Hi all,

I am fitting an H89 head to an a12. I've looked around, but can't find a drawing showing how the heater hoses are plumbed to inlet manifold. See picture attached showing how I assume it should work. Basically, front of manifold is connected to bottom radiator hose (through a 'Tee' inline with rad hose) and rear of manifold routes directly to fitting in rear of head. I can't imagine this being problematic but keen to hear how it should be.

Cheers.

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  Head to manifold_A.jpg (137.97 KB)


  head 1.jpg (107.75 KB)


  head 2.jpg (116.35 KB)


  head 3.jpg (117.83 KB)

Good question. Yes, that will work for the front

The factory setups (for A14) use a Suction Pipe with two or three outlets



The GX engine uses this one



Water Ports



By the way, the water is not needed, it will run without it. But it helps cool the manifold thus making more power, and it stabilizes the temp for consistent jetting (making more power and economy both)

There is no water connection on the rear of the manifold
* Water enters from the head face water ports
* Water exits into the Suction Pipe
* The rear connector is for manifold vacuum (MANIFOLD CONNECTOR)

Here is the H89 diagram from the Datsun B310 parts catalog

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  B310_C-403_A14-01 Manifold Water Connections.jpg (115.13 KB)


  H89 Head water ports to manifold.jpg (35.04 KB)

Here are the connections for H89 engine (A14 or A15). W75 is late manifold

* The rear vacuum port I believe is for the charcaol canister
* Top vacuum port is for power brakes

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  W75 front connections.jpg (95.66 KB)


  W75 front.jpg (68.10 KB)


  W75 top.jpg (105.08 KB)


  W75 bottom.jpg (116.43 KB)


  W75 right.jpg (91.58 KB)


  W75 left.jpg (91.93 KB)


  W75 back.jpg (98.53 KB)


  W75 port channels.jpg (102.12 KB)


  W75 port.jpg (92.94 KB)

Thanks dd. That is great info. It makes sense that the water will flow from head and then through manifold and into the suction tube/bottom rad hose. It will be less plumbing to tap into only one water port on the manifold too which is great. In my situation, I might actually plumb into the water port at firewall side of manifold as my headers are quite close to the port on front/radiator side.

See picture showing where I will plumb into manifold from bottom radiator hose.

Thanks again dd

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  Manifold rear port.jpg (97.52 KB)

Ah, yeah they're great pics of the manifold too. Sorry, didn't see these before sending last post.

So my plan is possibly to connect the lower rad hose to the 'water temp' port and block off the water outlet passage.