What have you done today with your Austin Seven

[Chris KC]

I once aborted an intended overseas jaunt at Southampton when the oil pressure dropped to zero (normally a healthy 35 - 40 psi at least). When stripped down I found a flake of old red hermetite in the oilway completely blocking the entrance to the oil pressure gauge pipe.

[Ruairidh Dunford]

It’s not a trade secret.

1. It will take me ages to write it down.

2. I cannot be bothered with the potential teeth sucking that will ensue, if you are a reasonable person I am sure you will relate..

If you want to know, phone me and I will happily describe how I have done it previously.

[Colin Wilks]

Don't worry about it Ruairidh. Just idle curiosity on my part. Thanks for the excellent job you did on my sports crankcase.

[Ruairidh Dunford]

Any time Colin.

[Parazine]

I had an oil pump gear key shear once, that resulted in zero pressure.  

That was on a standard pump.

It is possible to remove the pump without removing the block and the engine from the car, phone me if you would like to know more on that.

This happened to me as well, back in the seventies, with my first Ruby. I was on my way to work at 07:15 when the oil pressure went to zero. I continued for another 4 miles with zero oil pressure and got into work on time! 
A friend towed me back home, where I found that a big end split pin had broken up and a piece of it was jammed in the oil pump, seizing the pump solid and breaking the drive taper and key.
Since then, if I use split pins on the big ends (I prefer Nyloc nuts now) they only get used ONCE!

[Charles P]

Well my diagnosis was correct so I have a complete strip down to solve the problem. I'm going to lap the gear onto the taper and fit the key with the same love and attention that I apply to half shafts. It really is a bloody awkward place for a tuppenny component to fail.
Oddly I'd never heard of this problem until it occurred to me!

Charles

["Slack Alice" Simon]

I have recently driven a car with the gauge on zero when running between 30 and 40 mph.

Revving produced a flicker off the stop, from cold it was up to (say - I can't really remember) 10, falling to zero after warming up.

I advised the owner to try swapping gauges, but could it possibly be a sheared key and slipping gear?

I think I would expect more inconsistency if that was the case, but I don't like driving with zero or near zero showing.

Your experiences, please.....

[Alan]

It depends. I imagine Charles’s is a pressure fed engine. In which case zero is definitely wrong. A splash fed engine might well show zero on the gauge when fully warmed. Depends on the gauge.

[Ruairidh Dunford]

I agree - our RK sits on zero at 45mph when fully warmed up, always has.

[David Stepney]

My RP runs between 2 and 4 lbs/sq. in at 30 mph hot, but sinks to zero at tickover. I have to tap the gauge to get it to register again! When cold, the needle leaps to the top of the gauge.