S1 Radiator Pressure Relief Valve

Barrie Warrener · Posted: Sat Oct 17, 2015 9:55 am Post subject: S1 Radiator Pressure Relief Valve

Can anyone explain the reasoning why this pressure relief valve on a late S1 is used and why it isn't just a simple overflow pipe to stop too much pressure building up?

These are the component parts.

Christopher Carnley · Posted: Sun Oct 18, 2015 9:21 am Post subject:

On standard S1 cars, the steam valve maintains the cooling system at atmospheric pressure. Steam in its various forms as opposed to hot water.
Cars with the R-R Internal Cooling system Aka, Air-Con, which this car ain't not got (DG) have a radiator pressure maintained at 7 lbsqin.
Some of the R-R conservative thought processes were abandoned only slowly, unless the Americans came up with good ideas.

Barrie Warrener · Posted: Sun Oct 18, 2015 11:35 pm Post subject:

Thanks Chris but I'm still not sure what it does.....

I wonder why they didn't just have a vent which would have also served as an overflow for excess water?
I really can't see what the valve does

Christopher Carnley · Posted: Mon Oct 19, 2015 8:01 am Post subject:

It prevents self-syphoning.

Robert Craven · Posted: Mon Oct 19, 2015 8:01 am Post subject:

Where does the black pipe at the side of the valve lead to? Is it to an overflow / recuperating bottle like some other cars have?

Barrie Warrener · Posted: Mon Oct 19, 2015 8:58 am Post subject: