Johansson´s Pocketbike

[Mike Everman]

Beautiful work, Anders! You turbojet guys put us valveless guys to shame in terms of effort.

[Johansson]

Thanks!

I designed the flame tube the standard way by giving it the same hole area as the comressor inlet and dividing the tube into three zones, the primary got 30% of the inlet area, secondary got 20% and dillution got 50%.

The "problem" was to estimate how much air that would flow through the hooked vapour tubes, John (racketmotornman) said that a hooked tube would flow roughly 50% of what a hole of the same diameter flows, but if they are flowing more like 70% the primary zone are getting too much air and could blow away the flame.

//Anders

[Nick]

That is soooo cool mate, absolutely love it!!!! bet you cant wait to ride it!!!!

Nick

[Johansson]

Yep, it will be very exciting to take her out for the first spin around the village! =)

Today I have fitted small guidance vanes on the inside of the flame tube where the primary holes are. They will make the air entering there flow around the tube wall instead of blowing straight at the flame as it did before. I have also made two stainless thrust nozzles for the exhaust, they turned out really nice as you can see on the pics I will post later this evening...

I am also mounting an air solenoid for the impingement starter so it will be eaiser to start the bike next time.

//Anders

[racketmotorman]

Hi Anders
Yeh , those large primary holes might be the culprit .
Theres a pic of my kart engines flametube on Nicks site
http://www.nickhaddock.co.uk/turbine_st ... 030526.JPG
Which shows how I positioned a couple of 6mm?? holes opposite each evaporator outlet (they're at top of pic) and further down the flametube there are more 6mm? between the 4 evaporator outlets that are made to point back upwards into the space between the evaporators to promote recirculation .
Your large primary holes will act more like main dilution holes , so your modification should at least get some swirl going to slow down the axial velocity , but you might still need some "recirculation" .
Looking forward to more test results :-))
Cheers
John

[Johansson]

Aha, those holes were for recirculation? I will soon find out if I need some of those.

Here are the pics I was talking about.

//Anders

[Anders Troberg]

I hope that oil tank is a temporary solution. You have made such beautiful work, it would not be right to have its beauty marred by that.

Why not buy one of those aluminium flasks that you can buy for 20 kr in just about every store nowadays (I've seen them at Rätt Pris, ICA, Hemköp, Dollar Store and some petrol stations)? You can even get them in an anodized jet engine red color!

[Johansson]

The bottle needs to be transparent so I can see how much oil there is left, so a fancy aluminum bottle is out of the question. I have managed to hide it quite well behind the cover below the right handlebar so it won´t ruin the looks of the bike.

After 8 straight hours in the garage the bike is as good as finished, all that is left is the fuel tank which I am going to make tomorrow and a mc-battery. All wiring is done, a push-button start is made with an air solenoid and the fuel system is rearranged so the throttle wire can be fitted easier. Before the weekend is over I will do a second testrun to find out how the combustor modifications came out, so stay tuned!

//Anders

[Nick]

looking forward to more film of the start up and Run !!!

Nick

[Fricke]

Ahh now it´s an "Jag aer en festis" bike =)

Check Your e-mail...

Nice work by the way!

Strap it on the big bike and take it with You on the road-trip later this summer... Here is a barrel of JET A1 to burn!!

[El-Kablooey]

Dude, that's just awesome beyond description. I can't wait to see a vid of you riding that thing!

[Johansson]

Yes, it is a total-loss system where the oil/air mix enters before the front bearing and goes out through the turbine where the shaft seal used to be. It will cause a little bit of smoke from the exhaust but it ain´t worth the extra effort to make it a closed system.

//Anders

[Johansson]

Today I have started working on the fuel tank, it is half done by now but I will spend a couple of hours more on it tonight and try to finish it.

While designing the tank I realised that it would not be possible to make a 4 liter tank without messing with the slim look of the bike´s tail, but I tried to make the lines follow the bike as close as I could. We´ll see tomorrow how it turns out...

//Anders

[Johansson]

Enough work for today. All that is left to do is to make a flange for the lid and a couple of fuel connections for the front baffle, then I can weld it and measure how much fuel it can take...

//Anders

[tufty]

I expect you've thought of this, but the suspension _does_ bottom out before wheel/tank collision, yes?

Beautiful work, by the way.

Simon