10/108 engine

[racket]

Hi Guys

I've been bored

So dug out some bits to play with, the Allison C20 second stage turbine and NGV that have been boxed up for years without any opportunity for its use because of its 163mm diameter but limited flow area , but the very low Trim TF15 billet comp wheel which came with the CHRA has a 170 mm exducer but only a 108mm inducer with a rather large hub , so also a limited flow area ................maybe an opportunity for a bit of match making and possible marriage

Time for some maths methinks

A few pics






Cheers
John

[dieselguy86]

Hey John,

Didn't you buy a tiny turbo a few years ago?

Have a gt62,122mm comp and some bearings I could send to you to have some fun with.

[racket]

Hi Joe

LOL........you'll be needing them one day ;-)

I did buy a tiny turbo , must be hidden away somewhere , this memory of mine is getting worse , I've got boxes of stuff I haven't opened since I moved here 11 years ago , heaven only knows whats in them , I guess the kids will find out before they throw everything into the skip bin one day .

The maths for the Allison wheel are looking promising , the NGV throat is fairly large in relation to the wheels , 5.2 vs 5.9 sq ins for the wheel , so limited pressure drop in the NGV but a choked wheel.

Cheers
John

[stoffe64]

WOW, Another engine COOL!!
This i must follow!
Cheers/Stephan

[racket]

Hi Stephan

Nope , I'm only filling in time whilst waiting for my turbine wheel to arrive .

As there hasn't been much activity on the Site lately I thought I'd contribute something :-)

No more engine builds for me .

Cheers
John

[racket]

Hi Guys

The turbine wheels have required more work

The second stage wheel has a stub shaft that drives the comp , theres a drill hole part way up that shaft and through from the wheel , its a bit under 18mm dia , now an aero engine turb wheel is a precision bit of gear , but I found that bore wasn't running true to the rest of the wheel , so I needed to rebore it true .

A jig was turned up so that the 46 mm dia labyrinth seal located the wheel radially in a hole in the jig, and the wheel rim at the base of the blades being machined true, allowed for axial alignment against the jig .

Now all I had to do was workout a way to hold things in place during machining , a coupla clamps did the job once I fitted tapered wooden wedges under them .

Things were looking good ..............I was able to get to the bore and machine it out by ~0.3mm to get a true finished surface , and I was able to square off the end where the stub shaft had been side grindered off .

The first wheel was the hardest , but slow and steady with a tipped tool and the job was done , so finished off the second "spare "wheel in quick time






Cheers
John

[andym]

Nice work John..... :-)

[racket]

Hi Andy

Thanks

A coupla pics of the other side after removing the laby seal and curvic .





Just an ordinary turbine wheel now

Cheers
John

[WilliamTQ]

Wow John how many projects have you got on the go at one time?

[racket]

Hi William

LOL..... Too many :-)

Cheers
John

[WilliamTQ]

Still waiting on turbine wheel for the 11/127?

[racket]

Yep , its in the Post somewhere

[andym]

May 9, 2023 4:09:12 GMT -5 racket said:

Yep , its in the Post somewhere

From what you have told me about your post over there ...... it could be some time between now and summer
But this would be an interesting project..... what numbers for total thrust ?

[racket]

Hi Andy

Haven't thought about the thrust potential, but with a potential 3.3 lbs/sec flow , it'd have to be close to 200 lbs

Cheers
John

[turboron]

John, does this mean we are no longer limited to the T94 radial inflow turbine for our maximum horsepower Gas turbines?