OT Ricer turbo question

[Mac]

My son is putting together a turbo Honda Civic and just like his old man he's using scrounged up components.
The turbo unit came from one source along with the oil pan. The PO has a 5/8" nipple off the turbo and into the pan for oil return with what looks like heater hose between (yeah, the rubber is swelling).
The question is: No doubt it need changing but am I correct in advising him to adapt it to AN6 or even AN4 line because as well as being unsightly it's excessively oversized for oil return?

[unklian]

"Too big" on an oil return isn't a problem;
the return is always bigger than the feed line.

[Leon]

I'd use a AN10 to AN12 for the return.

[Mac]

"Too big" on an oil return isn't a problem;
the return is always bigger than the feed line.

My thinking was that with a big hemoraging return line overall oil pressure could drop. Also, with the oil "dwelling" less in the turbo it wouldn't cool as well, like can happen with a water pump??

[enjenjo]

"Too big" on an oil return isn't a problem;
the return is always bigger than the feed line.

My thinking was that with a big hemoraging return line overall oil pressure could drop. Also, with the oil "dwelling" less in the turbo it wouldn't cool as well, like can happen with a water pump??

nope. The bearing clearances control the oil flow. And the more oil that flows, the more heat it removes.

On a water pump, it can't flow too much, unless it is creating a negative pressure, causing the coolant to boil at a lower temperature. A water pump can't pump vapor. Short of that, the more coolant flow, the more heat removed.

[Mac]

On a water pump, it can't flow too much, unless it is creating a negative pressure, causing the coolant to boil at a lower temperature. A water pump can't pump vapor. Short of that, the more coolant flow, the more heat removed.

Where did I read that a hi-perf water pump was not good for the street because it moved the coolant thru the radiator too fast to give up heat?
Yet again my sig. proves apropo.  :oops:

[enjenjo]

On a water pump, it can't flow too much, unless it is creating a negative pressure, causing the coolant to boil at a lower temperature. A water pump can't pump vapor. Short of that, the more coolant flow, the more heat removed.

Where did I read that a hi-perf water pump was not good for the street because it moved the coolant thru the radiator too fast to give up heat?
Yet again my sig. proves apropo.  :oops:

You might very well have read that, but it's not true. The speed the coolant moves through the system is irrelevent. The amount of the coolant that is exposed to the air flow is more important. If you can disrupt the flow to make the coolant swirl and tumble in the tubes, it will cool better

[Mac]

Thanks, everyone.

[Bruce Dorsi]

The 5/8" size is correct for the turbo drain.

If he doesn't want to use braided hose, regular hydraulic hose is rated for hot oil, and will not swell.  ......Fabric-reinforced hose is more pliable and easier to work with than wire-reinforced hose.

The drain line is not under pressure.  ......That is part of the reason that the drain hose needs to be larger than the pressurized supply line.