APS/Ω Gas turbine bike build

[wheelrdealer]

Thanks guys!

I spent my birthday at home with an ill daughter, nothing serious so we had a good time putting most of the outdoor summer stuff away and doing some rimfire plinking with my 10/22 in the back yard.

On the turbine bike department I am waiting for a load of stuff I´ve ordered to make a new and better throttle arrangement, until then I plan to get an AN fitting for a fuel pressure sensor made among some other stuff.

Cheers!
/Anders

I have been told by an ammo broker the 22 LR have the least profit margin of all of the calibers of ammo. So when there are limited raw materials, i.e. brass, powder or lead the ammo manufacturers shift production to the calibers with the higher profit margins. Therefore, 22s are the first to dry up. Seemed to make sense to me.

BR

Anders, around here 22 ammo has been hard to find and when you do the price is double what it used to be.

It makes no since to me because assault weapon ammo is easy to find.

The youth are the ones who are being deprived.

Wait a minute, maybe it does make since.  

  Don

[Mobacken Racing]

Anders, around here 22 ammo has been hard to find and when you do the price is double what it used to be.

It makes no since to me because assault weapon ammo is easy to find.

The youth are the ones who are being deprived.

Wait a minute, maybe it does make since.  

  Don

I´ve heard that a lot, that the US is almost depleted of 22LR ammo. Just out of curiosity, what do you pay for, say, CCI Standard? Here we can find them for 8 dollars/100 pcs if we are really lucky, some stores charge the double. Even the bulk ammo isn´t seldom cheaper than 8-10dollars/100pcs.

[salt27]

Anders, When CCI 22LR can be found it is about the same as what you are paying and a 100 round limit.

Sorry about mudding up your build diary.

  Don

[grumm441]

Thanks guys!

I spent my birthday at home with an ill daughter, nothing serious so we had a good time putting most of the outdoor summer stuff away and doing some rimfire plinking with my 10/22 in the back yard.


Cheers!
/Anders

The ammo is still cheap and easy to get in Aus, if you have the correct license, however the government took all our 10/22's off us
so plinking is done at my Dad's place with an air rifle, or the 22 Sportco I bought when I was 15.
G

[Peter Jack]

Thanks guys!

I spent my birthday at home with an ill daughter, nothing serious so we had a good time putting most of the outdoor summer stuff away and doing some rimfire plinking with my 10/22 in the back yard.


Cheers!
/Anders

The ammo is still cheap and easy to get in Aus, if you have the correct license, however the government took all our 10/22's off us
so plinking is done at my Dad's place with an air rifle, or the 22 Sportco I bought when I was 15.
G

Grumm, could you explain that little statement about the government taking all your 10/22's a little further. That one really bothers me.

Pete

[Mobacken Racing]

The ammo is still cheap and easy to get in Aus, if you have the correct license, however the government took all our 10/22's off us
so plinking is done at my Dad's place with an air rifle, or the 22 Sportco I bought when I was 15.
G

That is disturbing, sure the EU is trying its hardest to ban semi automatic rifles (for us law abiding citizens that is, illegal AK´s and pistols are pouring into the country as we speak for god knows what future purpose) but I can´t see how they could ever withdraw a legitimate gun license like they seem to have done in Australia.

Handheld firearms are on a 5 year license here in Sweden, so depending on the politics and stuff you might be declined to renew it when the time comes. The Ruger Mini-14 was banned as a hunting rifle after the Breivik mass murder in Norway so who knows what might happen in the future?

Rifles licenses are for life so far unless you go and do something particularly stupid and get caught.

[Mobacken Racing]

Anders, When CCI 22LR can be found it is about the same as what you are paying and a 100 round limit.

Sorry about mudding up your build diary.

  Don

Ok, a 100 round limit sucks but I can see the reason for it since the US supply is low. I might have to stack up a couple of thousand rounds then just in case.

No problem with straying a bit off topic when it is guns we are discussing, I am about to head to the workshop in an hour so hopefully we´ll be back on the gas turbine track before I call it a night.

[Mobacken Racing]

I have managed to fix my 3D printer which has been broken for 6 months and it has already started producing some bike parts, I´ve 3D modeled and printed a nylon bracket for the fuel, oil and preheat switch board so it can be mounted directly to the tubular frame. It was mounted to the side of the intake air box earlier.



The bracket turned out really well, I´ve spent lots of time fine tuning the nylon printing settings and after numerous crappy prints they are finally starting to come out like I want them to.



Until now I haven´t had any fuel pressure readings on the engine, it is a very useful thing to have both for adjusting the idle and as an indication that something is wrong with the engine, like a clogged injector. I made a small aluminum filter coupling and threaded it with 1/8"NPT to accept a glycerin filled gauge I ordered on Ebay, later I might fit a pressure sensor and fit an electric fuel pressure gauge on the dashboard but for now I settle with an analogue gauge in line with the fuel filter.



Since it takes many turns to fully open and later close the scuba tank valve I added a ball valve to the tank coupling, this will allow me to operate the impingement air very fast which will save lots of air.



Cheers!
/Anders

[grumm441]

The ammo is still cheap and easy to get in Aus, if you have the correct license, however the government took all our 10/22's off us
so plinking is done at my Dad's place with an air rifle, or the 22 Sportco I bought when I was 15.
G

Grumm, could you explain that little statement about the government taking all your 10/22's a little further. That one really bothers me.

Pete
[/quote]

I'll send you a PM
G

[Mobacken Racing]

Last night I couldn´t for my life figure out how to place the oil pressure sensors, so I decided to give it some thought over night instead of just throw together some half arsed solution.



As I wrote earlier I have decided to remove the oil filter so I needed to fit the Hobbs oil pressure switch and the Autometer oil pressure sensor on the line between the regulator and the engine.



I am glad I gave it some extra thought since this turned out really well, gas turbine feng shui sort of.



Cheers!
/Anders

[Mobacken Racing]

Before I change the syringe fuel injectors to the new and hopefully better design I need to know how uniform the old injectors is flowing, so I rigged everything today and flow tested the syringe manifold, the uppermost injector was labeled "1" and then counting clockwise watching from the rear of the engine.



I let the fuel flow until the cups were roughly filled to the half, then I weighed each cup on the kitchen scales and wrote the numbers down.



I knew from the propane flame test that one syringe (nr.6) was partially blocked, but that test didn´t at all indicate that there is almost 20% flow difference between the second lowest flowing syringe and the highest flowing one.



The more or less random bending of each syringe might have caused this flow variation, it will be very interesting to see if the new injectors will produce a more stable flow. They give a fine kerosene mist instead of a solid jet so I have high hopes that the engine will run better with them installed.

Cheers!
/Anders

[Mobacken Racing]

Last night I started to swap the old syringes for the new ones, I keep the manifold pressurized by shop air while desoldering and sanding down the area around the holes to keep dirt from getting into the manifold.



Desoldering in progress!



I used a pair of flat nosed pliers to bend the end of the syringe, the resulting fuel spray has a comb shape to it which turned out to be consistent for all 18 I made.  



Here I have just silver soldered the first syringe.



I place it up against the wall of the evaporator so the spray covers as much of the tube cross section as possible.



Only 17 left to do, a couple of hours work and then a proper flow test to check that all of them flow equally much.

Cheers!
/Anders

[Mobacken Racing]

When my fiancee fell asleep I sneaked out to the workshop for a late night date with Carlene Carter and some silver soldering.



With all of the syringes soldered and bent to shape I rigged everything for a new flow test, I hadn´t planned for it to go this fast since my fuel pressure gauge hasn´t arrived yet.



It was very difficult to get a good shot of the kero spray, but it looks very promising for sure. All of the 18 syringes produce an identical pattern as far as I can tell.



I let the pump run for 3 minutes as hard as I could before the kero started to mist out of the evaporator inlets, the total kero flow for the manifold was 1118g/min or rougly 1.4liters/min which is about what the engine needs. The flow difference between the lowest and the highest flowing injector is only 7% and most of them is within a few % so very consequent flows with the new injectors!



Big surprise, I expected that I would have to exchange at least a couple of injectors before the flows would be decent all around the manifold. Now I can just start to assemble the engine again for a test start, just need to take a peek at the wear pattern in the gearbox first.

Cheers!
/Anders

[nanno]

Great work Anders!

I have been following your overhaul-schedule a bit and you seem to run into those blockages quite a lot? Any idea to why this happens? Is the solder melting due to the heat or is it just some dirt/debris/residue in the fuel system?

(Sorry if you have answered this question earlier, but I couldn't find an answer so far...)

Cheers,
Greg

[Mobacken Racing]

Great work Anders!

I have been following your overhaul-schedule a bit and you seem to run into those blockages quite a lot? Any idea to why this happens? Is the solder melting due to the heat or is it just some dirt/debris/residue in the fuel system?

(Sorry if you have answered this question earlier, but I couldn't find an answer so far...)

Cheers,
Greg

Hi Greg,

I don´t know for sure, but my guess is that the kero boils off inside the fuel manifold from the heat stored in the engine after a run, this results in soot particles that end up blocking the small diameter syringes.

The new syringe injectors are larger in diameter than the old ones, so hopefully any dirt will pass through them into the engine. I will take a reference fuel pressure at 1bar boost pressure when the engine first is started, this way I can see if there are any blocked injectors. If so the fuel pressure needs to be higher to get the engine up to the 1bar boost pressure.

The JU-02 engine I am in the process of building will have an external fuel manifold so I can remove any single injector for inspection and cleaning without having to remove the engine from the bike.

Cheers!
/Anders