Oil Drain Line Question and Help

[88turbobird]

I’m having some issues with my new BB GT35 turbo smoking after sitting at idle. I don’t believe my drain line (currently 5/8”) is kinked but I’m not 100% given how tight the radius is. I was thinking of increasing the actually line size to 3/4”. Right now, the fitting off the turbo is 10an so I was thinking 10an to 12an line into the block. My only concern is that the fitting going into the block is 1/2 npt. Is the 12an to 1/2npt too big of a reduction? Any suggestions would be appreciated.

[Stinger]

You're likely better off going to the pan if you think the drain needs more flow. That way you can use larger fittings all the way and also have more drop so gravity will pull the oil to the pan.