The V8 Owners Forum -

Hi Chodjinn,

My inlet manifold doesn't appear to have a connection anywhere on it for a breather to be connected, I am a little reluctant to drill and tap it for this purpose, if I have to then I will.

I have a pressure cap on top of the expansion vessel, the expansion vessel is the original 1978 MGB brass tank that was fitted to the 1800 engine.

I am wondering about fitting a header tank rather than this expansion vessel!

What about the bleed from the heater return you mentioned? Not ideal though. Strange your inlet manifold doesn't have one, are they all like that?

My pressure cap was on top of the header tank, as my radiator was sealed. A header tank would definitely be a better choice mate, as connecting any breather/overflow to the top means that entrained air can vent their without issues. With an expansion tank, being the fill point as well such as in your application, it would have to push against flow, and air doesn't like doing that much.

You could try it pretty easy, go to a scrappies and pick up a modern header tank from pretty much any car.

Hi again guys,

Just a quick one as I got a few minutes to have a look over the cooling pipework again today.

Should the feed from the heater matrix go in to the upper or lower inlet point? And the feed comes from the rear of the inlet manifold correct? Then returns along the rigid pipe in to the suction side of the pump.

Many thanks again.