SKCC - Southern Kit Car Club. A Club for kit car owners across Southern England. Kent, Sussex, East Hants, Surrey, Berks, Middlesex, London

Been thinking about potential solutions to protect the engine in the event of low/loss of oil pressure...

Currently on my car I have an oil pressure sensor wired to a mechanism for cutting the fuel pump when there's insufficient pressure. My assumption is this is a carb-only solution though as you can start the car on primed carbs without the pump running, i.e. before oil pressure has been attained. As I'm converting to EFI I need a different solution.

Some current ideas include:

• Extend the previous solution with an Accusump to provide pressure before the engine is started.
• Install a massive f*** off warning light to alert the driver to low pressure.
• Doing something at the ECU to cut the fuel pump at low pressure after starting.

Discuss...

I think tones light is enough but a (loud ) buzzer wired to it would be good

A big red warning light always worked for me. Knocked the pump feed off the Fiat twin cam twice and the engine was not damaged in both cases.

You cant beat a large light near your line of vison. never had a problem with this method of dealing with low oil pressure.

Going back to basics (Dick will correct me if I'm wrong) the engine won't die as a result of no oil pressure. It dies because without pressure the oil in the bearings is not replaced & overheats, the bearings overheat & the engine seizes, so the time you have is measured in tens of seconds.

The normal oil pressure light switch fires at 5psi, so only lights when you REALLY have a problem. I fitted one that lights below 25psi. I had an oil leak a while back & noticed the oil light flickering under acceleration, so I stopped & found the problem before it became serious, but there was no damage to the engine from the short term lack of pressure

I've got 21psi light switch too.

I'm not keen on low pressure cutting the engine with no warning, because if I'm in the fast lane of a busy M25, I'd prefer to ruin the engine and get to the hard shoulder.

Fury1630 wrote:Going back to basics (Dick will correct me if I'm wrong) the engine won't die as a result of no oil pressure. It dies because without pressure the oil in the bearings is not replaced & overheats, the bearings overheat & the engine seizes, so the time you have is measured in tens of seconds.

The normal oil pressure light switch fires at 5psi, so only lights when you REALLY have a problem. I fitted one that lights below 25psi. I had an oil leak a while back & noticed the oil light flickering under acceleration, so I stopped & found the problem before it became serious, but there was no damage to the engine from the short term lack of pressure

Yes spot on an engine that has lost its oil can still produce some pressure as the pump will be damp and it will pump air this may be enough to put a standard oil switch light out if its spinning fast.
The high pressure switch is the way to go (25psi) it will be on when cranking but if it comes on when driving you could save the engine. As I said put a good light just off you line of sight when driving and you will see it. Your be surprised how quick you will react to it. These switches are a direct replacement of most oil switches if you have the twin sender for both gauge and light then you need to install the Tee piece.

Been meaning to do something like this for years might have saved my last engine.

locost220 wrote:Been meaning to do something like this for years might have saved my last engine.

Pintos tend to have low oil pressure at tick over and a high pressure switch will flicker...

My light flickers at idle after a track session, but I got used to it and can check the gauge if I'm worried.