ball Bearings

[sven]

Hi

I got myself a Holset turbocharger HY55v from truck, and Im like to start building a jet engine from it. Im gonna use parts from this turbo(shaft, compressor wheel and tubine wheel) First big problem to me is that I dont know witch bearing to use, I was looking these bearings are they good?(for this size engine)
www.acerracing.com/ball_bearings/12x24x6mm_Ceramic_Ball_Bearing_|_6901_Ball_Bearing-1140-30.html
When turbine saft is 12mm, is 12mm middle hole bearing will do,or I have to leave some tolerance for expansion?(or better is tight fit?) Same thing with tunnel and bearing outer ring?

Second problem is how is the best to make shaft tunnel and lubrication system(fuel oil mix?) to make bearings last longer than few minutes. I have quite primitive tools to but good will to build it.
Any good info,pics are welcome!

Thanks, and hope you understand my bad language.

Sven from Estonia

[racket]

Hi Sven

Are you going to use the jet engine in a RC aircraft ??

If the engine is going to be a ground based unit where weight and size isn't a problem then I strongly recommend that you use the standard journal bearings as setting up a turbocharger rotor in ball bearings requires additional work to dampen rotor dynamics( vibration) otherwise the ball bearings will soon fail .

Ball bearings at extremely high speeds have very complex requirements .

If you don't already have this book .....http://shop.traplet.com/product.aspx?c=183 I'd recommend you purchase it .

Cheers
John

[sven]

Thanks John,
Yes, this engine going to be a ground based unit. I take your advice and try to make it on standart journal bearings. Making a tight sealed chamber for journal bearings will be challange itself

Also thanks for a book tip!

Sven

[racket]

Hi Sven

Why not just use the standard turbocharger and simply fit a combustor .

Cheers
John

[sven]

Hi,

I already made one small turbocharger based combustor engine, Now I try to make it in one piece, more jet engine like turbine.
(maybe its going to power my motorbike in future)
My holset have a big middle section for water and oil, anyways its not practical at all, but my friend who dealing with volvo trucks said that, he have good size turbocharger, with small middle section and with in good price its mine.
It is low mileage holset he551
www.dwenginecomponents.com/Pages/ItemProfile_Detail.aspx?ItemProfileId=IHL170-032-0301
I think its good for use this turbo(all except housings)

Let me know is it good idea!

Greetings Sven

[racket]

Hi Sven

Thats a nice small centre housing on the 551:-)

Though it looks like the turbine scroll has a "variable" device , it'll depend on the actual wheel sizes as to whether the rotor will make a good engine or not .

As long as the turbine wheels exducer ( outlet) area is ~20% bigger than the compressor wheels inducer ( inlet) its a reasonable match and should produce a working engine .

Cheers
John

[sven]

Thanks

Exducer is 80mm and inducer is 70mm,these are rough measurments.
Have to do back home some math and figure it out.
Sven

[racket]

That should be OK

[sven]

Hi
John, I got nice stainless steel tube with wall thickness ca 1.5mm is it goo enoguht to built from it outer casing for my tubine? Or should it be thicker?

[racket]

Hi Sven

1.5mm is thick enough .

Cheers
John

[jdw]

Here is someone's build you may want to look at i believe he still uses the turbo core in his engine. Look in the info tab under the video and there is a like to some photos of his build. www.youtube.com/watch?v=8gJFW1mih9E

[wolfdragon]

The core was slightly modified on a lathe/mill, but no more than some of the other builds of that type that I have seen plans for

[racket]

Yep , Pics over on our sister Site at DIY Gas Turbines
groups.yahoo.com/group/DIYGasTurbines/photos/album/2010994055/pic/list

A very nice build

[sven]

Nice engine, I was thinking about building same style engine, It will be similar but not all same. Right now I'm searching materials,soon as I start building it, I will make a build thread in this forum.
Thanks guys

Sven