APS/Ω Gas turbine bike build

[Mobacken Racing]

WHAT???, no hockey this season?.

Seriously, Anders I wish you all the best.

No hockey whatever season.

Thanks!

[charlie101]

Tack för uppdateringarna! Det är så skoj att kunna följa bygget och imponerande på alla sätt.

[Mobacken Racing]

Det var så lite så, kul att nån ids följa ett sånt här långtidsprojekt.

[Old Scrambler]

Now your talking my language...not...but its still OK........but not as cool as your hobby

[Mobacken Racing]

I did another run today up to 3 bar boost pressure, still problems with falling oil pressure but I think it is the tank foam (oil proof fuel cell foam) that is restricting the oil circulation. I have removed the foam and will do another test run ASAP to confirm the theory.



Cheers!
/Anders

[Speed Limit 1000]

What power level do you expect?

John

[Mobacken Racing]

What power level do you expect?

John

>250hp and a shitload of torque.

[Old Scrambler]

That could get you a Red Hat on the salt

[Mobacken Racing]

That could get you a Red Hat on the salt

That would be nice.

I did a quick birthday run just now to see if the removal of the tank foam has cured the oil pressure problem, but unfortunately it didn´t since the pressure started to drop toward 4 bar as you can see. I backed off the throttle and stopped the engine at that point.



I think I am onto something though. After the run I did some thinking when the oil pressure still was low, and noticed that the regulator bleed line was still flowing oil. I tightened down the regulator screw as far as possible but there was still a considerable flow through the bleed line back to the tank. The darn spring must be too weak!

I searched through my shelves and found a stronger spring that fitted the regulator after a little work on the belt sander, with the new spring installed the bleed flow stopped and the oil pressure rose to 5.5bar which can be considered the maximum pressure with that oil temp.

An annoyance at the moment is the preheat, it tends to flame out when I start to spin the rotor up and that empties the small air tanks pretty fast. I will figure something out the next time I disassemble the engine.

Cheers!
/Anders

[Mobacken Racing]

Tonight I rearranged the preheat system a bit, it has bothered me that the preheat tends to flame out when I start spinning up the rotor and the crappy placement of the propane feed is to blame.



So, to solve this without having to add an internal propane manifold I came up with an idea to replace one of the 18 fuel injectors with a propane dito, this will feed propane into the evaporator tube which puts the preheat flame right where I want it in the primary zone.



The old propane injector was replaced with a spark plug long enough to reach the combustor.



This proved to be a very good arrangement where the propane lights off almost instantly and the flame is kept high up in the combustor instead of burning down past the turbine like before.



I also added a 3D printed knob to the oil regulator setting screw so I can more easily adjust it by hand.



Before I called it a night I made a new jetpipe pressure pitot tube, this one sits closer to the turbine wheel which should give me a more accurate reading. I just need to get a 6mm hydraulic fitting to couple it to the pressure gauge.



Cheers!
/Anders

[Mobacken Racing]

The oil pressure is still giving me grief so I have decided to build a better pump since that is the only thing left untouched during the oil pressure R&D, I have a Procon vane pump that I will couple to a 250w 12v motor that I have ordered. That is almost twice the power of the oil pump I use now so it should be more than powerful enough to give me a solid oil pressure.



While waiting for the pump motor to arrive I have started building a new guide vane stage for the power turbine, the old one was home built but now I am using an original Rolls Royce C20 NGV stage for better efficiencies and power.



Cheers!
/Anders