Project Radial Jet from a 105mm Holset

[longjohn]

I've biult a few jet engine creations in the past the last being a rather crude external combustion chamber TO4 based jet engine with afterburner, running kero scooter.
http://www.youtube.com/watch?v=oWXQUgL0Rt0 Bit of a laugh, anyway its got sleeve bearings and the combustion chamber doesnt burn cool enough and its heavy.
I have come across a Holset 105 turbo, its never been used, picked it up from ebay for 150 dollars. Easy, now I wanna biuld a proper axial jet.
It has to have ball bearings and it has to have no external lubrication system. It has to use the oil/fuel mixture to cool and lubricate the bearings.
I've never done anything like this before, so I'm here to learn.
I am concerned about the combustion chamber size/length, and am considering a shaft extension to make the chamber longer so the flame has plenty of length to go out before it hits the turbine.

[longjohn]

Ive pulled it down and taken measurements.
Rocketrotorman has emailed me and suggested he may be able to arrange castings for the front case and diffuser. Being people in the know im probably going to take up their offer.



Sorry ash powers, ive stolen your plans! Hope you dont mind. Im just using it as somewhere to start.

[Bounce]

Hi John!

Wanting to build a GT with a complete turbocharger rotating assembly myself, I found this arrangement out of the Kamps book worth trying (little blurry scanned and in German but one should get the idea). Will make the turbine longer, but saves you the troubles of a too short CC and building a shaft extension. If you find that reverse flow CC as cool as I, Dane's gallery in the yahoo.group might also be worth looking at.
Hope I could give you some idea to think about ;)

Regards, Dennis

[craigclavin]

Hey this is great, i was going to start exactly the same project as soon as i get the guy from Heward micro-jets jets to reply about the pheonix plans. I intended to scale up their plans around the turbo charger then build something similar.

I was actually thinking about turning the front and back covers down and keep them as very accurate compressor and turbine covers. See the attached pic for a better idea of what i mean
I was going use the existing journal bearings but gave up the idea after hitting oil containment issues - i cant seem to find lip seals to deal with 400 degrees lol

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[Ash Powers]

That holset turbine looks awfully similar to the TV94 turbine wheel I'm using for my TV94 TurboFan project. :)

Can you get exact dims on the compressor wheel and post them?

Also, just a side note, this type of engine is not called an "axial engine" as both the compressor and turbine wheel are a radial design, not axial design. :)

[racketmotorman]

Hi Ash

Yeh pretty similar to our wheels , bit bigger in the exducer and comp quill, but slimmer in the mainshaft , clipped as well .
Should be a reasonable match for that 105mm comp inducer if the turbs inducer tip height is >21mm

Nice big assembly :-))

Cheers
John

[craigclavin]

Can you tell me if the following is correct
There might be a chemically etched part number on the shaft and wheel.
From your pics the turbo looks like an HC5A, with a 3521034 shaft and wheel. Compressor wheel is 3523546. From the drawings the turbine wheel has an exducer diameter of 111.7, and an inducer of 129 with a blade tip height of 40.75

The compressor wheel has an inducer of 129.5 and an exducer of 103.9, with a blade tip height of 40.33.

Hope this helps!

[longjohn]

Ok a radial design hehe.
The part number on the back of the compressor is 3523546
Same as yours craig!
The outer diameter of the comp wheel is 131mm

The exhuast turbine and shaft is yes...a 3521034 !! Same again!

So what does this mean? Will be easier for me to get a start somewhere?
Bounce : I like that reverse flow design idea. IS that design a bit less effiecient, due to the gasses turning direction twice? Or is it better, because the combustion chamber gets some extra heat from the exhuast?

Rotorman: id like to persue the reverse flow idea, as it wont mean extending the shaft. It also means a larger engine with larger combustion chamber!!

[craigclavin]

Lol, they will be the same, i looked up the turbo number that you can see on your turbo photo and pulled all the details and drawings from there.
Did you not get the pm i sent you explaining that i work for Holset? Incase you dont know, Holset doesnt exist no more - its now Cummins Turbo Technologies

It just means if there is any dimensions you need that you cant take from the parts - all you need to do is drop me a message and i can get them - it will save you having to mess around with radius guages etc
and what the hell, im really chuffed somebody is using Holset stuff and i get to say i work there. Adds a little excitement to my job!

[Bounce]

Ok John.... ;)
I think it has a little less performance than a "normal" axial turbine and straight CC (says so in the German Wikipedia) but if you look at Ash's turbine, you have the same bent as in the design I want to use except that the gases in his sketch kind of keep their original direction while "mine" are bent 180°. I dont think the hot exhaust will boost any performance since you have to watch your TIT/EGT anyway ;)
BUT I'm not sure as I'm new to gas turbines and will only gain experience with this build.

there's only one way to find out.....
and I'm going to do (or just hope so) ;)

[racketmotorman]

Hi Craig

Am I reading you correctly when you say the comp inducer is ~104mm and the exducer is ~130mm, 64 Trim , thats not much "tip" on her , guess she's more of a lowish boost job .

Could you give us some info on the larger Holset high compression comp wheel ??

Cheers
John

[craigclavin]

Ill double check on Monday when im back for work. If this helps the turbo probably came off a high horse power engine, possibly explaining the low boost.

[racketmotorman]

Thanks Craig

Look forward to that :-))

Cheers
John

[longjohn]

Ive taken accurate measurements and sent the photos and measurements of the compressor wheel to John Racket man.

John, Your freind cameron who has your go kart now visited me yesterday and since he was talking about a local meet up here sometime, I thought since id just put my old jet scooter back together id give it a run. Cameron liked the way the scooter was biult and wired up and we gave it a run. It ran well, but I took it out last night for a spin with a mate who was wanting to ride it and it was realy running poorly. I'll have to check everything later after my work trip this week to see what happened.

[craigclavin]

Am I reading you correctly when you say the comp inducer is ~104mm and the exducer is ~130mm, 64 Trim , thats not much "tip" on her , guess she's more of a lowish boost job

Hey Racketman - ive checked again and it seems to be correct, which wheel do you want me to check now? A larger one with a similar trim?