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Post by racket on Jul 6, 2023 2:45:50 GMT -5
Hi Ralph The test run today didn't go well youtu.be/lPfva0e1sPg , I had a failed start due to there being a turbine rub , thankfully theres only minor damage to the edge of the inducer when a "scab" formed on the turb shroud, possible a piece of turbine/NGV material from an earlier FOD failure that had been embedded in the shroud and possible "shifted" during the last test run . I've pulled the engine and have removed the outer can , everything else looks OK at this stage , so I'll try and remachine the turb shroud , not going to be an easy job as the component has suffered some warpage from too much abuse over the last year :-( One thing I need to check is possible axial displacement of the shroud due to its mounting flange on the NGV wall possibly having dished forward bringing the shroud closer to the wheel . Thanks again for your support offer , others need it more than me :-) Cheers John
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Post by racket on Jul 7, 2023 1:39:19 GMT -5
Hi Guys
Bit of an update .
I found that the axial clearance between wheel and shroud was well below what I made it originally , so understandable that there was a rub , I've probably been lucky in my couple of previous spoolups .
I've had the shroud in the lathe attempting to add some clearance , but the thing is warped in all directions :-(
Guess I'll just grind out enough clearance at the narrowest point and accept a bit of excess clearance at other positions , thankfully with a wheel of this size an extra 10 thou of clearance isn't too much of a problem .
More work tomorrow , but I had a good look at the flametube and its still OK .
Hopefully back together over the weekend and another run next week :-)
Cheers John
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Post by racket on Jul 8, 2023 0:43:10 GMT -5
Hi Guys
Engine back together :-)
The "machining?? " took a bit longer than expected , there was considerably more material to be removed than I can understand .
I can now pass a 0.025"dia wire gauge along the blade between it and the shroud , so good to go :-)
Back on the test stand tomorrow and onto the trailer ready for a test run
Cheers John
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Post by finiteparts on Jul 8, 2023 17:24:07 GMT -5
Bummer to hear that it rubbed, but glad to see you were able to clean it up and get it ready to go again.
Good luck on the next run! Chris
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Post by racket on Jul 8, 2023 18:38:47 GMT -5
Hi Chris
Thankfully it was at lowish speeds so not much damage done , but the change in clearances has me perplexed , I'm pretty fussy about my clearances and can't understand how the shroud could have moved forwards by the 0.025"needed for contact , I had to remove a lot of shroud material to restore the correct clearance , theres no large asymmetrical air loads with my slipjoint on the exhaust stub .
LOL.......maybe I'd better check the turbine shaft lengths next time I have it apart , in case this replacement wheel isn't quite up to spec :-)
I've also removed the IGV stator whilst I had the engine apart, hopefully the widened surge slot will control things better than previously before adding the IGV , I might need to run a "high idle " to move the operating conditions to more favorable areas as even with the IGV the low speed running was a bit "unstable " with plenty of compressor noises .
Cheers John
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Post by racket on Jul 9, 2023 20:51:38 GMT -5
Hi Guys
Test run this morning , all went well , no dramas , a nice smooth 12 second spoolup :-)
I removed the IGV stator for this test with some "interesting?? " changes to the manometer readings , far too much air going out the surge slot , might need to re install the stator with a bit less deflection angle , maybe only ~10 degrees so that theres a tad of surge slot exhaust at full power rather than the blast I have at present or the vacuum of previous tests
Cheers John
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Post by racket on Jul 16, 2023 21:04:29 GMT -5
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Post by enginewhisperer on Jul 16, 2023 23:27:11 GMT -5
that's quite a lot of power!
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Post by racket on Jul 17, 2023 0:20:06 GMT -5
Yep :-)
I was a tad worried about my camera/s
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ripp
Veteran Member
I'm sorry, I don't speak english, so I torment you (and myself) with a translation program,Sorry
Joined: January 2013
Posts: 236
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Post by ripp on Jul 17, 2023 3:19:07 GMT -5
Impressive! congratulation! John, would it be possible for you to set the camera to at least 720p? Cheers Ralph
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Post by racket on Jul 17, 2023 4:00:42 GMT -5
Hi Ralph
What is "720p " ??
The camera I'm using for the gauges is an old Canon IXUS 105
I was relatively happy with todays run , but I feel the A/B might need a bit more fuel ,
Cheers John
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Post by pitciblackscotland on Jul 17, 2023 7:35:42 GMT -5
Looks like you had a very good run there John Look like That camera shock around from the shock waves from that afterburner Cheers, Mark.
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WilliamTQ
Member
Joined: March 2015
Posts: 38
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Post by WilliamTQ on Jul 17, 2023 12:40:01 GMT -5
Congratulations on an excellent run and results
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Post by andym on Jul 17, 2023 13:58:04 GMT -5
Hi John
Nice run.... looking forward to chatting to you about it
But wonderful :-)
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Post by racket on Jul 17, 2023 16:55:46 GMT -5
Thanks guys :-)
LOL.........its interesting how a "click bait" title suddenly increases the number of views , I've already got more views than any of my other vids , heh heh , I might even break the 1,000 mark
Cheers John
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