You are correct/

Usea small punch thn work your way bigger till a thread ca be tapped with grease on tap to hold any brocken threads.. Then screw a fitting in tap wit some sealant...Pipe should be atleast 15mm...As said in this Vortec guide...
http://www.vortechsuperchargers.com/pdf ... A218IM.PDF

How thick is the sump? I wouldnt have thought it would be thick enough to tap a thread into it?

Vortech knowbetter than I do...
You need a prick punch first or drill small hole to start. The return hole is close to top of sump and should be beside main bearing cap if you can...
As said in Vortech link above.. For V8 but much the same....

ive got a large punch with a long bar welded to it. I can put the punch in the desired location, the bar will extend out from the side of the front of the car (in front of the drivers side wheel with the wheel off) and can easily smash the end of the bar to make a hole in the side of the sump (about 1" from the matting surface of block/sump) to suit the tube I want (16mm to 18mm).

I made up a 16mm pipe bender so that I can bend the tube into whatever shape I want for both the sump and the turbo. I think it really needs 18mm tube


For the sump: there is not enough room to do a proper weld. Screwing it on wont work very well so I did the following.

I tack welded it on with the mig (which I dont think is necessary to do), but then I GLUED the pipe on sump.

You use the CARGO brand putty for fuel tanks. Its resistant to oils and works the best IMO untill the engine comes out and you weld it properly.

You push the pipe into a tight fitting hole (done that a few time) and you use the kneaded putty and push a whole pile of it around the tube and sump. Make sure you clean the surfaces so theres no paint or oil. You can even roughen the surfaces with sandpaper before you punch the hole.

Never failed for me

Hope this helps

I drilled it with a gob of vasaline on the drill bit... pulled it out and all the shavings were stuck to it, then I just changed the oil and filter a few times with cheap oil to flush it out.

I tapered the hole so I could get a thread on it but I over tightened the brass fitting so it wasnt tight enough... I ended up putting metal putty around it and it dried like cement and never ever leaked.