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Rb25 Head Vct Modifications...

MBS206

By MBS206,
in Engines & Forced Induction

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MBS206 Grand Master

MBS206

Posted
Posted

Hey guys,

I've been searching and digging around for some info, but I can't really find what i need...

Anyway, I have an RB25DE head from an R33 (YES it HAS VCT!)

Now, I had a workshop do the tapping of the hole for the oil feed to the VCT...

Now my issue seems to be, he's tapped the hole on the SIDE of the head...

IE, pretend you're bolting on the inlet plenum, the way that bolt is being done up to bolt it to the head, is the same way you would do up the oil fitting to the head...

As in, the hole is on the side, not the front...

Now, why such an issue I hear you all ask... Well issue is, when I have the little adapter, plus the oil line bolted onto it, it fouls on the water feed into the plenum.

As in, the actual fittings JUST clear it, but the alloy oil line fouls it, no matter how hard you turn it, as the fittings JUST clear (As in, half a millimetre)

So I went back to my local place for getting bits and pieces like this, after a bit of chatting, instead of running a straight adapter out of the head, I got a 90 degree bend so I could clear everything...

ISSUE! This fitting cant be screwed in, as it fouls on the head as you turn it to screw it in (Where the stud goes through, it hits this bulge)

So, I'm wondering, how have others done their oil fittings if their hole is tapped in the same spot.

OR, if I plug this hole, and DON'T feed my VCT any oil at all, what issues can I encounter? Should I pull the VCT valve out and just put a plug in here too? Or would I be better off getting a fitting that will fit the VCT hole, plugging the one I tapped and just feeding constant oil up there. (I don't care right now if VCT does, or doesn't work)

I don't have the cash to change cams, hence, not worried right now if I lose VCT, so long as i don't smash a motor to pieces...

Any help...

Thanks

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https://www.sau.com.au/forums/topic/257996-rb25-head-vct-modifications/
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MBS206 Grand Master

MBS206

Posted
  • Author
Posted

Hey man,

I can't exactly go drilling and tapping shit at the moment, as the head has already been service, cleaned and rebolted to the motor.

I'm at the part of needing to get this oil line done, so I can put my inlet plenum back on...

Adriano Grand Master

Adriano

Posted
Posted

You may not have any other option. Can you gat a 45deg fitting instead of the 90 deg one you bought, it may be able to be screwed in and clear the inlet manifold. Has the workshop offered any advice as to why they did it this way instead of the way everyone else does it?

psi Experienced

psi

Posted
Posted

I drilled into the end of the bush which faces the front of the car. This means that no fileings goes in side the engine.

all you have to do is pull the plug out. modify it and push it back in. job done

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