First Turbine - M24 Garrett A/R 70

[Colin Heath]

Hello All,

I managed to get a turbo charger from a performance car company I do a little work for to use as my first learning project.

All I know so far is the M24 and A/R .70 as that is what's stamped on body. I have included some pictures. I have lots to learn but first will need to identify turbo so I can get appropriate data sheet to size everything else.

There is a decent amount of play both radial and axial (end float) but the unit was from running vehicle. I don't know if it's worth rebuilding or if the torture I will put through as a beginner make that a waste of time?

The fabrication of parts will be the most straight forward part for me it's more about the sizing of combustion chamber, layout of holes in flame tube, what shape holes work best as I can CNC plasma them so don't have to be round and many other things.

Looking forward to getting started.

[Colin Heath]

I am looking at combustion chamber design and from reading it seems 2 x inducer diameter would be my target, is that correct?

My main concern is if the combustion chamber should be coned down into turbine inlet (Mine is rectangle inlet) or would a flange in a flat chamber end work? I'm assuming coned from round to square would be better due to improving the flow?

My long term aim is to now mount this onto my lawn mower / tractor and thinking a second turbine stage for driven power would be much more efficient? Also the current gearbox on the lawn mower sits horizontal so lends itself perfectly to an upright shaft from a turbine mounted up-turned 90 deg exhaust. This could also be front mounted.

[racket]

Hi

You'll need to measure both wheel sizes first , this will give you an indication of its potential as well as the sizing of the combustion parts .

Yes, we need a smooth transition from the flametube cross section into the turbine scroll mouth

Cheers
John

[turboron]

cph007, your turbo appears to be a one of the larger frame Garrett turbochargers. There is usually a nameplate with the part number on the backside of the compressor scroll. The part number form is xxxx-xxxx.
If you find the part number you can get a lot of information about the unit on www.turbomaster.com.

Thanks, Ron

[Colin Heath]

Jan 8, 2020 16:01:49 GMT -5 racket said:

Hi

You'll need to measure both wheel sizes first , this will give you an indication of its potential as well as the sizing of the combustion parts .

Yes, we need a smooth transition from the flametube cross section into the turbine scroll mouth

Cheers
John

Not sure what I have done with the quoting here but called somebody else john and twice!

I will measure up and see what I have and how useful. Thanks for reply

[Colin Heath]

Jan 8, 2020 16:36:09 GMT -5 turboron said:

cph007, your turbo appears to be a one of the larger frame Garrett turbochargers. There is usually a nameplate with the part number on the backside of the compressor scroll. The part number form is xxxx-xxxx.
If you find the part number you can get a lot of information about the unit on www.turbomaster.com.

Thanks, Ron

Thanks Ron, the numbers I have are stamped on the casing but will have a good dig around tomorrow after a clean.

[Colin Heath]

I have stripped the Turbo today to take measurements and got carried away, the turbo is now useless as the balls fell out of the bearings!

I spoke to garrett but they can't identify the unit from the numbers stamped on it so not sure how I am going to get a new cartridge or bearings. I'm hoping some measurements will tell them all they need to know.

Here are specs of unit:

- Inducer 56mm Exducer 76mm (Edited as I realised I didn't even know what inducer and exducer were!
- Turbine = 55mm exposed diameter

So if I can get this thing rebuilt then I'm thinking that it's 100mm dimeter flame tube and 130mm combustion chamber although I have 154mm tube here already but maybe too large?

Here are  few more pictures of the unit:

[miuge]

It seems to be some sort of T3/T4 hybrid based on wheel sizes, but a ball bearing version?? Not the best candidate turbine exducer being smaller than compressor inducer, also rebuild can become expensive or hard to find parts if it's really a BB chra.

[Colin Heath]

Jan 9, 2020 14:19:08 GMT -5 miuge said:

It seems to be some sort of T3/T4 hybrid based on wheel sizes, but a ball bearing version?? Not the best candidate turbine exducer being smaller than compressor inducer, also rebuild can become expensive or hard to find parts if it's really a BB chra.

Thanks for the info. I wonder if this is a fake/copy as garrett didn't recognise any numbers and they were stamped, not on a plate as theres are.

Seems to definitely be a GT35 and can find a cheap copy with same .7 / .82 AR. It has BB CHRA.

With this in mind I may just buy a chinese turbine with better specs to suit what is needed and chalk the other one up to experience! 

[slittlewing]

Hi Colin,

I would recommend checking out prices on AliExpress, particularly for copy holsets. Depending whether you are thinking of installing your engine into a vehicle or not (and the fuel consumption), it’s almost the bigger the better. You can pick up hx50, hx55 or hx60 turbos on there all for very little!

Looks like your Garrett was from a petrol engine. Diesel turbos have correct sizing for our engines.

Cheers
Scott

[Colin Heath]

Jan 9, 2020 15:42:05 GMT -5 slittlewing said:

Hi Colin,

I would recommend checking out prices on AliExpress, particularly for copy holsets. Depending whether you are thinking of installing your engine into a vehicle or not (and the fuel consumption), it’s almost the bigger the better. You can pick up hx50, hx55 or hx60 turbos on there all for very little!

Looks like your Garrett was from a petrol engine. Diesel turbos have correct sizing for our engines.

Cheers
Scott

Cheers Scott,

I was about to ask what a good turbo application would likely have right compressor inducer to turbine exducer ratio (now I know what they are) but you have saved me the trouble, so thanks

I will go take a look and see whats about as rebuild will be just as expensive as new

[racket]

LOL...........why settle for a "small" HX , look at the Chinese HX82 and older HC5A units , theres some 100 mm inducered ones , but finding the right one will present difficulties

Cheers
John

[Colin Heath]

Thanks for the help so far everyone. I am ditching the old turbo as not the best anyway so not much point in throwing money at it.

I have gone for a chinese turbo copy of GT45 as it has larger turbine exducer than compressor inducer and should be a good start point. it is also without water cooling and plain bearings so better suited for what I am planning.

I think maybe start a new thread once I have some more details.

[Colin Heath]

Jan 9, 2020 16:41:55 GMT -5 racket said:

LOL...........why settle for a "small" HX , look at the Chinese HX82 and older HC5A units , theres some 100 mm inducered ones , but finding the right one will present difficulties

Cheers
John

Those huge units look like good fun but may stretch the budget for my first build as I'm pretty sure I'll end up destroying this one, I mean stress testing it!

[miuge]

Search for "HC5A 3594143 3594144 3594199" on Aliexpress $356 + shipping.
Make sure the turbo has single entry turbine housing, those GT45s are usually twin entry, not ideal for DIY turbines.