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Post by Johansson on Oct 5, 2017 16:55:04 GMT -5
Hi Anders Just be careful that the suction line between engine and pump doesn't "collapse" under the "vacuum" created , especially once the lube starts to warm up , metal pipe or flexible hydraulic suction tubing. Cheers John Good pointer John, I´ll change the rubber hose I use now to a steel braided one. |
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Post by Johansson on Oct 5, 2017 16:26:44 GMT -5
Ahh, of course! That is something I never thought of, good to put the dry bearing concern to rest.  |
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Post by Johansson on Oct 5, 2017 12:00:37 GMT -5
I got the pump in the mail today, damn that was fast!  I think I need to PWM control it to balance the scavenge flow against the oil inlet flow, don´t want to suck the bearings dry from over capacity in the scavenge pump.  Cheers! /Anders |
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Post by Johansson on Oct 5, 2017 0:25:09 GMT -5
hi nersut the price is quite high In fact it is extremely cheap considering what a new inconel turbine wheel would cost. |
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Post by Johansson on Oct 4, 2017 23:02:16 GMT -5
It has a rubber impeller, the company told me that it should be ok as long as I don´t go past 80°C oil temp.
I haven´t so far gotten up to oil temps higher than that I can hold my hand against the oil tank without any discomfort so I think it will work fine, with the short run times and large oil capacity the oil don´t have time to heat up much.
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Post by Johansson on Oct 4, 2017 17:03:10 GMT -5
Today I´ve ordered the 60Ah LiFe battery and a new impeller-style oil scavenge pump, now I just have to keep myself busy until they arrive. Don´t think that will be a problem... |
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Post by Johansson on Oct 3, 2017 15:45:43 GMT -5
It is a good idea but I don´t think it is possible to do with a brass bearing engine, it would need ball bearings that can take the radial load from a auxiliary drive shaft for oil pumps etc.
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Post by Johansson on Oct 3, 2017 15:11:45 GMT -5
The parts are looking great! I am very glad to see the FM-1 coming to life again as a stronger and better engine (I fancy turboshaft engines as you might have noticed...) so I am following this with great interest! It is very easy to insert the pictures in the post, just click the "share" button in the upper left corner at the PostImage site and copy the direct link that ends with .jpg. When posting here you click the little button that looks like a painting and insert the link adress there. Voila!  |
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Post by Johansson on Oct 3, 2017 5:04:40 GMT -5
I´ve been discussing batteries with Andy over messenger, he runs LiPo and like them but I want to play safe with LiFe for just the reasons that you Smithy points out.
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Post by Johansson on Oct 2, 2017 12:23:28 GMT -5
Thanks dieselguy86 for the info, unfortunately we have had lots of trouble with LiPo cells breaking down on the jet kick because of cold/heat/vibrations/bad charging or some other cause so I have decided to keep away from them. I have so much on my mind during a race so the last thing I want to be concerned about is battery charging problems.
Slow charging is really not a problem for me, with 60Ah battery capacity I can run the bike a whole race day and charge the battery over night.
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Post by Johansson on Oct 2, 2017 4:42:55 GMT -5
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Post by Johansson on Oct 2, 2017 3:58:29 GMT -5
Anyone who has tried the 12V LiFe batteries? I want to buy a drop in 12V battery meant for vehicle use and not a pack of individual cells that needs to be soldered together or whatnot.
We measured the voltage drop over the battery cells so my thought is that the first step should be to change to a better suited battery and save the rewiring for later in case it is needed, lots of work to replace all the wiring so if a simple battery swap will get the pumps running happily again I can continue the engine tests soon.
Another though (many thoughts going through my poor head now...) is that perhaps a PWM controlled oil pump would be an idea, this way it won´t have to run harder than needed to produce the right oil pressure and keep the amperage draw down to reasonable levels. It feels a bit stupid to run the pump flat out and then have to regulate most of the oil back to the tank to keep the pressure where I want it.
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Post by Johansson on Oct 1, 2017 22:59:15 GMT -5
Hmm, perhaps I should consider LiPo batteries for my bike as well. The charging process scared me off when I built the bike but perhaps they have gotten more user friendly since then?
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Post by Johansson on Oct 1, 2017 17:09:58 GMT -5
Electricity is a pain in the arse, but I don´t think that a motor pump assembly is an option for the bike so I have to figure something out. Most likely I´ll make a stand alone wiring harness just for the test rig and rewire the bike later when the engine is sorted out. The cat was wondering what we were up to.  Cheers! /Anders |
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Post by Johansson on Oct 1, 2017 16:56:35 GMT -5
A tailpipe clip from the second run, it is one loud bugger even at only 1-1.5bar P2!
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