Originally Posted by Mike Rainbird

Just to make you aware that the pump pictured is actually better MADE than the OE pump, as it is machined from a billet rather than cast. Therefore the tolerances are a LOT better than the original cast ones and they don't have the same high temperature expansion issues (which causes a drop in pressure on the original pumps at high oil temps). This means that the new ones have more consistent oil pressures and give an increase in pressure purely from their better tolerances.

HOWEVER, it looks as though there is a design flaw in the machining work that means that the casing is not rigid enough to take the increased pressure?

I have sent this link to Jeremy at Cosworth in the hope that they can get the design updated or to see if it is a one-off that got over-machined in a critical strength area?