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Post by Johansson on Jun 12, 2017 15:48:21 GMT -5
I cleaned up the turbine cover today. While I had the engine apart I welded two stainless M10 nuts to the engine cover so I could make a puller for it, now it is very easy to remove the cover. I assembled the engine again so now I am just waiting for a pressure gauge fitting to arrive before I can do another test start, some of the front cover screws aren´t aligning perfectly with their threaded holes so for the initial low P2 runs I´ve decided to run without them and fix the aligning the next time I have the engine apart. Cheers! /Anders
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Post by Johansson on Jun 11, 2017 14:36:17 GMT -5
A very sweet starting engine! Thumbs up!
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Post by Johansson on Jun 8, 2017 16:58:18 GMT -5
Thanks Skynet! When I first started the JU-01 is smoked like crazy since there was oil leaking everywhere and the casing was not sealing properly.
I was very satisfied with yesterdays starting attempt when there was literally no smoking at all except from the jet pipe when the preheating flamed out.
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Post by Johansson on Jun 8, 2017 0:54:57 GMT -5
Thanks! The leaf blower seems perfectly capable of spooling her up, so that is a huge relief. It is perfect for the initial testing since scuba air start only gives you a couple of seconds to get the fuel into the engine before the air pressure starts to fall.
I decided to remove the test stand PWM controller for the bike fuel pump and use the bike twist grip PWM instead, this gives me the added security of fuel pump shutoff in case the oil pressure gets below 3kg.
Cheers! /Anders
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Post by Johansson on Jun 7, 2017 16:25:48 GMT -5
I just got back in from pulling the engine cover off to find out what caused the rub, the kero smoke had cleared a bit while I was drinking tea and uploading the video. The turbine wheel inducer has rubbed at one spot as you can see. In the turbine cover there are two slightly protruding spots that has cased the rub, it looks like this is some burr from the combustor that has come lose and got stuck between the blades and the cover. If it would have been a tight tolerance the rub shouldn´t have occured in two small spots like that, I´ll grind the spots away and measure the cold clearance again. Before I assemble the engine again I need to come up with a way of removing the engine cover easily, the silicone O-ring makes it difficult to do by hand so I need to make some kind of tool for it. I´ll also add a spark plug boss. Cheers! /Anders
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Post by Johansson on Jun 7, 2017 14:28:15 GMT -5
I couldn´t wait for the P2 gauge to arrive so I kicked open the shed doors and gave her a spin this evening! As you can hear either the compressor or the turbine wheel started to rub its casing due to the heat expansion of the internal engine parts. I will disassemble the engine and locate the rubbing area and increase the clearances at that spot a bit. All part of the usual R&D, nothing to worry about. Cheers! /Anders
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Post by Johansson on Jun 7, 2017 0:49:44 GMT -5
I did a quick test with the 2.5kg propane regulator and it spins up really nicely with full oil pressure and the leaf blower! No signs of rubbing despite a prolonged preheat cycle which got the engine warm and cosy. As soon as I get the P2 gauge and fittings I´ve ordered I think the JU-02 is ready to take its first stumbling steps. One thing that didn´t work as planned was the glow plug igniter, I can´t get it to light off the propane no matter what propane flow I am testing so I think that I will fit a spark plug boss to the engine cover the next time I take it apart. Until then I will simply light the propane through the jetpipe with a torch. Cheers! /Anders Hi Anders... Love your work as usual, really looking forward to your first JU-02 "light-off". With the glow igniter, what voltage are you sending through it?? I have a 12v diesel engine glow plug in the 6041 engine...I found mine glowed fine and looked good outside the combustion chamber, but once inside with a goodly amount of cold air going past it during start it may be falling a bit short. Mine was/is very hit 'n miss at 12v, sometimes it lights straight away, sometimes never. I'm suspecting it doesn't work too well at 12v...maybe one or two more volts may help?? I haven't tried this myself yet though. I know they can handle over 14v without too much trouble. I'm wanting to use mine for kerosene start rather than propane...although I always have propane available if needed. Cheers, Smithy. You might very well be correct in that, earlier when I tried it in open air with a newly charged battery it lit the propane instantly. It looks like the plug glows a bit duller now so the bike battery might need to be charged. I´ll need to remove it since I cannot rely on a fully charged battery for the preheat to work, but it is an easy fix since I can keep the preheat plug as the propane injection point and just add a spark plug. I ran the leaf blower at full flow through the engine without blowing out the preheat flame so that is fine. Hi Anders You might be having a fuel/air ratio problem at the glow plug , does it light without any air from a spinning comp wheel ?? Cheers John Nope, no ignition even with the preheater removed from the engine and tested in the open air. HAHA! Creative shot! Got the pic not even seconds after taking the torch off of it.
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Post by Johansson on Jun 6, 2017 14:28:28 GMT -5
I did a quick test with the 2.5kg propane regulator and it spins up really nicely with full oil pressure and the leaf blower! No signs of rubbing despite a prolonged preheat cycle which got the engine warm and cosy. As soon as I get the P2 gauge and fittings I´ve ordered I think the JU-02 is ready to take its first stumbling steps. One thing that didn´t work as planned was the glow plug igniter, I can´t get it to light off the propane no matter what propane flow I am testing so I think that I will fit a spark plug boss to the engine cover the next time I take it apart. Until then I will simply light the propane through the jetpipe with a torch. Cheers! /Anders
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Post by Johansson on Jun 6, 2017 11:49:01 GMT -5
Now it is just the boring job of wiring the JU-02 test stand up left to do... I welded together two AN6 fittings to connect the JU-02 oil line to the bike. It ended up like this: I connected the preheat module and adjusted it so the glow plug gets to heat up for 10 seconds before the propane solenoid opens. I also connected the load cell, it reacts when the engine is pushed forwards but I need to do some head scratching to figure out the badly translated manual in order to calibrate it against a known force. Cheers! /Anders
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Post by Johansson on Jun 3, 2017 15:11:02 GMT -5
Great work Chris!!! A really unique looking engine, congratulations on getting it running! I see one big error with it though, it seems to lack a power turbine at the rear end. Cheers! /Anders
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Post by Johansson on May 31, 2017 15:41:40 GMT -5
I have been curious about the condition of the gearbox since it has been run hard for two years now, if the gear loads are excessive it would show by now so I decided to take an oil sample from the gearbox sump where all of the crap would pool up. Since I am responsible for, among other things, the hydraulic systems at work I have all the equipment needed to run a test. With 25ml of oil sampled through 0.8micron paper I could check it with a microscope to see what sort of stuff that got caught. I was expecting all sorts of crap since I run the oil system without a proper oil filter, but I was pleasantly surprised to find very little metal particles. This indicates that the wear on the gear mesh is acceptable. The sample paper looks much worse to the naked eye than it does in the microscope, the dullness and occational black dot is most likely from the new tank foam I filled the oil and fuel tanks with. Nothing even close to being large enough to clog up an oil port so it is all ok. I have taken samples from gearboxes with worn cogs and the papers look like they are chromed from all the metal particles on it... Cheers! /Anders
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Post by Johansson on May 31, 2017 15:25:57 GMT -5
Last night I continued building the test stand for JU-02, a crude dashboard for the preheat system was made out of aluminum sheet. The idea is to have a switch wired both to a relay which operates the glow plug and to a timer that opens a propane gas solenoid valve once the plug has had time to heat up properly. Not very fancy but functional, it is no use overdoing the test stand since I will make a new housing for the preheat when I am installing it in the bike. I also welded a nut to the jet pipe in which the temperature probe will sit, the idea is to use the bikes oil system and fuel pump but have separate P2 and TOT gauges on the test stand and a separate test stand mounted PWM controller (you can see it below the load cell gauge in the previous pic) for the fuel pump so I won´t have to mess with the bike PWM settings. Cheers! /Anders
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Post by Johansson on May 28, 2017 23:03:16 GMT -5
Hi Ty! (figured your name out from the youtube channel ) Welcome to the forum! That sounds like a very fun senior project, a sweet running engine so far and you seem to be set on improving it in the future as well. The fact that you are planning to add a regenerator to it gave me goose bumps, I´ve never seen one made for a DIY engine before so it would be a great contribution to the community if you decide to do it and later share your experience with it here at JATO. Cheers! /Anders
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Post by Johansson on May 28, 2017 0:19:11 GMT -5
Hi Anders Looking good Nice touch having the comp blades aligned on their "axis'" ..............heh heh , are you getting a tad anxious to see her spin ?? ;-) Cheers John Hi John, Ha, I didn´t notice that. A bit yes, but it is still a while before I have everything hooked up and ready to go. I have my doubts about the leaf blower being capable of getting it spinning fast enough, but I guess we´ll find out. Cheers! /Anders
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Post by Johansson on May 27, 2017 10:59:27 GMT -5
Fitted some stuff to the test rig today, I must have gotten mayonnaise on the camera lens since the pic was so blurry... Cheers! /Anders
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