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Post by smithy1 on Jan 2, 2017 20:01:02 GMT -5
Hi Smithy Still looking OK , really getting into the interesting bits now :-) Cheers John Yeah...she's looking pretty healthy, although I did find a tiny crack, ~0.100" on the turb wheel at the inducer hub web between two blades, I spoke to our engineer and he thinks it'll be fine, it's in the "meaty" part of the hub....We've seen worse cracks in C20B turbine wheels and their cracks can go to ~0.300" ...not much more to it really... I'm going to acid dip the bearing housing and other cast iron bits...then I'll give them a grit blast and paint with high temp paint...should come up ok. With the comp housing, I will just mask up the inlet bell, then give it a light blast to remove any existing crud...then a light paint with aluminium coloured high temp paint and hopefully she'll look pretty good.....how long the paint will last on the turb scroll is anyone's guess. The paint is "ceramic based" and supposedly good for >1000C..I suspect it won't last too long though. Time will tell...I'll take a few shots when it's going back together. Cheers, Smithy. |
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Post by racket on Jan 3, 2017 3:46:06 GMT -5
Hi Smithy
Yep , a classic spot for a crack , thermal related , one of the reasons for the scalloping out of the backwall between blades .
If you do a good clean job on the scroll the paint should last a while , I generally find its my laziness that ruins my paint jobs .
Could you please give me a measurement of the shaft axial length between the comp wheel and turb wheel bosses , the 20 odd mm dia section so that I can compare length to a TV94 shaft as I'm curious to know just how much extra length it would provide in a "micro" engine .
Cheers
John
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Post by smithy1 on Jan 3, 2017 15:02:36 GMT -5
Hi Smithy, Could you please give me a measurement of the shaft axial length between the comp wheel and turb wheel bosses , the 20 odd mm dia section so that I can compare length to a TV94 shaft as I'm curious to know just how much extra length it would provide in a "micro" engine . Cheers John Ah...I'm sorry John, I've already refitted the rotor assembly yesterday...Doh..!  Cheers, Smithy. |
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Post by racket on Jan 3, 2017 15:15:35 GMT -5
LOL.............you're working too fast, at this rate you'll have it back together and burning kero by the weekend :-)
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Post by smithy1 on Jan 3, 2017 16:09:26 GMT -5
LOL.............you're working too fast, at this rate you'll have it back together and burning kero by the weekend :-) That's the plan...LOL... I have a car show at Warriewood on the northern beaches on 29th of Jan and need to get her back together and hopefully a test run before hand, should give me enough time to repair any issues which may arise...can't rock up to an event and have it not run properly now can we?  I'm planning to do a minor mod to the starting system, I still want to try and eliminate the need for propane to start...I've done a few experimental starts and she fires up sometimes without the propane but it's a bit intermittent/hit 'n miss...I think the primary fuel spray at low rpm and next to no P2 is possibly a bit heavy, so I'm thinking of using a "start injector" next to the main C20B injector, I have a few P&W PT6 nozzle tips laying around and they have a real nice "fine" mist type spray which will hopefully help. I can "T" a -4 line from the main feed and fit a small flow divider valve which I can use to switch from one injector to the other, essentially a "primary to secondary" system. Cheers, Smithy. |
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Post by smithy1 on Jan 4, 2017 14:25:59 GMT -5
A couple more progress pics:  Just for size comparison..! ;-)   Cheers, Smithy. |
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Post by stoffe64 on Jan 4, 2017 15:53:00 GMT -5
Looking good Smithy, fantastic fast buildup of the engine, happy new year to you also, Cheers /stephan
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Post by racket on Jan 4, 2017 16:24:37 GMT -5
Hi Smithy
She's looking very nice after the paint job :-)
It'd be handy if you can do away with the LPG cylinder , looking forward to seeing what you come up with.
Cheers
John
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Post by pitciblackscotland on Jan 4, 2017 19:59:05 GMT -5
G'day Brett, Looks good  Did you rebalance the rotating assembly  Cheers, Mark. |
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Post by smithy1 on Jan 5, 2017 18:45:28 GMT -5
Looking good Smithy, fantastic fast buildup of the engine, happy new year to you also, Cheers /stephan Thanks Stephan....there's not much to them really...only a handful of parts...most of the time involved was cleaning and preparing for painting etc.. Cheers, Smithy. |
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Post by smithy1 on Jan 5, 2017 18:47:56 GMT -5
Hi Smithy She's looking very nice after the paint job :-) It'd be handy if you can do away with the LPG cylinder , looking forward to seeing what you come up with. Cheers John Will be interesting to see how long the so called "high temp ceramic paint" lasts on the really hot bits. I'll still have the LPG start system available in the engine, (just in case)...but yeah...it would be nice not to have to need it..! Cheers, Smithy. |
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Post by smithy1 on Jan 5, 2017 18:58:47 GMT -5
G'day Brett, Looks good Did you rebalance the rotating assembly Cheers, Mark. Hi Mark, Yeah, I gave it a quick spin on our Schenck balance machine at work....I've had no vibration issues before dis-assembly so I suspected it was ok, the bronze bearings and thrust bearing showed no evidence of any imbalance...at 1500rpm it was ~55-60mg-in at each end, which is very good for a hydrostatic bearing setup...but I did take a "little" metal off each end, not much though as I had punched in a 20mg-in tolerance...which is nothing for a rotor this big, Rolls-Royce C20B engines use 28mg-in as the maximum tolerance for their compressor rotor assembly....works fine for them..! Cheers, Smithy. |
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Deleted
Joined: January 1970
Posts: 0
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Post by Deleted on Jan 8, 2017 13:51:09 GMT -5
Hi Smithy
Found this video
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Post by smithy1 on Jan 8, 2017 18:00:01 GMT -5
Hi Smithy Found this video Hi Andy, Yeah..that was early December at the V8 Supercars 3 day event here in Sydney....had a wee flame-out that run too, was me being a bit quick letting the throttle back to idle...no dramas as I have the blower handy and the igniter is running all the time...! ;-) Cheers, Smithy. |
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Post by racket on Jan 30, 2017 2:23:42 GMT -5
Hi Smithy
Could you please provide me with some numbers for the bleed slot in your comp housing ,..............where is it placed axially between the main and half blade , and axial width of the slot .
I'm considering doing something on the 12/118 and have been researching map width enhancement just in case my 12/118 problems are being caused by surge with a comp of unknown "map" shape.
Cheers
John
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Did you rebalance the rotating assembly 
