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Howdy,

Have a RB25DET neo with a aftermarket forward inlet manifold an oil cooled turbo, no more oil heater, now running a relocation kit w/ oil cooler.

Need some advice on which holes I need to plug and what I can just block and what should be looped.

Heard someone saying they need a BSP bolt, like the ones found on RB30s.

Any help/pictures much appreciated.

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Sounds like a lot of work for very little gain.

The head ports flow a fair amount of coolant from the back of the head. I have had to make coolant bypass pipes for a few of these Freddy kits now, as they restrict flow back to the radiator.

That doesnt look like a greddy rip off....... not really anyway

The answer to your question is simple. Which ones do you block off? The ones that you arent using anymore. Which for you will be the 2 for the bleed screw and the 1 that goes to the back/behind the block for the turbo water feed if you arent using a water cooled turbo. You can loop the bleed screw ones if you really want but it wont really make a difference

Theres the cheap way to do it, or the neater way to do it. Both work fine, and you don't really see any of this stuff so probably doesnt really matter if you do it the cheap way. This way is to just get the right size hose (you should have plenty if getting rid of the couple of things you will be, or you can match it and buy new stuff) then cut it so you have just enough length to clamp it onto the pipe it comes off then put a bolt or similar in the other end and clamp it tight. Using a bit of loctite 515 or thread sealer helps a bit. Shouldnt matter what kind of bolt you use, and I dont know why someone suggested a bsp bolt, unless they were talking about a BSP plug for the coolant return for the turbo on the other side.

I have a Greddy copy manifold and I have blocked everything I needed to get rid of by brazing bolts etc into the small pipes as necessary. Like I said, both ways work fine, but obviously one looks better, not that you will really be looking there

That manifold is clearly a cut'n'shut using the base of the original manifold, hence why it retains the water pipe underneath. Not that this matters to the discussion at all.

There is no such thing as a BSP bolt anyway, so disregard anything you may have heard about one. BSP mean British Standard Pipe and refers to pipe threads. Bolts come in metric or imperial coarse or fine threads of many different types, but one thing they don't have is pipe threads! You may need a plug with a BSP thread on it to replace a fitting that screws in somewhere and has a hose barb on it perhaps.

The bleeder lines are worth preserving in some way, even if it is just to bring them up to a higher point than the engine at the firewall with something at the top end you can open to let the bubbles out. RBs can be hard enough to bleed up properly as it is without removing the tools that Nissan provided to get the job done.

We moved the bleeder elsewhere, does the job, but not something I would suggest trying to copy with the engine in the car lol

20131120_135043_zpstlb27war.jpg

You can get BSP bolts in a way, if you count banjo bolts. But other then that they are not really something you can just go and buy. I thought when I was talking to a guy I worked with the other day, that he got a BSP left handed tap for a project involving moveable clamps along a bar, but I may have misheard. This was over halfway through shift at about 3am. I'm not usually the most attentive then lol

That manifold is clearly a cut'n'shut using the base of the original manifold, hence why it retains the water pipe underneath. Not that this matters to the discussion at all.

The manifold pictured is a copy of a JUN manifold, not one that has been cut and shut.

I will be installing a greddy copy plenum onto my car and have been wondering about the coolent bleed. Is it really as simple as running a coolant line up as high as possible (above the height of the radiator cap) and putting a screw to bleed it like 89CAL has? That would make life easy :)

Oh, you could turn a piece of rod to the right diameter (same as the outside thread dimension) and then use a die to cut a BSP thread onto the bar....but what you would then have amounts to a plug, which you can buy anyway!

Yeah pretty much haha. Stuff like this would work just fine if it came in the right size

The way we have done the bleeder plug at the back was purely because the engine was out and we had to do something to run the turbo water line around the head drain, which meant we were putting a solid pipe in there. To be perfectly honest, when you get rid of the standard manifold and change it over, the radiator cap is the highest part of the system and I still managed to bleed it without a bleeder screw. But I do agree it is better to have one

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