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Post by Johansson on Oct 22, 2015 15:45:58 GMT -5
Thanks for the reminder Ernie, those places have lots of useful stuff!
Mitch: In theory it should give close to 1.5 L/min but I haven´t had time to measure it yet, the idea is to use a Hobbs pressure switch to activate the pump at 2bar P2 and adjust the flow with a regular automotive fuel pressure regulator. I will hook P2 air to the regulator so the water pressure rises with the P2 to get some kind of linearity to it.
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Post by Johansson on Oct 24, 2015 12:58:23 GMT -5
I ran the bike this afternoon to test the bearing modification, the rotor spins up much easier now and the engine runs smoother somehow. Earlier it had a grumph to it like it was struggling to keep the revs up but now it just whistles along at 700°C exhaust temp which is 100°C colder than before.
I still haven´t checked the thermocouple for faulty temp readings so it might run even colder than that, I could feel a significant drop in rear wheel torque at idle when I applied the rear brake which isn´t very strange since the exhaust temps were much higher before.
Cheers! /Anders
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Post by racket on Oct 24, 2015 15:53:54 GMT -5
Hi Anders
Sweet spoolup :-)
Did you notice any difference in temperatures between when the rear wheel was spinning and when you had it stopped ??
The diffusing exhaust additions will be helping at all power settings , but 100 - 150 C degrees is a big change and represents a lot of energy thats not being "wasted" .
Was the P2 higher for the same idle throttle setting as previously ??
That back wheel was making a nice whistle , it was spinning pretty fast :-)
Cheers John
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Post by Johansson on Oct 25, 2015 3:23:35 GMT -5
Hi John, There is a strange thing happening when I brake the rear wheel at idle, the P2 needle drops to 0 instantly. The revs drops a bit but the engine is still running so I haven´t figured out yet why the gauge reacts like it does. The idle P2 was a bit higher than before, so the thrust washer must indeed have been braking the rotor. As soon as Olov find some spare time we will get the tachometer sorted, then the bike is just about ready for next years One Mile race. Time to get busy on JU-02 then! Cheers! /Anders
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Deleted
Joined: January 1970
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Post by Deleted on Oct 25, 2015 5:36:52 GMT -5
Hi Anders
Does sound on video, that it spins up easier..... very odd on P2 needle drops like that. but hay we fix one thing, another issue comes a long :-) love it
All best Andy
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Post by Johansson on Oct 25, 2015 13:07:53 GMT -5
Hi Andy, Very strange indeed, I looked at the raw GoPro movie again and the P2 drops for a second or two when I brake the rear wheel before it restores itself to normal values. I think I will buy a snowmobile brake grip that has a locking lever, then I can lock the rear brake and start the bike without having the rear wheel in the air. Thanks, your bike is running very sweet as well! I am looking forward to some video footage of it screaming down the track at full throttle! Cheers! /Anders
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Deleted
Joined: January 1970
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Post by Deleted on Oct 25, 2015 16:13:58 GMT -5
Hi Andy, Very strange indeed, I looked at the raw GoPro movie again and the P2 drops for a second or two when I brake the rear wheel before it restores itself to normal values. I think I will buy a snowmobile brake grip that has a locking lever, then I can lock the rear brake and start the bike without having the rear wheel in the air. Thanks, your bike is running very sweet as well! I am looking forward to some video footage of it screaming down the track at full throttle! Cheers! /Anders Hi Anders well on 31st we at Santa pod, so weather permitting i will do what i can :-) take my time on first run, then let it have some revs :-) sure you soon work out the P2 issue, i just can not think why or what it could be All Best Andy
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Post by racket on Oct 25, 2015 22:58:53 GMT -5
Hi Anders
LOL.............zero P2 , thats an interesting one , ..............what sort of gauge/pickup do you have , is it electric or manual ??
I'd have expected the P2 to maybe rise a tad as the rear wheel/freepower stopped spinning , the extra backpressure possibly reducing flow back into a more efficient region closer to the surge line.
The main thing is , everything is sounding sweet :-)
Yep , you'll need to get those thermocouples sorted out for the JU-02 , you might need to get onto a reputable industrial instrument retailer and explain the scenario of having high temperature , high speed gases that you need to measure most accurately in the 500 to 1,000 C range , and see what they can recommend , for maximum horsepower we need to have absolute confidence that the temperature reading is within a couple of degrees of actual gas total temperature, it'll money well spent to have that "insurance".
Cheers John
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Post by Johansson on Oct 26, 2015 1:30:59 GMT -5
Hi Anders well on 31st we at Santa pod, so weather permitting i will do what i can :-) take my time on first run, then let it have some revs :-) sure you soon work out the P2 issue, i just can not think why or what it could be All Best Andy I am keeping my fingers crossed for the race! Hi Anders LOL.............zero P2 , thats an interesting one , ..............what sort of gauge/pickup do you have , is it electric or manual ?? I'd have expected the P2 to maybe rise a tad as the rear wheel/freepower stopped spinning , the extra backpressure possibly reducing flow back into a more efficient region closer to the surge line. The main thing is , everything is sounding sweet :-) Yep , you'll need to get those thermocouples sorted out for the JU-02 , you might need to get onto a reputable industrial instrument retailer and explain the scenario of having high temperature , high speed gases that you need to measure most accurately in the 500 to 1,000 C range , and see what they can recommend , for maximum horsepower we need to have absolute confidence that the temperature reading is within a couple of degrees of actual gas total temperature, it'll money well spent to have that "insurance". Cheers John It is a glycerine filled manual gauge so it cannot be some electrical hickup, very strange indeed but as you say it sounds ok so I don´t worry much about it. Could it be that I need to make some sort of radiant shield for the thermocouple so it can´t "see" the heat exiting the turbine NGV? A simple stainless pipe around it with a couple of holes drilled so the exhaust gasses can pass over it? Cheers! /Anders
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Post by racket on Oct 26, 2015 1:35:51 GMT -5
Hi Anders
Does the thermocouple have a sheath around it already and is slow to react , or is it a "bare wires" type thats fast reacting ??
Cheers John
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Post by Johansson on Oct 26, 2015 1:39:56 GMT -5
It is a slim sheathed Fluke probe, no bare wires.
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Post by Johansson on Oct 26, 2015 17:20:13 GMT -5
To help the air enter the engine I added a pair of radiuses to the air box entry tonight. Hopefully they will reduce some of the supposed turbulence when the air passes the sharp corners and into the air box. I also made a radiant heat shield for the thermocouple, you can see that slots are cut in the pipe so the exhaust can pass over the thermocouple for faster response. I´ve also figured out a way to lock the rear brake so I won´t have to start the bike with the rear wheel in the air, a small washer can be fitted behind the brake grip to lock it in place. I´ve just made cad drawings of it and will 3D print it tomorrow in nylon. Cheers! /Anders
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Post by racket on Oct 26, 2015 21:35:17 GMT -5
Hi Anders
Is the thermocouple a designed match for the gauge ??
Has the cabling between thermocouple and gauge been shortened ??
Is the cable shielded from other electrical interference ??
Like the "bellmouthing" of the inlet :-)
Cheers John
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Post by Johansson on Oct 27, 2015 1:22:45 GMT -5
Hi Anders Is the thermocouple a designed match for the gauge ?? Has the cabling between thermocouple and gauge been shortened ?? Is the cable shielded from other electrical interference ?? Like the "bellmouthing" of the inlet :-) Cheers John Hi John, 1. Nope 2. I have a Fluke cable extension that has been shortened to reach the digital gauge. 3. Not unless it is internally shielded somehow. 4. Thanks!
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Post by madpatty on Oct 27, 2015 9:20:42 GMT -5
Hi Anders,
Can you tell what type of fluke thermocouples you are using?
Cause i cant find any screw on type thermocouples from fluke that fit our purpose, they are mostly handheld type probes.
Can you paste a web link or something.
Thanks.
Cheers, Patty
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