Chuks
Senior Member
Joined: August 2015
Posts: 498
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Post by Chuks on Aug 19, 2017 18:59:35 GMT -5
hi every one,
its been a long time i haven't posted here, a lot has really been happening with my turbine life.
i got the oil pumps fixed which gave me what i what I wanted except for the fact that it goes off when the pressure gets somewhere around 5 bars and comes
one after some seconds until the oil temperature gets high from the preheating, then of cause the pressure goes down to say 3 bars,
thats when the pump gets stable.
am so scared of it going off when the engine is on.
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Chuks
Senior Member
Joined: August 2015
Posts: 498
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Post by Chuks on Aug 19, 2017 19:16:26 GMT -5
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Chuks
Senior Member
Joined: August 2015
Posts: 498
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Post by Chuks on Aug 19, 2017 19:27:41 GMT -5
as you already know, I have only two pumps, am running one as scavenge pump while the other one with same capacity as the main supply pump,
so I had to bypass some.
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Chuks
Senior Member
Joined: August 2015
Posts: 498
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Post by Chuks on Aug 19, 2017 19:28:00 GMT -5
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Chuks
Senior Member
Joined: August 2015
Posts: 498
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Post by Chuks on Aug 19, 2017 19:29:26 GMT -5
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Chuks
Senior Member
Joined: August 2015
Posts: 498
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Post by Chuks on Aug 19, 2017 19:39:36 GMT -5
I also changed the fuel pump with lots of things to try. Inside my head, am thinking that having a copper pipe coiled few turns around my exhaust pipe will terminate the need of adding 10 percent of petrol in my diesel and also compensate my out numbered avaps tubes. what do you think? thanks for your understanding.. IMG-20170710-WA0023 by Chuks Anthony, on Flickr IMG-20170710-WA0021 by Chuks Anthony, on Flickr
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Chuks
Senior Member
Joined: August 2015
Posts: 498
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Post by Chuks on Aug 19, 2017 19:44:38 GMT -5
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Chuks
Senior Member
Joined: August 2015
Posts: 498
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Post by Chuks on Aug 19, 2017 20:10:00 GMT -5
sorry, the oil return holes got overheated by the oil and got busted, so the engine thought that was diesel and sucked it in and it eventually used it
as a fuel and tried pull things apart.
in case you didn't know,this is my first time of seeing a jet engine talk more of powering it.
thanks to you all I have more to learn.
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Post by racket on Aug 19, 2017 22:58:13 GMT -5
Hi Chuksy
LOL..........an enjoyable video :-) ..............plenty of information to be found from watching it .................heh heh , maybe tie it down a bit more securely for the next test run .
Congratulations on getting her running .
Cheers John
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Post by Johansson on Aug 20, 2017 0:49:44 GMT -5
Congratulations!!!
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CH3NO2
Senior Member
Joined: March 2017
Posts: 455
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Post by CH3NO2 on Aug 20, 2017 8:52:40 GMT -5
I also changed the fuel pump with lots of things to try. Inside my head, am thinking that having a copper pipe coiled few turns around my exhaust pipe will terminate the need of adding 10 percent of petrol in my diesel and also compensate my out numbered avaps tubes. what do you think? thanks for your understanding.. Hi Chucksy My guess is there wont be very much heat transferred into the fuel with the 4 coils air wrapped around the exhaust outlet tube.If you can hook up a thermocouple at the end of the coil wrap, you can measure the fuel temperature rise. If you were to braze or silver solder just 1 coil wrap onto the exhaust tube, the heat transfer will shoot up dramatically. But be careful, you dont want too much heat transfer. You will have to continuously measure the temperature and watch it closely. You want the fuel hot but not too hot. Then at shut down, you will have to watch the coil temperature even more closely. When the fuel flow stops at shut down there will be thermal soakback into the fuel remaining in the coil. All of the hot metal parts, with their thermal inertia, will soak their heat into the fuel remaining in the coil. The fuel will boil off and hopefully it wont crack, coke or decompose. The only way to know is to put thermocouples all over the place and watch closely. To prevent injector clogging, carbon deposition or gummy build up you must avoid fuel decomposition. Tony
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Post by Johansson on Aug 20, 2017 15:07:12 GMT -5
I think that the fuel coil is a bad idea, at shutdown all of the fuel trapped in the copper coil will start to boil and cause flames and soot inside the engine. Possibly even cause occasional syringe blockages just as Tony mentioned. You are doing great progress with your engine, when the oil leaks are fixed it will run like a pro! Cheers! /Anders
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Post by racket on Aug 20, 2017 16:59:53 GMT -5
Hi Chuksy
Yep, I'll go along with the removal of the fuel coil , too many uncertainties , better to just add 10-15% petrol to your diesel .
On the scavenge oil problem , your scavenge pump is too small , it needs to be several times the supply capacity to accommodate all of the air/gases that bypass the seals .
If you don't have that extra capacity you'll end up with pressure between the engine and scavenge pump rather than a "vacuum" , if you have pressure combined with hot oil ,any plumbing will need to be in either metal or very high pressure (hydraulic type) flexible tubing otherwise it will fail .
We only need a scavenge pump at shutdown of the engine , during normal running conditions, gravity, and any air/gas pressure will shift the used oil back to the tank if its situated below the engine.
You need a tee piece in your scavenge line between the engine and pump , on that tee line you need a very lightly loaded check valve that will allow oil/air/gases to pass when the engine is running but which will close/seal sufficiently at shutdown for the "smallish" scavenge pump to then do its job of sucking oil from the engine.
Cheers John
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Chuks
Senior Member
Joined: August 2015
Posts: 498
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Post by Chuks on Aug 22, 2017 13:19:59 GMT -5
Hi John, anders,Chn302
Thanks for your comments. The coil will have to live the engine for good, but before that let me clarify my intentions, if it's found not helping then of cause it should go.
Yes, I tought about unused fuel coursing troubles to the engine after shutdown, So the ideal is constantly leaving the few pump onn allowing it to suck in air by adding a solenoid valve before the pump. When open it should suck air (during preheating and after shutdown)but when closed it will start to suck fuel from the tank(during start/running) . Then the shutdown command should be opening the solenoid valve for air to come in an flush the rest of the fuel on the coil while the fuel pump remains on for some time, reasons is to allow the air from the pump to cool the injector and prevent it from blocking.
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Chuks
Senior Member
Joined: August 2015
Posts: 498
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Post by Chuks on Aug 22, 2017 13:22:30 GMT -5
Hi John,
Am trying to arrange on how to get it done your way. Not sure if our market can provide this kind of valve required.
Nice ideas.
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