Hi Anthony

The high flow MG B oil pump is producing high pressure, 90 PSI is very high and will blow past the scroll seal on the back end of the crankshaft, this was designed for a much lower pressure,and to some extent a lower flow.

High flow oil pumps are designed to remove heat from the bearings at high engine speeds, because the high flow of oil is trying to get down a hole that is designed for a lower flow, the pressure will rise significantly, the pump is a positive displacement type so doses not allow "slippage" of the oil in the pump, this could cause serious damage by actually generating heat due to the increase in pressure.

I would recommend either using a standard oil pump or use a shorter spring in the oil pressure relief valve may help.

You clearly have your reasons for the upgrade of the oil pump.

Kind regards
Trevor Jones

Hi every one.
I need some help with a problem on the car. I have a 3 bearing ZA and the gaskets around the sump leaks oil when the engine is running. It runs down the back plate between the sump and the plate. No oil comes out of the small drian hole in the gear box though. When the engine stops so does the oil. I tryed changing the gaskets and putting "well seal" on it but this has not worked. The oil pump is a high flow unit for a MGB, and I get about 90 PSI on the gauge when running and about 75 When ticking over. has any one had this problem with the high flow rate pumps.

any help most greatfull.
Anthony