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Discussion Starter #1
RB26DETT coolant routing questions.

The basics:
No heater.
Grex remote oil cooler/thermostat plate.

Do 1 and 2 have to be connected if I'm deleting the heater and running a thermostat plate? Is there a way for the coolant from the rear to get to the neck internally? Can 1 and 2 be blocked?



If they must be connected, what is a good size tubing or hose to use?
 

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I'd capp them off no.1 tees off from the water jacket round the cylinders and no.2 it teed onto the inlet to the water pump. Capping them off will increase the flow of coolant round the rest of the system. If there's space on the outlet from the head (top hose) to the radiator, drill and tap it to suit your sensor. It should then be measuring the hottest part of the cooling system, even when the thermostat is closed.
 

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Discussion Starter #4
I'd capp them off no.1 tees off from the water jacket round the cylinders and no.2 it teed onto the inlet to the water pump. Capping them off will increase the flow of coolant round the rest of the system. If there's space on the outlet from the head (top hose) to the radiator, drill and tap it to suit your sensor. It should then be measuring the hottest part of the cooling system, even when the thermostat is closed.
That's what I was thinking as well, but I've been told otherwise.
 

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This is how i have set mine up. Just take the steel pipes out of the block. For the fittings, the one at the back, the thread i think is 3/4" NPT, i just put in a 3/4" NPT to -10an fitting, for the one at the front, you have to tap out the hole to fit an M20x1.5 fitting(it may be M18x1.5 i cant remember, just measure it and if its a 16.5mm hole it will be M18 or if its 18.5mm it will be an M20 hole. For this i use an M20x1.5 to -10an. Then a -10an straight pushlock hose end, some pushlock hose and a -10an 90degree fitting.
 

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This is how i have set mine up. Just take the steel pipes out of the block. For the fittings, the one at the back, the thread i think is 3/4" NPT, i just put in a 3/4" NPT to -10an fitting, for the one at the front, you have to tap out the hole to fit an M20x1.5 fitting(it may be M18x1.5 i cant remember, just measure it and if its a 16.5mm hole it will be M18 or if its 18.5mm it will be an M20 hole. For this i use an M20x1.5 to -10an. Then a -10an straight pushlock hose end, some pushlock hose and a -10an 90degree fitting.
Thanks for help. I was likely going to do a similar arrangement as yours, however I was wondering if it was okay to plug them instead of joining them with a hose. If I was able to go this route, I was considering taping one for a temp sender or using one for coolant to the turbo.
 

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Discussion Starter #8 (Edited)
you can plug them. I plugged the rear and used the one behind the thermostat for my temp sender.

And the rear fitting is 3/4 BSPT. Not very common in the US (and expensive when you find it), I cut down the stock fitting, welded it shut and welded a nut on the end to tighten it. I've heard of people swapping NPT for BSPT and using a lot of silicone or pipe dope, but I didn't feel like risking it, and my way was free.
 

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you can plug them. I plugged the rear and used the one behind the thermostat for my temp sender.

And the rear fitting is 3/4 BSPT. Not very common in the US (and expensive when you find it), I cut down the stock fitting, welded it shut and welded a nut on the end to tighten it. I've heard of people swapping NPT for BSPT and using a lot of silicone or pipe dope, but I didn't feel like risking it, and my way was free.
Thanks man, I was hoping that it could be done. Have you had any problems with this setup so far?
 

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Discussion Starter #10
Thanks man, I was hoping that it could be done. Have you had any problems with this setup so far?

Still building the motor, so I haven't run it first hand, but I know about 3 or 4 others who have, all the hose does is allow water to get from the back of the block to the thermostat quicker which isn't really good or bad, just different water from a different location...
 

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Thought I'd resurrect this as I'm trying to lose all the water pipework from under the plenum. Basically I've no heater or modine so just looking to get rid of a lot of unnecessary pipe/hose.

This seems like a good idea...


but I can't see how you could provide a feed for the turbos unless the left fitting (above the starter) coming out of the rear of the block was a T-Piece effectively sending coolant towards the left of the pic, off to the turbos. When I get home I'll make a drawing of what I'm thinking.

I COULD just keep the pipework and plug up the unused take-offs but I'd much rather get rid (obviously making other arrangements for the vac pipe which is attached!)


TT
 

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Simple drawing showing the basic premise....



Will utilise one of these to screw into the hole at the rear...



and then screw one of these into it..



Will give me a line to return forwards and one to feed turbos.

I think I will give this a try and see what happens...As long as the turbos get a water feed then I cant see how removing all the std garbage can be a bad thing..

TT
 

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The turbo water feed comes from the block on the turbo side.
 

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Excuse my ignorance on your project, I've not read the whole thread.
The feed for both oil and water can be taken from the turbo side of the block as per oem set up.

When I went single turbo, I blocked off most the pipe work under the plenum as I also had a Jun plenum.
 

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Ah, OK. on first glance it appears that the turbo water feed comes from the inlet side and works its way round the back of the block along with the vac pipes.

Unfortunately theres no decent coolant diagram in the wkshp manual.

TT
 

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You're not wrong there, I struggled finding much info but Mark at MGT was kind enough to show me what was needed to be kept or removed.

I will see if I have any pics of what I blocked on the plenum side and what was a feed on the turbo side, hopefully you can make sense of them.
 
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