Turbo Oil Drain

[unlimitedpower]

Well its getting very close to the time when im going to have to get off my arse strip my L18E and put it back together with new rings bearings valve guide seals etc. (mainly i just don't want the bastard to leak on my new paint).

Well what i was thinking while its al apart and i have to move the dip stick to the rear hole as im changing sumps maybe i should drill and tap the front hole (existing dip stick hole) for a oil return.
I don't really have any plans of turboing the motor but things like that have been known to change as years go by.

So what i was wondering is if someone can recommend if.

A: Is it a good idea
B: What size thread should i get it tapped to??? (i'll just put a bolt in it when its not in use).

Thanks
Brett

[Bartman]

I wouldn't advise that. Oil returns need to be of a pretty decent size, and I don't think it'd be prudent to drill a hole that big in your block. I don't imagine it'd do the strength of the block any good. (After all, iron is pretty soft really)

[unlimitedpower]

Fair call it was just an idea i came up with.
That will save me some time and effort.

[85_Z31]

Ok so an oil return for a turbo is pretty simple but there are a few things that need to be done a particular way.

1) It needs to be a decent size the oil return on my VG30ET sump is 18mm OD and about 17.5mm ID

2) Oil return needs to be above oil level in the sump so that the oil supply doesn't back up into the turbo and blow the seals.

3) the stub of pipe that sticks out needs to be a decent enough length like 35mm so you can get a decent hose clamp on it.

as a bit of a note if the turbo is a low mount the oil can't be forced to go back up hill or the scenario from note 2 might happen and cost you a turbo. So sometimes it can be tricky getting the oil return high enough to be above the oil level in the engine and low enough that oil flows to it from the turbo freely.

Hope this helps - take a look at this pic to see what i mean about placement