My first build, started ~8 years ago, no ignition till now

[andreirs]

Hi all. I think I first decided to build a jet engine when I saw one in TV, lots of time ago. Around 2010 I got a smoking turbocharger from some "ebay like" website we have here. It is a Schwitzer S2EL, used in truck diesel engines, Schwitzer is now part of BorgWarner. At that time the turbocharger had a problem, the compressor wheel was a bit loose from the shaft...? Anyway I went to a guy who rebuild these turbos and he charged me in something like, I don't know how much that would be in dollars, but lets say almost 100$, to fix the loose compressor and oil leak. After some time I found a big tube to build the chamber and slowly built it. Some 3 weeks ago I had my first jet engine set to test.



I run the oil pump and turned on the air, which is a vaccum cleaner working in the other direction. No fuel or spark on. But all I got was some massive amount of oil at the wall behind hahah. So I got a repait kit for the S2EL and changed the parts. Also discovered the guy only tightened the compressor wheel, removed the broken piston ring and never put a new one. I didn't go back there because since he first worked on it, some 5 years went by. I also had the same loose compressor wheel problem now, but this time I was able to figure it out. It is a big snap ring that keeps all together, it has different sides, chamfer goes outside. Here is a pic of me rebuilding it.



After all this I changed some other things, the fuel pump is now just a 40mm tube with a bosch 12V fuel pump and the oil pump got a lot smaller. But I can't get it to ignite. It looks like a flamethrower outside the chamber, but when I put it together, no flame. Today it looks like this. I plan to improve it latter, but first I will try to make it start.

[andreirs]

I'm also uploading 2 short videos to youtube which I had on facebook... Maybe they show something I'm not noticing.

Here is the fuel pump burning some kerosene.

www.youtube.com/watch?v=1gUkVo4gRwg

And here, the turbocharger spinning without fuel, just oil and air.

www.youtube.com/watch?v=kP4-KVPK8Vw


Tomorrow I will test the burner outside the chamber again, but with the flame tube on place. The was no flame tube on the first video. And maybe I will also change the spark plug for a diesel glow plug. I had more sucess testing with it outside the built.

[turbo]

Mar 26, 2019 18:43:46 GMT -5 andreirs said:

Hi all. I think I first decided to build a jet engine when I saw one in TV, lots of time ago. Around 2010 I got a smoking turbocharger from some "ebay like" website we have here. It is a Schwitzer S2EL, used in truck diesel engines, Schwitzer is now part of BorgWarner. At that time the turbocharger had a problem, the compressor wheel was a bit loose from the shaft...? Anyway I went to a guy who rebuild these turbos and he charged me in something like, I don't know how much that would be in dollars, but lets say almost 100$, to fix the loose compressor and oil leak. After some time I found a big tube to build the chamber and slowly built it. Some 3 weeks ago I had my first jet engine set to test.



I run the oil pump and turned on the air, which is a vaccum cleaner working in the other direction. No fuel or spark on. But all I got was some massive amount of oil at the wall behind hahah. So I got a repait kit for the S2EL and changed the parts. Also discovered the guy only tightened the compressor wheel, removed the broken piston ring and never put a new one. I didn't go back there because since he first worked on it, some 5 years went by. I also had the same loose compressor wheel problem now, but this time I was able to figure it out. It is a big snap ring that keeps all together, it has different sides, chamfer goes outside. Here is a pic of me rebuilding it.



After all this I changed some other things, the fuel pump is now just a 40mm tube with a bosch 12V fuel pump and the oil pump got a lot smaller. But I can't get it to ignite. It looks like a flamethrower outside the chamber, but when I put it together, no flame. Today it looks like this. I plan to improve it latter, but first I will try to make it start.

I have used a taser unit and modified it for a spark plug . Cut the earth tail off leave center one it works well

[racket]

Hi Andrei

A couple of points I should mention , the air delivery tube between comp housing and combustor has a very sharp "elbow" in it , the air is moving very quickly through the tube and upon meeting that elbow will create backpressure on the compressor , you need a smooth bend at that point .

Secondly , please use metal tubing for pressurised fuel and oil lines anywhere near the combustor , soft lines will fail due to the heat with the potential for a "fireball" if fuel/oil hits the red hot turbine scroll.

May I suggest you plumb some propane to a suitable "radial injector" in the flametube rather than use kero .

Also , how is your flametube configured ??

Cheers
John

[andreirs]

Hi Turbo, good idea, these tasers are not available here. But you gave me an idea.

Hi John. Ok I will cut that out and try to find a piece of already curved tube on the junkyard. They have a lot there.

Ahh I didn't thought that using rubber tubes was a good idea but I could not find copper conections around, then I thought "if I manage to turn it on, I will do a overhaul on it next". Not sure if this is a good idea... Haha ok I will get the metal tubes.

My flametube was calculated using a software from yahoo groups about jet engines. I have never realised how to post there and then find the post latter, but last time I visited it, I was young and dumb. I drilled 20 5mm holes as primary, 10 6mm as secondary and 8 8mm at the end. But since that cone begins round at the combustor and ends quite rectangular at the turbine, there are 4 big gaps around the end of the flametube. That is why I didn't made more holes at the end. Tomorrow I will have to fix my pc monitor which just blew up, but after that I will take a pic of the flametube. Thanks!

Oh propane. I can't use right now, the "cheap" tanks have only a spring valve and are kinda dangerous. The other tanks like from US are very uncommom here. I will see if I can find a safe way to storage propane.

[racket]

www.ebay.com/bhp/high-voltage-generator

[andreirs]

Today I did a little modification to the fuel nozzle and set the "pressure" to around 50psi. I could not find my neighbor who works with copper tubes. Tomorrow I will try again. Now it smokes and spins up for 1 second and then shuts down. It is weird because once I turn off the fuel pump it starts the combustion. Then I turn it on and meh, fire goes off. But it was cool and I really need those copper pipes John told me to find, things got hot really fast. Any idea on kerosene consumption? I think I will buy a fuel injector from electronic ignition cars, today ones. But I have no idea if those injectors will provide enough fuel, then I could buy a injector from older models which only use 1 common injector for all pistons. But then again, if I buy one which is too big, I won't have enough pressure at low throttle to make it spray. I'm not sure if my problem now is lack of fuel or too much fuel. But I think it is the first option...


Here is the flame tube.





That gold ish part is the brass fuel nozzle and the black thing to the side is a spark plug that comes in at an angle. It throws the spark over the nozzle to a piece of metal on the other side, causing the arc to go right thru the fuel. The spark is around 1 inch or ~25mm from the nozzle.

[Deleted]

Hi, nice to see you here..... glad you found your way from facebook

All The Best
Andy

[racket]

What diameter is the compressor wheel inducer ??

[andreirs]

45.05mm. Hub is 15 if I'm not mistaken, will check tomorrow, too dark there now.

[racket]

With that ~45 mm diameter inducer you'll flow ~35 lbs/min or 16 kgs/min of air , so ~16 kgs of fuel per hour required, or ~20 liters/hour , or a bit over 300 ml/min at your maximum fuel pressure , your fuel nozzle flow rate will need to be checked to see how it conforms to that rate .

[andreirs]

Many thanks John, tomorrow, I mean today, I will remove the pump and measure the flow of the nozzle using water. I already wasted 2 liters of kerosene and no run. Now that 300+ (333.33333...) ml really gave me a base to start with. Hm I guess I should go read a bit about fuel mix, sorry. Since today I can't go there, I will find some efi fuel injector datasheet to look for flow rates. Thanks again.

[andreirs]

Sorry for double post, this is an update with last info. Looks like efi fuel injectors go up to some 90ml/min. Most give way less than that. I woke up today and went to the shop. I discovered good and bad things I think. Good things are, that the nozzle is really spraying fuel instead of a line stream as some time ago. But not sure if "small particles". I tested using water. Also it is giving more than expected, 300ml/25s or 720ml/min. I don't actually know if that fits in the good or bad discoveries... Bad thing are, once I barely open, till the end of the opening, it sprays the same amount as you can see on the video. Also I think the spark plug is too close to the nozzle? Hmmm errrm, I don't know what to do now, I think I will try to fire it again with very small valve opening and record... Need to go work on something else a bit. Thanks guys.

www.youtube.com/watch?v=hmn-t3zaCRI

[racket]

Hi Andrei

For starting and idling you'll be needing closer to 100 ml/min , so you'll need to test for fine atomisation at that flow if you expect to get the engine spooled up .

Cheers
John

[andreirs]

Hi John. Thanks for all this help. I managed to lower it to 350 400 ml/min. Had to use my advanced hammering techniques. I don't have any drill smaller than 1mm, so I got a center punch and hit it around the nozzle hole to make it smaller... I could not work too much on it today. I also drilled 4 more holes at the primary part of flame tube. Increased secondary from 6 to 6.5mm and tertiary from 8 to 10mm. Now only the tertiary holes are smaller than calculated, but I still have a gap at the end. Maybe I can fire it again tomorrow... Oh first I will install the diesel glow plug ahead of the spark one. Not sure where, but I think between primary and secondary... That plug easily goes thru the radius of any diy diesel turbocharger based jet.