New member and first DIY Turbojet build

[enginewhisperer]

there's normally some play. If wheels are not touching the housings it should be fine.
Even if they are, it'll usually be ok with decent oil supply


A cheap oil pump that works ok for turbines is a vane type power steering pump. They're easy to belt drive using any convenient motor. I've used a 24v 300w scooter motor in the past with good success.

[racket]

You need the returning oil to pass over a perforated de aeration plate , theres always smoky fumes with the returning frothy oil

[The Lazy Destroyer]

Changed to 10w30. Ran it for a couple minutes and the oil looked way better. No bubbles or frothy oil. Seemed like it smoked a little less also.

The oil pump I have (fuel pump style) runs at 50 psi all day until the engine runs then slowly creeps down to 20 psi. So I kept it at a short run and at lower P2’s (<7psi). Will probably look to change this pump out to something else.

But for now pretty happy, this thing starts right up and runs pretty smoothly. I’ll keep working on it but I feel this is a good place to be at. Need to shift to some other projects but at least I can say she runs now!

[The Lazy Destroyer]

Been a while since I ran it, so I fired up the turbojet for a bit this past weekend and took some video. 

Youtube link: 
youtu.be/3_sNPfrNYbU?si=nXZmVsTUGIco7ihb

[racket]

Thats one very nice clean build :-)

[britishrocket]

Hello, This is such a superb build and I'm finding it inspiring. I have a few questions though.

The 10psi boost (so 24.7 absolute) suggests a compressor pressure ratio of 1.6.

The size of the compressor inducer gives a maximum air flow rate of about 0.65lb/sec or 39lb/min. I have looked at T3/T4 compressor maps for various different trim values and I can't find one that would flow anything like this at a compressor PR of 1.6.

What am I not seeing?

Thanks, Carl.

[racket]

Hi Carl

Yep , at a 1.6 PR the flow will be roughly half the full rpm flow , and as you said , a comp with a 50 mm inducer will flow ~35 lbs/min, or the rougher 12 lbs/min/sq inch of inducer, so maybe up to ~20 lbs/min at 1.6 PR

Cheers
John