Evo III

[alan]

Here I'm drilling the hole for a large aluminum coupling that will act as the cap.



This is the piece for the oil drain on the turbo.


I used the famous shurflo pump as my oil pump and a $30 fuel pump that is capable of 60 psi.

[alan]

I have to skip ahead a little because I didnt take pictures in between.


Here is when i first finished the project (you can see in the back-round my truck decided to sink into the driveway when i needed it to help move my newly complete and heavy engine ).


P2 Fuel Oil



My nice large oil cooler that i got for $30





Here is the AC ignition transformer that i use.

I really want to hook up a coil that runs off DC, but I am confused on how to actually do it.

From what i learned in physics an ignition coil from an automobile only produces a high voltage when a current first flows through one coil and then again when it stops flowing.

Is this correct or am I wrong missing something?

[Johansson]

Here is a drawing of a simple 12V ignition using a car spark coil and a turning light relay that my friend Olov has made, unfortunately written in swedish but what the text at the bottom says is that you need a capacitor (the square black thing in the upper right corner) and that the power switch has to be on the +12V.

The upper relay is a switching car relay and the bottom one is a turning light relay.

[alan]

Looks simple enough for me to make. Thank you Johansson. Does the capacitor have to be of any specific value?

Sorry, I havent been educated in electronics yet.

[wolfdragon]

Just use an automotive condenser (capacitor) that is meant to be used with a "points" style ignition and you will be fine, they are cheap.

As for the value i think they are like 0.02 uFd or so, not much but they are rather high voltage

[Johansson]

No idea, but probably not. The one he use is perhaps 20mm in diameter and 30mm long, came from a snowmobile ignition I think.

I am no fan of electronics either, I try to avoid it as much as possible since my previous pursuit of knowledge regarding it normally resulted in a small puff of smoke and a suddenly lighter purse... ;D

[alan]

When i go home for spring break i will wire that circuit up to replace the AC ignition.

It came time to start her up for the first time. I wanted to practice the start up without the turbo and it was a good thing did because the .5" valve was very very sensitive.



Then i was confident enough to start the engine for the first time. Sorry i don't have a video, our camera didnt have any batteries

I ran the engine on propane first then switched to kerosene.
with the kerosene i was able to run it up to 25 P2. Everything worked out just fine.

Then i took it apart and found a few problems with the design



The evap tubes are 316 stainless.


Luckly the turbine survived ;D


its a good thing this little guy didnt go through


John explained to me that it was from fuel burning outside the FT. Which came from from fuel dripping back through the evap tubes.
Plus the propane that was injected outside the FT at the injector cap ended up flowing out and around the FT wall.

[alan]

To fix the problem with the propane i simply drilled through the CC cap and FT cap and used a pipe fitting to supply the propane directly inside the FT.





This made a huge improvement on the ignition and preheat cycle. I had poorly placed my spark-plug which made it hard to ignite the fuel, but now the propane flows directly towards the spark.


I also learned that i can use a smaller tank from something like a blow torch or lantern for preheat.

[racket]

Hi Alan

You certainly were working under adverse conditions , you've got to be congratulated on getting as far as you have with the engine :-)

Cheers
John

[alan]

Thank you John

I also installed a purge valve in the CC cap, but I did not take a picture of it.

After I cleaned everything and put it back together I started her back up for another round.

This time I used a little propane tank from a lantern to preheat the evaps. Once i got it running on kero I think i ran it up to 20 psi then shut it down.

This time there still was overheating but not as much. Unfortunately one of my evaps did not survive.

If you look there is a hole in the first stem


Somewhere in my calculations I doubled the length of each evaporator. So I bought some more tube and cut it to the Correct lengths.


To reduce any restrictions in airflow I cut off the intake elbow, opened the hole and had a diffuser welded on.


I dont have a picture of new diffuser installed, but ill tell you now, it is a little rough looking lol.


This is currently where I am at.

I gave these evaporator pieces to a welder, but he didn't get them done in time and i had to move out. I am not sure if the evaporator pieces are done or not or even in the welders possession. I hope he did not scrap them.

[alan]

Hello everyone, just a bit of an update here.

I went home for spring break last weak and two of my high school teachers asked me to give a demonstration of my jet, so i was able to get a short video of it. Unfortunately the camera cut out after 1 minute like it always does

youtu.be/by544lIJNFw

I was not able to get my new evaporator parts back yet, but maybe next time.

I used the circut that Johansson gave me to drive an ignition coil and that ended up not working, so I will do some more work with that later as well.


The main issue I have with this engine is that it overheats at around 20psi. There is no temp. gauge but the turbine and housing glows a dull orange. I got a book about gas turbines and I read the section about water injection and I am thinking about going that route.

I need to obtain further information about steam/water injection upstream and downstream of the compressor. Feel free to recommend any books, i have access to all librarys in the state.

[Johansson]

Injecting water to cure an overheating gas turbine is like scratching your ass to cure hemorrhoids, it works for a while but it doesen´t solve anything...

I would suggest that you skip the drilled bolt injector and make an injector manifold with a separate syringe needle for each vapour tube, my guess is that the fuel doesen´t mix evenly in the end cap and some tubes get more fuel than others and the one with less fuel overheats.

That would also fix the problem with fuel leakage outside the flame tube, as it is now fuel is spraying everywhere since there is no pressure difference between the outside and inside of the end cap that holds the fuel in place.

[alan]

I do agree that i need to make an injector manifold with separate syringe needles to fix the problem with uneven fuel distribution and leakage outside the flame tube. I might also need to mount the combustor so it sits horizontal instead of vertical to ensure that fuel wont drip out of the evap tubes. My only worry with that is if anything decides to melt it will exit through the turbine and damage/destroy it.

The reason for water injection is because of the other problem I have with the turbine section being on the large side with an AR of 1.15. Plus it has a reflectively open blade angle, which requires more energy from heat, but if I increase the mass flow by adding water then a lower TIT can be obtained.

It might make it less fuel efficient, depending on whether I decide to inject the water upstream or downstream of the compressor, but I have not found another way to solve this problem. I am open to new ideas though