Blanking Off Heater Connections in a RRC

[Davo]

Now, I do realise this has been covered and I did do my forum duty by searching first, but I just wanted to double-check on this one.

On a Rangie carby engine, there are two inlets in the timing cover behind the water pump. The RH inlet, (looking from the driver's seat, naturally), goes to a steel pipe that runs underneath the inlet manifold. The LH inlet goes to a steel pipe that is cast into the inlet manifold. The other end of this pipe is open inside the inlet manifold - this can be seen when looking through the back of the inlet manifold with the heater feed pipe removed, (the one that's attached to a plate that bolts onto the back of the manifold).

While working on this cooling system to replace all of the hoses it has occurred to me that I don't want the heater in the system at all. This is because we live in one of the hottest parts of Australia and will never use it, but also because I've read about the heater core leaking coolant into the inside of the car and since we're in a remote area this would be a bit annoying, fixing it on the side of the road with Toyotas whizzing past and all.

I've also figured out that the coolant flow goes from the water pump through the two cylinder banks, through the heads, and then through the inlet manifold to the radiator. This means that the heater is fed from the heater feed pipe at the back of the manifold, and the return from the heater is through the steel pipe under the manifold and then to the RH inlet at the back of the timing cover.

Also, the coolant bypass is through the steel pipe, (the one cast into the manifold), and to the LH inlet at the back of the timing cover.

Soooo . . . it should be okay to put a flat plate at the back of the inlet manifold where the heater feed pipe was, put the usual short hose to connect the bypass pipe from the manifold to the LH inlet, block off the RH inlet, and just ignore the steel pipe that runs under the inlet manifold.

I know I could just use a U-shaped bypass at the back of the inlet manifold but what I'm thinking of not only removes a few extra potential leaks but also avoids some rusty bits!

Apologies for the long post - and a big thanks just for reading this far!

[ChrisJC]

Yes. The two pipes in the back of the water pump are thermostat bypass (you need), and heater return (you don't need).

So blank off at will.

Chris.

[DaveEFI]

The steel pipe which runs under the inlet manifold and screws into it is a far more likely cause of a leak than the heater itself.

On an SD1 with aircon, there is a shut-off valve on the other heater pipe - so given air con is likely to be used under the hottest conditions, the water flow through the heater has no effect on the engine cooling system, I'd say.

[Davo]

Ta very much for that. I didn't think of that steel pipe as being such a problem but sure enough, it's a rusty mess.

Thanks again!

[DaveEFI]

Ta very much for that. I didn't think of that steel pipe as being such a problem but sure enough, it's a rusty mess.

Thanks again!

At one time they were NLA, and I made a new one using domestic plumbing bits.