I'm having an issue trying to work out the heater connections from my CA18 to the original Datto 1200 heater core.

The only half decent picture of the CA18 cooling system I found was on the NICOclub.com Forum and whilst it helped me a little (I think I may be missing a hard line at the rear of the block) it has not resolved anything for me.

At the moment I have two pipes that are about 16mm diameter that have nothing connected to them.
One is a long pipe that runs under the intake manifold toward the firewall.
The second comes out of the rear of the block (just above the gearbox bellhousing) and point toward the drivers side strut tower.

Originally I assumed these two pipes just needed to be hooked up to my heater core. However I am now thinking they are designed to carry the main water flow through the system and I need to be connecting into a smaller bypass type connection.

If anyone has any photos of the rear of their CA showing the connections or can offer any advise it would be greatefully accepted.

Hey Andrew,

Just give me a call and come over, look at mine.
PM'ed my mobile number to you

David

PM replied.

Still keen to hear what others have done. Have you been able to use the original 1200 hoses ( or the same ID hose) to connect up to the CA and where exactly did you plumb it into the CA's cooling system.

I appreciate it's almost impossible to get a decent photo of the back of the motor once it's installed.

All i did was hole saw near/below the other heater hose hole on fire wall on drivers side big enough to put one of those grommets in. Then i ran it as it was in 1200. Passenger side hose long one i ran around back of heater box just enough room and over through the new hole then onto small pipe sticking out of block pointing at drivers side guard. With the original driver side of heater hose on to the pipe pointing at back of fire wall had to use a copper elbow to run the original driver side hose to where i wanted it. Will get pics as best I can over the next few days and outline them with some info and clarify the above. Hope mine are the right way around. Anyway I run it and it doesn't get to hot except when at intersections to long if I don't flick the thermo on but thats more to do with having no fan on the engine.

Thanks for that info DatsAndy. The fact that you could use the original Datsun size heater hose helps confirm my suspicions that I maybe missing a piece or two in the cooling piping. I think from my understanding that you've got them around the right way as far as the water flow goes.......look forward to some pics if you can!

OK, I went to visit Demacoz and had a look at how he has connected his up (thanks David).

He has replaced the hard pipe that runs under the intake manifold with rubber hose and in the process deleted some of the unnecessary cooling paths to the rear of the intake plenum.

As Demacoz is not running a turbo he hasn't had to plumb in the water line to the turbo.

Now whilst I am getting closer to resolving this issue I still have a few things bothering me:

1) The original Datsun heater hose is 1/2 and the Ca18 connections are 5/8 yet no one seems to have mentioned a problem mating the two together?

2) Can anybody categorically confirm which is the preferred connection point from the CA18 to the Datsun heater core for the water to go IN. From what I can find online and using my own questionable logic it seems that the water flow is heading down the hard tube under the intake manifold towards the firewall and this should be the one that feeds water IN to the drivers side of the heater core. This is the side of the heater core that has the tap on it to, so when heater is off you are stopping it before it gets into the core....however a few people I have spoken to have the hard tube connected to the passenger side of the heater core.

3) I have discovered i do not have the factory water line that feeds water into the turbo ( if anybody has one spare let me know) and have been unable to find any diagrams that show this piece. Can someone tell me where this line normally connects into the cooling system and roughly what size the pipe connection is (e.g. 5/8 16mm).

Thanks in anticipation......and Happy New Year to all.