The V8 Owners Forum -

Hi fellas, I am putting a discovery 3.9 EFI into my MGB. I will be converting the engine from Serpentine to the older SD1 timing cover. Just thinking about the layout of the hoses. My engine's in the shed and I haven't seen it for a while as it's buried under shed crap. I have the two hard lines that run down the side of the plenum with the air bleed at the top. I'm a bit of a Newby to all this.I would like to check my understanding.

Cooling
- Hot water enters the top of the radiator coming from the manifold and cooled water comes out the bottom. I'll be putting an inline thermo in that.
- Cooled water enters the engine via the water pump.
I have Clive Wheatley hoses for this.

Heating
- Hot water is pumped from the manifold to the heater via the control valve and then to the water pump.
I'll attach a universal heater control valve on the end of the hard pipe and then into the heater. I need to attach the return from the heater to the SD1 water pump.

As I understand it I'll need:
- A suitable spigot for the Thermo Housing
- hoses for the heating pipes. Anyone know the size of the heater hoses and who sells preformed bends?

Thanks for your help.

There are a few variations of the heater / thermostat bypass circuit.
Hot water enters the inlet manifold at the rear from the heads. From here it can either exit rearwards to the heater (which returns to either the pump or bottom hose). Alternatively it can run forwards through the manifold to either the thermostat and on to the top of the radiator, or through the thermostat bypass hose to the back of the water pump.

Depending on the front over etc, your water pump might have 1 or 2 inlets for heater hose / thermostat bypass. I have also seen the casting with one of them blanked off, so the existence of a spigot does not necessarily mean that water can go in that way!

One of the two circuits must be open at all times, so it's worth being sure exactly what you have.

I got pre-formed bends from Car Builder Solutions.

Chris.

Thanks Chris