATO just about a week ago after finding it via Google, while searching for info regarding the Fairchild J44 turbojet engine. I bought one (a J44-R-24 from 1954) in November of 2013 & just got it running almost exactly a year later, this November. I am doing this as a hobby & possible 'retirement project', and because boys never really grow up, only their toys do! I enjoy electronics & mechanical stuff, so jet engines go right down my line.
I started on JATO reading a thread called "New member here with a J44...", which was started by member 'dond', where I posted a few comments. I decided to join JATO & start a new thread to cover this engine project. I do not have any still camera shots of the first start attempts nor the first & second runs; I do have video & plan to upload them to You Tube once I buy a new computer & edit them. I hope to help others in the gas turbine engine world as well as learn from you as well! Speaking of You Tube, check out "Back Yard Jet", parts 1 & 2, as well as the over 300 videos on jet engines from 'Agent Jay-Z', a jet tech in Canada! He has spent a lot of time sharing his experiences with us, including lots of test cell time, as well as theory & practices. Recommended here!
Cheers!
Darren Duncan
Here are a few photos of the beginning, including fabrication of the wonderful 'run stand' built by Mark of BoMar Industries: image upload
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duncan
Junior Member
Joined: December 2014
Posts: 68
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Post by duncan on Jan 1, 2015 14:55:40 GMT -5
SUMMARY <So Far>:
Since I have no prior experience with gas turbine engines & the J44 in particular, this project has been one of reading, trial & error, failures & successes! I have a nice copy of the USAF manual covering the J44-R-3, and I also have one of those old orange tech school manuals I got from Essco Aircraft (On Ebay), which covers the J44-R-24, which is my model. According to the manuals, the R-3 uses a more sophisticated fuel control system while the R-24 uses a simpler design. My R-24 is 'in between' that shown in the 'orange' manual & the R-3. My engine has an 'Acceleration Limiter Valve Assembly' in line between the governor fuel control outlet & the fuel cutoff valve. The R-3 also has a limiter valve, along with the servo control fuel system. Its purpose is to limit overtemping & compressor stall due to too much fuel at once. It measures compressor inlet, outlet, & fuel pressures then adjusts the maximum fuel flow to safe limits.
Overall, my main concern was the fuel control system & its operation. The previous owner said, "It runs." & I did find the filter container & lines to be clean, with no gunk or worse yet, corrosion! I wasn't sure if it would even start & then if it wouldn't just speed up out of control. Well, it starts & accelerates right up to idle at about 31-32% RPM so that part seems OK.
The next concern was that the lube system is/is not working. I ensured that the lines were clear & even pressurized the system with compressed air (less than 30 PSI!), which produced the 'oil mist'. After that test, I had excess oil running out of both bearings. I checked the front frame & inside of the jet pipe, at the rear bearing support, for oil puddling/running, after each run. This indicates the system is working & supplying oil! Looks good here.
Starting her was the next challenge. I tried with straight K-1 but got no light-off; just fuel spraying & blowing out of the exhaust. After 2 tries like this, I contacted the previous owner, who has had several of these engines. He said "These J44s are hard to start & generally won't, using just K-1 or even Jet A. You need to add some gasoline to the mix! About 20-30%. That should do it." Well, I mixed about 2.5 gallons of gas into my 8 gallons of K-1 already in the fuel cell, then purged the fuel system up to the fuel manifold. That did the trick! It lit-off with a 'Poof'! I killed it a couple of seconds later due to the fact that I didn't have any help with spotting & fire extinguisher manning. A second start try fired right off also, so I felt it was ready for a test run.
With a couple of friends to assist me, we rolled it out into my driveway on another day & made the first full start & run! It quickly came up to idle, with my hand nervously on that Emergency stop button, then stabilized at about 31% RPM. What a rush! You can 'feel' that power there, albeit a small & old school engine with a 1.65 lb./hr./lb. thrust. Yes it does drink some fuel! About 0.75 gallons per minute at idle! My 15 gallon fuel cell should run about 20 minutes at that setting & only about 7-8 minutes at full power! The used fuel boost pump I bought on eBay will not flow enough to run the engine above 50% RPM, which is fine for a start. I will replace the pump (28 V, mounted on the stand down next to the fuel cell) when other bugs are worked out & I can afford it. I get 25 PSI with the fuel cutoff valve closed & it drops to about 15-20 at idle. Accelerating to 40% causes a drop to less that 10 pounds, so not much left.
On the first run, upon observing the tail pipe view of the engine, I have discovered some erosion of the turbine nozzle blades around the '8 to 10 o'clock position', where I could see fire visible through it. Upon closer examination using a flashlight on a cool engine, I can see the some deterioration of several of the nozzle (stator) blades. This will require removal of the rear end & turbine wheel, to access the nozzle assembly. I am hoping my buddy can weld it up because these aren't around anymore! I don't think it is safe to run it up over idle with this damage; actually it really should not be ran at all! There is a chance that a blade could break-off & damage the turbine rotor! This would be a good time to have the turbine inspected for cracks or other signs of stress, as well as replace the rear bearing if needed. I will try to get this done before Spring, God willing.
In conclusion, I have taken almost a year since buying the engine in November of 2013, to get it running. That was a great feeling of accomplishment to reach that point! Half of the 'fun' is just the engineering, building, wiring, plumbing, troubleshooting, changing & getting it to run! Running it & sharing that experience with friends is the other half. I could have just patched it together some simple switches & wires but I wanted to make a cleaner look, so I just spent more money & bought some nice hardware! I have to buy a new computer so I can edit & process my videos! This old system (from 2006, Windows XP) just chokes on these HD video files! I will upload them to You Tube as soon as I can. I hope my experience can benefit some of you out there in gas turbine engine/J44 world! Also, I hope to learn more about them from you as well. Take Care & Cheers!
Darren Duncan
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duncan
Junior Member
Joined: December 2014
Posts: 68
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Post by duncan on Jan 9, 2015 18:42:05 GMT -5
Hey all, I have added a few pix to the 'J44 Project' album. They are of the new fuel drain line, from the fuel cutoff valve to the fuel cell & the removal of the 45 degree fitting that was on the boost pump inlet. The drain line allows excess fuel left in the manifold, line & cutoff valve to drain back to the tank when the engine is stopped. When the valve is de-energized, a spring slams the valve to the "OFF" position, which cuts the high pressure side off & also connects the outlet port (feeds to the fuel manifold & nozzles) to the drain port, allowing most of the fuel to immediately drain out. Without this drain, the fuel drains into the combustion chamber, keeping a fire going after the engine stops! Also, some excess fuel already in the chamber makes a hotter, 'fireyer' start, which ain't good either. If any fire is still burning inside the engine or tail pipe after a shut-down, the engine must be motored via the starter until it is out.
The change in the fuel line from the tank to the pump inlet was just a matter of rethinking the installation. Why did I ever put that 45 on the pump inlet in the first place? Thought it was necessary at the time but I never liked it. I removed the fuel cell to install the new VDO fuel level transducer/sending unit, to work with my VDO fuel gauge on the console. It will give me some idea of how is in the tank & about how many seconds I have left! It is a 0 - 90 Ohm resistance unit with a simple float & it fits a wide range of tank depths. Upon reinstalling the tank onto the stand, I was able to remove the 45 fitting & just run it straight off of the pump. Looks much better.
A couple of other changes are: Connecting the hour <time> meter to the "Fuel Valve" switch, so that it only runs (keeps time) when the fuel cutoff valve is "OPEN", as in when it is running & installing a large ('Max') fuse holder & 60 Amp fuse inside of the stand electrical box, to protect the charging circuit & connector (jack) on the side of the box. It is connected directly to the batteries, at the starter relay & common (-) ground terminals. A short at the connector or in the charger cord could result in a fire & damage, so installing a fuse will protect the wiring. The hour meter originally was connected so that it was on whenever system power was on... not a very good approximation of running time! Whenever the fuel valve is open (energized), the engine is running (or should be!), for the most part; this will help keep track of time on the engine.
DD
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alan
Member
Joined: August 2010
Posts: 36
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Post by alan on Jan 11, 2015 14:15:02 GMT -5
That is an interesting project you got going on there! What line of work do you do for a living?
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duncan
Junior Member
Joined: December 2014
Posts: 68
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Post by duncan on Jan 16, 2015 22:21:02 GMT -5
I am an electrician but have always had mechanical & electronic interests too. I have read alot of non-fiction books! Borderline nerd.
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duncan
Junior Member
Joined: December 2014
Posts: 68
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Post by duncan on Mar 4, 2015 0:55:18 GMT -5
Hey all & thanks for your interest! I finally have a few videos of this engine running on You Tube! My channel is simply "Darren Duncan", so just type in "Fairchild J44" into You Tube search & you will see them listed or try the links at the end of this post. I think there are 4; the first is a little intro & my first start attempt & first 2 light-offs! The 2nd, 3rd & 4th are of the engine actually running, however not much above idle! There is some deterioration of the turbine nozzle (stator) so I will be removing the hot section this Spring to see what I can do... no new nozzle available any more for this antique!
DD
Here are the links to my first videos:
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duncan
Junior Member
Joined: December 2014
Posts: 68
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Post by duncan on Nov 8, 2015 2:15:17 GMT -5
Hello all out in turbine land. I have uploaded a couple of new videos regarding the J-44 Project. One is an overview of the 'system', including the engine, accessories, peripherals, the stand & control console. The other deals with the turbine nozzle damage that has been growing and is now to the point of red-tagging the engine until it can be fixed. This will be a Winter project, which I plan to video parts of, to share later. I know these parts aren't available so I am hoping for a repair via a the same guy the fabricated the stand. It may not be possible but something needs to be done, else the engine will destroy itself or become a nice sculpture! I have ran the engine about 6 times this year, since the uploading of "Runs 3 & 4", noticing increasing erosion in the same area (3 airfoils), while the rest of the nozzle looks OK. My be due to a hot streak from the annular combustor, in that location, which I will look into after removing the nozzle. See all of my J-44 videos on You Tube! Thanks for checking in and stay tuned...
Here are the links to my (2) NEWEST J-44 videos:
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dond
New Member
Joined: February 2014
Posts: 8
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Post by dond on Jan 16, 2017 22:25:17 GMT -5
Awesome project you've got going there duncan! I'm not too far along with mine, but, alas I don't think I'll be able to finish it. I was diagnosed with cancer 2 years ago and am now on hospice at Stage 4. I'll probably offer it for sale soon on this board( if allowable) or ebay or something the like. Thanks for letting me join you guys- been some fun reading! -Don D. Leeds, Alabama
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duncan
Junior Member
Joined: December 2014
Posts: 68
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Post by duncan on Jan 18, 2017 19:35:33 GMT -5
Don,
Well, sorry to hear such news; it re-enforces the 'Life is short!' theory! I lost my sister-in-law a couple of years ago due to the 'c' word! 15 months from diagnosis to her passing at the age of about 65. Hopefully, you will make a liar out of the medical experts & complete your project. I have not been on JATO for a good while, as I have been chasing parts & money for my J44. I need to update this blog with some photos & some explanations. Basically, I have found a good, used turbine wheel & nozzle, had them and some other parts glass bead blasted, & plan to start reassembly of the engine next month, hopefully get it back together by Summer. I have videos on You Tube of the disassembly & of the replacement parts, if anyone is interested. Search for "The J44 Project" or "Darren Duncan". Stay in touch, Don, & prayers for you.
Darren
01.18.2017
PS: I remember your engine & I just reviewed your older (2014-2015) posts. That is a very early version of the J44, with the little 'reverse' cone on the exhaust end. All of the non-flight-rated versions use a one piece turbine wheel <rotor>. My metal guy looked at mine & says that those blades a WELDED to the disc! Not by hand, of course, but by an electrical 'fusion' process. If you look close, you can see the different look to the 2 metals where they join! The blades are of a higher temp alloy than the FORGED <not cast> disc. I find it hard to believe that the blades are welded but you cannot hardly cast such a hunk of metal & spin it up to 16K RPM! As far as I know, the flight-rated engines were only produced the last few years (1958-1960?), & the -3 is the main version. The -3 has replaceable, individual turbine blades with a fir tree root.
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duncan
Junior Member
Joined: December 2014
Posts: 68
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Post by duncan on Mar 12, 2017 19:44:52 GMT -5
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scuferrari
Member
Up to 5 Jet Engines and 2 Gas Turbines and Looking for more.
Joined: September 2010
Posts: 24
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Post by scuferrari on Mar 26, 2017 14:25:23 GMT -5
Hello Duncan, I purchasing my second J44 not to long ago,it a very nice and complete engine, and after a good cleaning it does not look to have every been started i can still see white paint markings on the turbine wheel if it was ran not very much and the oil tank looks to never had oil in it? My only problem is the older J44 used 2000psi air to start it and has a AC generator where the starter is bolted on the newer ones, do you or anyone here have any idea where a J44 starter could be found? watching your videos i see the starter mount is the same as the generator on mine. one more thing anyone know if a 3 phase 115v AC generator can be converted to a starter/generator. Thanks
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duncan
Junior Member
Joined: December 2014
Posts: 68
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Post by duncan on Dec 26, 2017 12:56:05 GMT -5
It's PAST TIME for an update of "The Fairchild J44 Project"!!
Not yet done but progressing with the reassembly of the J44, after much reconditioning & replacement of everything! Of course, much of this is posted in boring video form on You Tube; just go look for 'Darren Duncan' or 'The Fairchild J44 Project' & you will see a list of my productions. I apologize for the delay in posting/updating here on J.A.T.O. but it's been a crazy 2017! I am including some pix to show the progress, including the cleaned-up, used parts from a 'doner' J44. As you know, my original turbine stator (nozzle) & turbine wheel had been overheated, badly, so they had to be replaced. The parts engine was in good shape, with apparently little run time on it, by looking at its condition inside. Therefore, I used the combustion chamber, turbine rotor & stator (nozzle) from it, having them glass bead-blasted to clean them up. I was able to find brand new bearings for this engine so those were installed as it was reassembled, along with some hand made gaskets, as well as a new compressor shaft seal. I painted the insides of the castings with a 'Glyptal' type paint, which is used to coat the inside of engine blocks (oil proof) & electric motor windings (high temp), to help keep corrosion down. There was some oxidation here & there from years of sitting around, probably outside, so I wanted to preserve it well as I could. Not the original green coating inside of the diffuser & front flange but better than nothing! The intake housing was bead-blasted then powder-coated the olive drab green color (again, not the same as the original but I wanted the aluminum protected, plus it looks good!), along with the combustion chamber mounting pins, give the engine some 'accent'! The cowling was sanded with a power sander (a D.A.), to give it a nice luster. The exhaust nozzle housing was also bead-blasted then just hillbilly painted with Rustoleum BBQ Grill paint! It's gonna burn-off anyway, so looks good for now!! The rotor assembly, which consists of my original compressor & shaft, mated with the replacement turbine wheel, was balanced by a very understanding & cool jet shop owner, who liked my project & took the time to mess with my it. Thank you Jay. The engine is back together overall, with no accessories installed on the outside of it, but it is once again sitting horizontally on its stand/fixture! I have checked clearances between various rotating parts & their neighboring stationary parts, changing the compressor spacer (shim) thickness to obtain specs. The next step will be to install & torque the compressor shaft spanner nut, then close-up the front bearing housing with the shaft seal & O-ring installed in the bearing retainer, then torquing the retainer nuts. A buddy is fabricating a spanner nut 'holding device', which is used to hold it while the shaft is turned to tighten it, as directed in the service manual. This was a special tool supplied by Fairchild back in the day, but like most old things long forgotten, you have to make your own tools sometimes. I am hoping to get her running again by Spring of 2018! There is still a bit of work to do, as I am making a few changes as I go, if possible, to correct or improve operation & function. The E.G.T. indicator system is one I will pay close attention to, as keeping an eye on turbine temps is the most important & critical parameter! I am experimenting with a couple of new thermocouples & bought a digital thermometer to compare them with. Thanks for your interest & I will try to update this post soon!
Some pix:
upload picphoto uploader
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duncan
Junior Member
Joined: December 2014
Posts: 68
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Post by duncan on Oct 28, 2019 10:35:10 GMT -5
October, 2019
Greetings all, hope to find everyone well. And now, the big announcement long overdue, the J44 is alive & running once again! After a 3+ (4?) year restoration, it is back together, looking good & running! I had found a 'parts engine' (a J44-R-20), with apparently few hours on it, to donate the hot parts I needed for my J44-R-24. I used the turbine rotor, turbine stator & the combustor from the parts engine, with pretty much everything else the original parts to restore this little turbojet. Thanks to Agent JayZ of Jet City Turbines for the balancing of the rotating assembly & thanks to Mark of BoMar Industries for the fabrication of miscellaneous 'special tools' & parts.
I have posted 2 'newer' videos on my You Tube channel, "Darren Duncan", of the first runs since restoration. There is more work to do yet, including a few modifications to the electrical system & a larger fuel boost pump on the stand that can deliver the proper amount of fuel to run much above 50% RPM.
Thanks to all that have followed this project & I will hopefully have more to post in the future, as I progress.
Cheers,
Darren Duncan
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jasonr
Member
Joined: October 2019
Posts: 28
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Post by jasonr on Oct 31, 2019 4:40:11 GMT -5
Darren, congrats on your restore. I have watched most of your videos on your j44, so cool to see how far you have come with your engine. I am new here but thought this was a good place to start, as I am going to look at a j44 this friday. A couple questions I have is where have you found parts engines, and what kind of inspection would you reccomend before buying. I'm not sure of the condition the one I'm looking at is in or what model it is, looks like maybe an r20, I'm also not sure to pay for it thanks for any help. Jason. btw here is a picture.
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