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Post by racket on Apr 2, 2017 22:25:46 GMT -5
Hi Andrew
Don't know about the sensor , but the gauge is good for 99,999 rpm .
Might have to do a bit of research on them , they can be used with up to 36 volts, the 24 volt test didn't make much difference to the 12 v so I don't think extra voltage will help :-(
The flick test gives good results so it could be a sensor problem at higher rpm especially as the comp blades are alloy and kinda thin , so maybe not giving a good enough signal .
Cheers
John
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Post by enginewhisperer on Apr 2, 2017 23:02:33 GMT -5
yeah they seem a little bit too good to be true if they work on turbos - compared to the price of the usual turbo speed sensors.
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Post by racket on Apr 2, 2017 23:15:17 GMT -5
Hi Andrew Think I've found it , specs on the LJ8A3-2-Z/BX www.ekt2.com/pdf/14_PROXIMITY_INDUCTIVE__8BX.pdf , please check my maths on this ...... only 0.5 Kz frequency , now as I'm reading 8 blades , the unit reaches its max at only a few thousand rpm of the comp :-( .......my starter would have the comp at that in milliseconds. Need something with ~10 KHz response frequency range , 8 blades at 1,000 revs/sec = 8,000 responses/sec ..................gotta keep looking :-) Cheers John |
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Post by racket on Apr 2, 2017 23:39:14 GMT -5
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alan
Member
Joined: August 2010
Posts: 36
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Post by alan on Apr 3, 2017 0:02:49 GMT -5
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Post by enginewhisperer on Apr 3, 2017 0:41:51 GMT -5
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CH3NO2
Senior Member
Joined: March 2017
Posts: 455 
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Post by CH3NO2 on Apr 11, 2017 7:40:13 GMT -5
52 pages of the most intelligent and creative thread I've ever read. Where's the "Like" button?
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Post by racket on May 7, 2017 23:12:50 GMT -5
Hi Guys
Bit of an update on this mornings test run .
It was a cool 14 deg C at 7.30 am , oil was a tad thick so it took 3 tries before I finally got her to spoolup .
Unfortunately nothing much has changed , its OK up to a 2:1 PR , but then it starts to burn unreasonable amounts of fuel with temps spiking :-(
Comp efficiency was ~77% at a 1.5:1 PR , dropping to ~75% at 2 and 2.5 :1 PR ., this is lower than my last test , but that tests reading were possibly corrupted by the "ambient" thermocouple being "heated" by air getting discharged through the surge slot , I moved the thermocouples position further from the engine for this test.
I'll pull the engine and completely disassemble it so that I can measure everything and hopefully come up with some ideas .
The video taken showed nothing new , so haven't uploaded anything ...........will post a few pics when I get her disassembled
Cheers
John
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Post by Johansson on May 8, 2017 0:36:43 GMT -5
Bugger.  |
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Post by racket on May 8, 2017 0:44:12 GMT -5
Hi Anders
Yep :-(
Cheers
John
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Post by jetjeff on May 8, 2017 0:49:24 GMT -5
Hi John,
Sorry to hear that. Building a turbine with an internal combustion chamber is the hardest endeavor I've ever attempted. Definitely not for the faint hearted.
My build has taken a bit of a backseat to all the work I have to do around my house, now that spring is here.
Regards
Jeff
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Post by racket on May 8, 2017 3:17:50 GMT -5
Hi Jeff
LOL...........we're both in the same boat , now that autumn is here in Oz and the temps have cooled down its time for me to start work on the house, I'm hopeful of renovating the kitchen/dining area this year , I wanted to get one last test run in with the engine before getting the paint brushes out .
Theres a lot of things that can go wrong with our "micro" type engines , especially when the comp/turb aren't a good match , hopefully I'll have a better idea what to look for inside the engine now that I've done a fair few test runs .............I'm still not sure if its fuel, combustion, flametube length or lack off , or maybe I've simply "pushed the envelope" a tad too far ............its a shame because it sounds so good at a 2:1 PR
Cheers
John
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Deleted
Joined: January 1970
Posts: 0
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Post by Deleted on May 8, 2017 4:00:57 GMT -5
Hi John
:-(
Am sure if any ones going to work it out, you will
All the best
Andy
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Post by racket on May 8, 2017 19:51:11 GMT -5
Hi Guys
I've been in contact with the fellows over on the GTBA Site with regards to my ongoing problems, and the Technical Officer Nick Howarth has reviewed things and generously spent considerable time doing a spread sheet for me, which will take a few days to slowly digest all the data at various "off design " points .
Cheers
John
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Post by Johansson on May 9, 2017 16:48:46 GMT -5
That is great of him, always good to have an expert check in on things when you are stuck. I would know since I must have emailed you a thousand times about my engine problems...  |
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