First DIY build. Variable vane turbo?

[arsefast]

Hi.
I have decided to try and build my first jet after watching this space for a while.

I managed to snag the turbo off of a iveco lorry. Inducer is 65mm.

Plan is propane to start with. Then a kero afterburner. Then possibly kero for both. But gotta get it running first.

Only after purchase I realised it's a variable vane turbo. It was cheap enough that I could look for another if required but I figure might as well give it a go.
I was thinking leave the vanes at maximum open to get as much mass flow as possible through the turbine wheel.

[racket]

Hi

Generally in the beginning its best to fix the vanes at half way , not too tight ......not too open , this will provide a position that shouldn't get you into trouble on the first spoolup .

Max open might lead to high temperatures , too closed and the comp might go into surge along with high turb temperatures .

65 mm is getting a bit large for just propane unless you have a very large propane cylinder , the normal 9kg-20 lb BBQ size probably won't get you to full power, our engines use a lot of fuel .

Once the engine is running and you've become familiar with it and you want to add a jet nozzle to put backpressure on the engine , then you can start to "adjust" the variable vanes to optimise the configuration and thrust.

All the best with the build :-)

Cheers
John

[arsefast]

Thanks that makes sense.
I am looking at putting a threaded rod on the actuator and some jam nuts so can set the vanes to whatever I want.
Fuel delivery shouldn't be an issue. I have some 60kg propane bottles from a gas forge I built. I would be very impressed if I iced those up.

For a first engine I am thinking mild steel combustor and housing.
I would like a stainless one but can't find stock in the right side that isn't prohibitively expensive.
And I am already eyeing up a 125mm HC5A turbo for a second build so need to save some pennies for that.

Lastly for the p4 measurement is a regular pressure gauge sufficient. And is it more important to measure TIT or TOT?

Thanks
Tom

[noshell]

Ive built one with a variable vane turbo. The vane position isnt as crucial as youd imagine. It runs very nicely, its a well matched compressor inducer/turbine exducer though.

Edit: mine dies with vanes max open and starts easier with vanes closed.
As i said though it is not like mm crucial.

[racket]

You really need stainless for the flametube , outer can in mild steel is fine , if you do use mild steel for the flametube , make it out of a decent thickness to prevent it burning away .