Where exactly to drill drains and pressure holes?

[itoktoeatfish]

any one have a good picture(s) of where to drill/tap the oil return and pressure holes on the head? All the pictures I can find have the lines on already and are hard to tell exactly where they are. Thanks!

[90TurboVan]

Oil drains are to the left and right of the head, just above the exhaust ports. They're drilled through the cross hatched part of the casting. Try and get them as close to the floor of the inside of the head as possible for maximum drainage.

Oil feed is the line that goes into the front driver's side of the head just below the cam sensor. You can pop out the freeze out plug that's in there and tap it for pipe thread. I JB welded an inverted flare to NPT fitting in.

[itoktoeatfish]

thanks! just what i was looking for! By the way, where on the block is your feed coming from? the normal feed for the turbo and pressure guage?

[90TurboVan]

Yes, but I used an oil distribution block from a TII? It had an oil pressure switch, and oil pressure sensor, and the turbo feed (three holes total). I have an oil pressure sending unit on that block, a line going to the turbos, and a line going to the head, which has a pressure sending unit on it after the valve so I can dial in head oil pressure.

[FFWD]

How do you "dial in" head oil pressure? How do you know what it should be? Just make a restrictor like the one in the block. Same size orifice, same oil pressure.

[90TurboVan]

I'm sure the 8 valve head and 16 valve head have completely different flow requierments. I have a pressure sending unit on the head so I can adjust the valve to get the proper oil pressure. I don't remember the number, but I've found suggestions for hot idle oil pressure to the head that seem to work. If you just use the same size restrictor, the head may not get enough oil at high rpms, or it might use too much oil and dry out the bottom end.

[FFWD]

Yeah, the restictor in the neon and TD blocks is the same. The fitting I mounted to the head was welded shut and then drilled to match the restrictor.

[turboking]

I ended up using two feeds to the head (car runs better, no clacking from the lifters) only the sweet pitterpatter of my injectors

[turboking]

WOO

Hold it right there ! I just realized 90 turbvan is running twin turbos on his project. Do tell 90 turbovan!!!!!!!

[90TurboVan]

Finally have some progress

I'll fix the pictures if someone knows how I can edit my old posts.