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Rb30 With Rb25 Head, What's This T-piece?!

Blipman
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Blipman Enthusiast

Blipman

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I'm currently swapping an already built and previously installed RB30 with RB25 head engine into my R33, there is a T-piece on the RB30 engine near the turbo oil return line that isn't on my original RB25 block, what is it for? See pics

This is the T'd piece on the RB30 block

oil-t1.jpg

More pics, it's at the bottom and slightly to the rear of centre

oil-t2.jpg

oil-t3.jpg

And this is the same point on the oroginal RB25 block, no T-piece

oil-t4.jpg

What is this for?

In this particularly well written article about RB30 conversion here: http://www.skylinesaustralia.com/forums/post-a132205-

it says "The R33 RB25 also requires you to plumb in an external head oil return, you can T in to the turbo drain" which sounds like what was done with the RB30 engine I have, but I can't for the life of me work out where this T-piece is supposed to plumb into on the head! Any ideas?

Ben

Blipman Enthusiast

Blipman

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Posted (edited)
drill and thread it into the back of the head

But this head and this block were already mated together and in a car previously. If this step had to be done it would have been already, yet there's nothing I can see in the back of the head that has been changed or anything tapped in there..

More confusing, it looks like my head HAS been modified to allow oil to the VTC, you can see the braided line here which supplies oil since the RB30 block doesn't have this. So the oil is getting in, how the hell is it then getting out?

vtc-supply.jpg

Everything points to the conversion being done properly and the engine I've got is complete, but still that T-piece on the turbo return line has me stumped.

Ben

Edited by Blipman

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