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Post by pitciblackscotland on Sept 28, 2011 3:58:13 GMT -5
Don't forget the fire extinguisher just in case. Good luck.
Cheers, Mark. :-)
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Post by racket on Sept 28, 2011 4:26:52 GMT -5
Hi Anders
With the scavange pumps , can you wire it so that the scavange pumps have to be operating before the pressure pump is armed so as to prevent pumping oil into the engine where it can't "escape" except thru the seals , .......................I was always forgetting to switch on the gearbox scavange pump on my first bike build .
As for a combustor drain , maybe a 3mm hole drilled thru the casing at a point where you'll eventually fit the drain , it'll indicate is fuel is pooling whilst not leaking too much P2 air .
All the best for Sunday, I'll be thinking of you :-)
Cheers John
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Post by Johansson on Sept 28, 2011 14:36:18 GMT -5
Not easily, but I have made a checklist for the starting that includes seeing scavanged oil in both transparent return lines before I open up the starting air bottle so I think I´ll be fine. I checked the engine just now and luckily for me the spark plug is mounted almost 6 o´clock on the engine casing, so I can just remove the sparkplug to drain the engine. The threaded boss protrudes a bit into the engine but not far enough for any larger amounts of oil/diesel to pool up inside. Thanks John, I think you know exactly what kind of thoughts that goes through my head right now only days away from the maiden start.
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Post by racket on Sept 28, 2011 17:14:49 GMT -5
Hi Anders
Checklists should be mandatory .......................LOL, even with one I still "forget" things in the heat of the moment ...................this old brain gets befuddled with all the "excitement??" :-(
Heh heh , yeah , got a fair idea what you've going through right now ......................and probably a few you don't need to know about ;-)
I've got confidence in you , it'll be a success , just keep Olov checking those TOTs .
Cheers John
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Post by Johansson on Sept 30, 2011 15:08:51 GMT -5
I bought a carbon dioxide fire extinguisher today i case I need one for the test, much better than the shitty powder extinguishers that spreads its content over the entire workshop.
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Post by propellanttech on Sept 30, 2011 15:46:34 GMT -5
I bought a carbon dioxide fire extinguisher today i case I need one for the test, much better than the shitty powder extinguishers that spreads its content over the entire workshop. I would have went with a Halon, but they are expensive and sometimes hard to find. CO2 will work.......probably just as well. James
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wolfdragon
Senior Member
Joined: April 2011
Posts: 287
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Post by wolfdragon on Sept 30, 2011 16:41:35 GMT -5
CO2 or halon is a must when dealing with any engine, the powder will just melt and give you one hell of a bad day when you are tearing down everything to get that crap out of wherever it got
watched a guy hit his valved pulse jet with a powder extinguisher and spend the next three hours swearing and picking/scraping...
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Post by propellanttech on Sept 30, 2011 16:57:08 GMT -5
CO2 or halon is a must when dealing with any engine, the powder will just melt and give you one hell of a bad day when you are tearing down everything to get that crap out of wherever it got watched a guy hit his valved pulse jet with a powder extinguisher and spend the next three hours swearing and picking/scraping... CO2 can cause a bad day as well, if the cold CO2 hit's any hot parts. I have seen bad things happen with CO2. That is why I recommend Halon. It's not cryogenic, although it can suffocate you if in enclosed quarters. EDIT: Ok CO2 is not actually cryogenic. But it does go through a thermal expansion process to produce a very cold vapor, which will shatter parts if they are hot enough. END EDIT. James
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Post by Johansson on Sept 30, 2011 23:56:15 GMT -5
Halon would be best as you say, but finding one here in over-protective Sweden is the tricky part. Older machines for forest harvesting often have halon extinguishers so I will ask a friend who drives one if he have one he can take with him tomorrow. When I was in my early 20s I visited a scrap yard to search for suitable combustor shells and found two mid sized halon extinguishers that I got practically for free, since I found them in a pile of scrap I assumed that they were empty so I just threw them in the back of my trunk and drove off to work. I remember that they had those pull cords with which you could release the gas witout having to pull a safety pin, those cords had come lose and were just dangling free while the two halon extinguishers were rolling around in the trunk with all the other stuff I had there for aprox. 200km before I got back home. Imagine my surprise when I realized that I had been driving around with two filled Halon bottles tumbling around in the trunk, I wouldn´t even have had time to stop the car before I had been stone dead if one had blown its content...
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Post by propellanttech on Oct 1, 2011 3:03:56 GMT -5
Halon would be best as you say, but finding one here in over-protective Sweden is the tricky part. Older machines for forest harvesting often have halon extinguishers so I will ask a friend who drives one if he have one he can take with him tomorrow. When I was in my early 20s I visited a scrap yard to search for suitable combustor shells and found two mid sized halon extinguishers that I got practically for free, since I found them in a pile of scrap I assumed that they were empty so I just threw them in the back of my trunk and drove off to work. I remember that they had those pull cords with which you could release the gas witout having to pull a safety pin, those cords had come lose and were just dangling free while the two halon extinguishers were rolling around in the trunk with all the other stuff I had there for aprox. 200km before I got back home. Imagine my surprise when I realized that I had been driving around with two filled Halon bottles tumbling around in the trunk, I wouldn´t even have had time to stop the car before I had been stone dead if one had blown its content... Actually, it probably wouldn't have killed you. Halon is heavier than typical air, so the lower part of your car would have been filled with halon. I was in a building once which had it's halon system go off. It wasn't a pleasant experience, but not really life threatening. We didn't stick around in there long though. James
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Deleted
Joined: January 1970
Posts: 0
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Post by Deleted on Oct 2, 2011 4:53:02 GMT -5
hope all goes well today
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Post by Johansson on Oct 2, 2011 12:48:38 GMT -5
The test was a success! I had some problems getting used to the very sensitive throttle control and balance it with the starting air so I ran out of air in the bottle before I could get it started during the first attempt. A new bottle was fitted and I gave it another go, this time I opened up the air a bit faster and off it went! The P2 was kept around 0.3-0.4bar which might have been the reason why the TOT started to climb from 600°C to 700°C where I decided to abort the run, a teardown after the engine had cooled down showed no visible damage to the engine other than some deposits on a couple of syringe injectors and that the coating on the SS2368 NGV vanes had started to come off. The heat patten on the combustor indicates that the combustion might be a bit to far downstream to be optimal, how does this compare to your 10/98 combustor John? It also leaked a bit of oil during the startup, this might be pooled up oil in the bottom of the casing that is blown out past the O-ring seal around the compressor housing once there is positive pressure inside the engine. Before I run it again I will fit a drain valve to the casing so I can let any residual oil or fuel out just by opening up the valve. I am happy with the test, the engine survived and that is all that matters at this point. Now I can figure out the possible improvements and plan for another test session this winter. Thanks for your interest guys, I appreciate it!
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Post by turbochris on Oct 2, 2011 15:47:34 GMT -5
wooo hoooo!!! she's a runner! I guess just keep running it and looking inside. it seems like it wants to run!
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Post by racket on Oct 2, 2011 17:03:59 GMT -5
Hi Anders
Congratulations :-)............ thats the worst of it over and done with , much easier next time .
Very sensitive throttle ........................Heh heh , those large flames reminded me of my first spoolup attempts with the TV84
Yep, bit of oil seepage is "normal" for first attempts , the alloy housing should quickly expand into the stainless can and the O'ring will seal better , I had oil leaking from the GT6041 scroll after first spoolup, it had bypassed the seal during "testing??" of the oilpump, I've also had it on the TV84 turb scroll , probably from running high oil pressures without the rotor turning .
Flametube "colour" is OK , the flametube is working "hardest" at low power settings , lotsa airflow, relatively high temperatures but low air pressures meaning the combustion intensity is higher than at high power settings , if it'll run at low power settings it should be just fine at higher ones , ........................I did notice that the "purpleing" extended further forward behind the diffuser exit air deflectors , you may need to "adjust" the distribution by having partial deflection over more of the diffuser exits .
The high TOT temps might be partially caused by the lowish P2 , it might improve once up to ~1 bar , if it doesn't you might need to improve the inlet air flow to the engine , theres a fair number of tubes and fan struts that could be causing turbulence at the inducer reducing efficiency. .....................I sorta remember something about NGV throat areas as well , were they a little on the large side ??
Lots to digest , you'll be spending a few days "debriefing" and checking video for clues
Otherwise , a successful first spoolup , you can be very proud of your creation :-)
Loved the suit and tie for the occassion ;-)
Cheers John
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Post by pitciblackscotland on Oct 2, 2011 17:33:26 GMT -5
Congratulations Anders, All that hard work and hours of machining has paid off. Time to celebrate!!!. Cheers, Mark..
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