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Glad the above info was helpful.

Quote:
Originally Posted by klefroid View Post
I'm a bit concerned about that oil cooling thing.
A Garrett needs a oil restrictor so that turbo has to cool down by that tiny hole?
What if that restrictor gets blocked by something in the oil line?
This would mean that the turbo get's seriously damaged?

Ahh, the old scare about oil and cooling...

3LDZ and K-series turbochargers have a lot less oil flow through them than comparably sized journal bearing turbochargers, ex. T3 and T4. Should we worry about the longevity of a K27 because of this? No, of course not.

Yes, the Garrett ball bearing turbochargers require a very little bit of oil flow. Shockingly little in comparison to the K-series or the full-flow T3 and T4 turbos.
All BB turbos (that I know of) use very little oil. BW EFR turbos are restricted, Turbonetics, Precision, etc.
Worrying about their oil demands is pointless.
Their reliability is proven, from street cars to LeMans, piston and rotary engines. We don't see failures related to overheating, and our summer time temperatures routinely exceed 110F (43F). Our Middle East customers don't kill them nearly as quickly as they destroyed 3K and Holset journal bearing turbochargers. We have many customers in hot equatorial regions, been using the BB turbos successfully on 911 Turbos for many, many years.


As for blocking the oil hole: restrict ANY turbocharger's oil flow more than it is designed to be limited, and you'll accelerate the turbocharger's failure. Look at a turbocharger's bearings, and you'll see the oil holes are about the size of a needle. Block one and it's usually game over for the journal bearing.
But a more important question should be: why would you have such large debris in your oil, anyway?
If you have debris large enough to block the oil restrictor, you aren't worried about the turbocharger anymore... because something that big just damaged your engine oil pump.


Concerning turbocharger cooling, that has been discussed on this forum ad nauseum. In short, hot shut-offs coke up oil and lead to the failure of any type of turbocharger, ball bearing or journal bearing. A cooling system provides almost no turbocharger cooling while the engine is running, but help prevent heat soak and coking after shut off. Air-cooled 911 Turbos don't have a cooling system. That's why the K27s used on 911 Turbos are specified with a "dry" bearing housing, not the version with a cooling jacket. Garrett was a little smarter, and doesn't cast 2 versions of every bearing housing, one with a cooling jacket and one without.


But other good turbos you can use as well:
S200 or S300 series turbochargers
Holset -- though the ones we have experience with aren't suitable for a simple 7:1 3.3L
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Old 04-30-2014, 04:48 PM
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