I'm fitting my cooling system on my haynes roadster using the donor Sierra engine (1.8 CVH) and most other parts. Ifound a used clio radiator and have made the brackets to fit it in place. Now I wonder if I've fitted it upside down! The clio radiator has large (32mm) inflow and out flow pipes and a smaller pipe, which on my current layout is at the top of the radiator.

I think I have worked out the circuit used on the Sierra: cold water from radiator bottom hose flows into engine water pump and up through engine and out into channel in the inlet manifold. Thermostat prevents water going out to radiator top hose until water is heated up, so it flows to automatic choke and then to heater, returning back to join water pump at base of engine. I will miss out heater and just return this back to water pump direct. When water heated up thermostat allows water to pass from inlet manifold channel into radiator top hose and back to water pump at base of engine.

There is a pressurised expansion tank which receives water from the thermostat housing and returns it to the lower small pipe on the radiator.In the Sierra this return is to the bottom of the radiator and is presumably gravity fed.

The way I have my Clio radiator fitted this return pipe is at the top, so it will be difficult to get the expansion tank high enough to creates a good gravity feed.

Have I got to turn the radiator the opposite way up, so this pipe is at the bottom and remake brackets etc. or is there another solution. Or have I got it all wrong!

Guidance from the experts gratefully recieved.

Thanks

Pretty sure the small pipe on top of rad is a return/bleed that usaully returns into the top of the header tank.

I would 'T' your feed from bottom of header tank into your bottom hose to rad, and leave the rad the correct way up, then 'T' your top small bleed pipe from rad into your top pipe onto header tank.
The bleed pipe on rad makes bleeding the coolant system alot easier.

[Edited on 16/7/14 by CosKev3]

Thanks very much. We have designed it with your suggested layout and will fit tomorrow. Engine a way off running so we will have to wait and se how it all goes.