CB350 tranny + Yanmar L100 + Turbo

Doing stuff with air...

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andrewaust
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Re: CB350 tranny + Yanmar L100 + Turbo

Post by andrewaust » Wed Dec 16, 2009 4:20 am

This is the culprit why the turbo bearings failed, restricted oil supply to the plain journal bearings Image

My previous post explained journal bearings in turbos need to be pressurised not just lubricated. Ball bearing turbo chargers can have a restricted jet placed into the system to stop oil seeping from the turbo core and also can prevent the starvation of oil pressure in some engines which have a rather poor oil system.

Yes the L100 clone engines do have an oil pump toyotaracer9, it's also interesting to note it has no relief valve in it's system, talking to a Yanmar dealer stated on startup there original L100's can get 100psi which is rather high, would be interesting to know what pressures you would achieve when the engine is hot and a turbo which has no restricted oil line would have.

The reason journal bearing turbo charges need oil pressure is the same as mains and big end bearings in the engine, to keep the metal parts from contacting each other, no pressure and your in for an expensive repair bill.

If the turbo isn't to badly damaged mazdog you might be able to go onto ebay and grab a bearing kit, not sure of price but have seen them. Although just keeping it self aspirated will extend engine life and be less of a hassle. My turbo is still sitting on the shelf ;). My reason for not installing has to do with snapping the Enfield gearbox input shaft, so more power would certainly stuff another one.




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andrewaust
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Re: CB350 tranny + Yanmar L100 + Turbo

Post by andrewaust » Wed Dec 16, 2009 4:23 am

A good read for those interested in journal bearing turbos http://www.berrimadiesel.com.au/publica ... Basics.pdf


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