Morris Minor Owners Club

Hello

I am considering fitting a oil pressure gauge to my 1098cc engine.

How easy is it to remove the old oil pressure switch from the block as i have heard of a few breaking when removed leaving the threaded part stuck in the block.

I have no real reason for fitting a pressure gauge other than out of interest so if there is a likelihood of causing more problems while fitting i will leave it be.

Thanks
Donald

Maybe try to loosen it with without too much force, and see if wants to move. If not leave or take the gamble !
Personally I find the lack of gauges on a Minor, rather comforting. Perhaps more desirable with a tuned vehicle. I’m quite happy with the Minors warning lamps. It’s a personal thing. Good luck.

As Les has said, it's personal preference. I find the green oil warning lamp in earlier cars aren't very conspicuous in bright sunshine. So a gauge can be a bonus in that situation. However, the later cars amber warning lamp seem to have better visibility.
If you do decide to fit a gauge, then it's worth fitting a 'T' piece so you can keep the warning lamp and learning what is the 'normal' oil pressure range for your car. I've had 3 different Minors and they all ran at different oil pressures once warmed up. Generally, if the pressure deviates significantly from the normal range, then it could indicate a problem.

If you go for it Donald use one of these adaptors, as suggested to me by philthehill, to take the pressure line off of the oil pipe that goes from the engine block to the filter.

https://www.ebay.co.uk/itm/CLASSIC-MIN ... 890.l49286

It saves the distributor getting in the way, which is how I ended up snapping a different type of adaptor.

It also leaves your existing oil pressure warning light untouched.

You may also need to drill a hole (or widen existing one) in your bulkhead to get the pipe fixings through.

Remember a little loctite thread lock too.

Thanks for all your thoughts on this.

John I like your idea of the adaptor, will save any bother removing the current sensor.

I have now ordered the adaptor.

Thanks again
Donald

Can we have a consensus of oil pressure?

What does your moggie run at Cold/hot ?

John ;-)

Here is the up to date link for the oil pressure gauge banjo bolt take off adapter.
https://www.ebay.co.uk/itm/165714990063 ... SwHiNivGim
The above adapter is the best way of tapping into the oil system and is easy to fit.

Sleeper wrote: ↑Mon Feb 27, 2023 12:46 pm Can we have a consensus of oil pressure?

What does your moggie run at Cold/hot ?

John ;-)

60 psi cold, 45-50 psi hot, but how accurate the gauge is is anyone's guess.
Also it depends on the revs at the time of course.

I know most oil pressure gauges are 'mechanical', but are there any downsides to fitting an electronic version?

I have an Smiths electric water temp gauge which works perfectly well, and I'd like to fit a Smiths oil pressure gauge (or a dual water temp/oil pressure electronic one if Smiths do one) and routing the wires would seem an easier option than fitting the oil pressure tube.

Any thoughts most welcome!

Pete

I've used electric oil pressure gauges for many years on Minors, other cars, and other applications. They have always worked perfectly. To my mind, they are much easier and neater to fit and there is no danger of a fractured capillary tube leading to an oil leak - I've not heard of that happening, but it has always seemed like a risk. Vacuum advance diaphragms and pipes fail, so why shouldn't a mechanical oil pressure gauge?

Many thanks for that! I've just been in told by Smiths instruments that their dual water temp/oil pressure gauge in electronic format will be launched this autumn, but I can wait!

On a brand new engine ours never drops much below 50psi, we have the mini smiths temp and oil pressure gauges with an adaptor on the original oil pressure port that allows the switch and pipe to be fitted (we don't have a distributor though).

moggiethouable wrote: ↑Mon Feb 27, 2023 1:24 pm

Sleeper wrote: ↑Mon Feb 27, 2023 12:46 pm Can we have a consensus of oil pressure?

What does your moggie run at Cold/hot ?

John ;-)

60 psi cold, 45-50 psi hot, but how accurate the gauge is is anyone's guess.
Also it depends on the revs at the time of course.

My slightly modified 948, rebuilt 10 years ago, maintains 40 psi at idle when properly hot, and rises to 60 psi (regulated by the pressure relief valve) from around 2000 rpm and above hot. By 'hot' I mean after a sustained high speed run.

When it's cold the pressure relief valve struggles and pressure rises a little higher, to around 70 psi.

There is no need to over egg the oil pressure. 50psi when hot and 25psi at idle is all you need.
Having high oil pressure creates heat and saps engine power.
The oil temperature when hot should be around 100 - 107 degrees C and no lower than 80 degrees C.
To get the correct oil pressure and so control the heat an adjustable oil pressure relief valve should be fitted or the existing oil pressure relief valve modified.
One of the useful side effects of having circulating oil is its ability to carry heat away from bearings and moving parts.

philthehill wrote: ↑Tue Feb 28, 2023 4:59 pm There is no need to over egg the oil pressure. 50psi when hot and 25psi at idle is all you need.
Having high oil pressure creates heat and saps engine power.
The oil temperature when hot should be around 100 - 107 degrees C and no lower than 80 degrees C.
To get the correct oil pressure and so control the heat an adjustable oil pressure relief valve should be fitted or the existing oil pressure relief valve modified.
One of the useful side effects of having circulating oil is its ability to carry heat away from bearings and moving parts.

I am not sure that anyone was actually trying to 'overegg' oil pressure? People were replying to a request regarding readings they see.

I am happy with mine as it appears to be to be within spec according to the workshop manual - 60 psi under 'normal running' and above the minimum cited 15 psi at all times when 'idling'. the fact that it peaks at 60 psi suggests to me there is no need to play around with the pressure relief valve - my car is not a track car

As ever, we head further off topic

The point being made is that high oil pressure is not desirable or useful.
Too many people think that high oil pressure is good. What is good is high oil flow around the engine.
My reply above is certainly not going off topic as it relates to oil pressure readings and the oil pressure that should be aimed for and appear on the oil pressure gauge.

Some engines have virtually no oil pressure at idle and run for thousands of miles like it Rover V8's are a classic example , my Range rover barely moves the needle when hot, even the re-built lump in my TR7V8 doesen't make much over 10 psi.

Modern cars have electronically controlled variable displacement oil pumps, these deliberatly drop to a few psi at idle and low loads to improve fuel efficiency.

As Phil says it's flow you need not pressure.

High pressure is easy to get, just block a few oil ways.....

It's very similar to your Blood Pressure, if your BP goes up just because of a little exercise, it's not good.
Your heart has increased the pumping rate to increase the flow, but your body should accommodate that flow by expanding blood vessels.
When it doesn't the BP goes up....

kevin s wrote: ↑Wed Mar 01, 2023 7:27 pm Some engines have virtually no oil pressure at idle and run for thousands of miles like it Rover V8's are a classic example , my Range rover barely moves the needle when hot, even the re-built lump in my TR7V8 doesen't make much over 10 psi.

Modern cars have electronically controlled variable displacement oil pumps, these deliberatly drop to a few psi at idle and low loads to improve fuel efficiency.

As Phil says it's flow you need not pressure.

I think the point here is about being within manufacturer's specs - as stated these vary.

Different vehicles have different requirements for oil pressure vs. flow - this is well known and I am not aware that anyone was suggesting otherwise? Max pressure on my T2 VW engine is meant to be 42psi, for example, and more is detrimental.

It does feel a little as though citing pressures that are as per manufacturer's spec is being frowned upon! I must apologise for my stupidity