My car had blowby could it have been because of this?

 

If return line is too small, it can possibly blow a seal in the turbo and will definitly push oil past the seals and make lots of smoke.

 

Blow by is caused by worn or damaged piston rings. Excessive blow by, and by that I mean enough blow by to build pressure in the crankcase, can block the turbo drain line.

 

Depends on what type of turbo your running. Ball bearing turbos require lower oil pressure than journal bearing turbos, so with a ball bearing you can run a very small return line as to a journal bearing you need a larger size return line. Same reason ball bearing turbos can get there oil feed from the stock location on the head, and journal turbos need to get the oil feed from the filter housing!

-nick

 

Oh ran a 62 bb previously and mecanic used same lines