Alibaba 70mm Turbine Clearance

[shanaka]

Guys,



I recently busted my 70mm turbine (purchased) and the NGV (homemade). I purchased both the turbine and the NGV from Alibaba.com to replace them. My previous turbine / NGV clearance was 0.1mm. However the NGV and the turbine I received from Alibaba.com today has a clearance about 2.5mm. (70mm turbine and 70.5mm NGV). From my experience I know if the clearance between the compressor and its housing is critical and should be less than 0.1mm. Will this be a problem?



Cheers,



Shanaka

[racket]

Hi Shanaka

0.25mm radial clearance should be just fine to use , a 70mm dia turbine wheel will expand by ~0.7mm when running , compressor wheels by comparison will only be a fraction of that , your previous 0.1mm was probably a tad too close a fit.

Cheers
John

[shanaka]

Hi John,

Thanks for the reply. Then it's good news! In that case, I should be back in business with a few mods to the parts to match the new NGV. And, yes, I think you are correct about the previous clearances. I was a bit worried about the tolerances before and bored the NGV, gradually till it doesn't touch the wall anymore when I idle the engine. So the gap was not quite wide enough.

Cheers,
Shanaka