Morris Minor Owners Club

Before starting my 1380cc engine I always take the plugs out, prime the oil pump and then turn over the engine till at least 70lb/in sq has been reached on the gauge (and then turned over a few seconds more to get the oil all around the engine)- refit the plugs and start the engine; it saves that special crank and those expensive bearings
Whilst the procedure is not practical for normal use I certainly would not switch on the ignition to start my quite high compression engine unless the pump has been primed and the oil pressure is up.
So to answer the original question 65 -70lb/in sq oil pressure is good and not too high. Better that way than too low OUCH .

Boomlander wrote:
So conversely does a lower pressure mean a higher flow rate?

That's more perverse than converse matey
And certainly unlikely to impress Socrates.
Especially since he is long dead.
But nice try

The subject is too high an oil pressure.
Within that parameter the pressure was too high because the oil was too viscous.
Because the oil was too viscous the oil flowed too slowly through the engine.

If you follow Smithskids double relief valve suggestion you will get a lower pressure.
You will also get a lower flow rate through the engine.
Hence his advice "Don't rev too hard until it is warmed up."
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smithskids wrote:If the bearing clearance has increased you do get an increase in oil flow until the flow capacity of the relief valve settings and the pump are reached. Our oroblem on the medium speed diesels was cold start up 90-100 psi causing erosion of the flashing on the aluminium tin bearing shells, plus sometimes the oil filter pack would collapse due to the excessive start up pressure on one side of the oil filter and the subsequent passage of dirt out of the filters being carried in to the bearings. Some ships had electric lub oil pumps and the start up pressure could be controlled at say 30 psi until the engine warmed up then the pressure could be regulated to 60 psi normal running pressure. With an engine driven pump you have to rely on the relief v/v system to keep the pressure within safe limits. Getting back to the original question though nothing wrong with the pressures you have quoted.

Why didn't you fit sump heaters?

Or light bonfires under the sump like the Russkies did during WW2?
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philthehill wrote:Before starting my 1380cc engine I always take the plugs out, prime the oil pump and then turn over the engine till at least 70lb/in sq has been reached on the gauge (and then turned over a few seconds more to get the oil all around the engine)- refit the plugs and start the engine; it saves that special crank and those expensive bearings
Whilst the procedure is not practical for normal use I certainly would not switch on the ignition to start my quite high compression engine unless the pump has been primed and the oil pressure is up.
So to answer the original question 65 -70lb/in sq oil pressure is good and not too high. Better that way than too low OUCH .

Yeah well, what's sauce for the goose ain't sauce for the gander.

I prefer a grade of oil that gives a 60 psi pressure when running, and 15 psi at idle.
Can't see any point in wasting petrol and power pumping oil that's too thick and then just dumping it down the relief valve.
Especially since it could be risking my bearings and bearings.
Risking them with a low flow rate.

If you fit a kill switch to your ignition you could save yourself a lot of bother.
Before you start, you close the kill switch.
Turn the engine over on the starter.
Open the kill switch when you come up to pressure.
And Charlie's your aunt.

If you are really into these things, how about: -
An electric sump heater to warm your engine oil before you start
An electric block heater to warm your engine before you start.
An electric priming pump to bring your engine to cranking pressure before you fire it up.

All readily available.
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When running Minis in the 60's, there used to be an aftermarket kit, that would delay starting electrics until good(can't remember the actual pressure) oil pressure was achieved. You had to have a good battery, on a cold morning, but it worked for me I'm sure extending the life of my rattling Min.
Anybody know if they are still about? Googled it but nothing comes op.

123
Many thanks for your observations.
With an oil pump and bearings in good condition even a normal 20/50 grade oil will always be in the process of being dumped past the oil pressure relief valve whether the engine oil is hot or cold.
As you are no doubt aware the flow of engine oil is limited/controlled by the output of the oil pump and the pressure is controlled by the oil pressure relief valve.
Whilst your suggestions are reasonable I will continue to first start my 1380cc engine as described above as the procedure has proved to work very well over many years of competitive engine use.
The engine bearings have always been regularly inspected and have always been found to be in excellent condition.
As regards rapid engine warming - my Minor is only fitted with an electric water pump that does not circulate water until the engine water temperature reaches a pre-determined temperature and thereafter coolant circulation is controlled electronically.
I also have an isolation gate valve alongside the drivers seat that can be used to control the flow of water from the engine to the radiator. So between the two the engine can be made to warm up very quickly.

Midget
You could wire a earth return into the ignition circuit through an adjustable high pressure oil pressure switch http://www.ebay.co.uk/itm/Racetech-Adju ... 4d2bb726c6 fitted to a 'T' piece at the oil pressure switch so that the ignition is not activated till the oil pressure is up to what ever the oil pressure switch is set to.
If the oil pressure fails below the required setting the ignition cuts and the engine is somewhat saved.
Consideration could be given to incorporating the following:-

https://www.merlinmotorsport.co.uk/p/ac ... ve25-40-60

https://www.merlinmotorsport.co.uk/s/oi ... m/accusump

midget wrote:When running Minis in the 60's, there used to be an aftermarket kit, that would delay starting electrics until good(can't remember the actual pressure) oil pressure was achieved. You had to have a good battery, on a cold morning, but it worked for me I'm sure extending the life of my rattling Min.
Anybody know if they are still about? Googled it but nothing comes op.

I think you will find an oil pressure light switch will do that job for you.
Simply use it to earth the live side of your contact breaker.
You can get switches that operate at different pressures.

All the best.
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philthehill wrote:123
normal 20/50 grade oil will always be in the process of being dumped

What do you mean by a normal 20/50 oil please?
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123
A normal 20/50 grade oil as referred to by me is a 20/50 grade oil obtainable from the likes of Halfords.
Phil

Or Morrisons/Asda/Wilkinson...all perfectly good enough for a standard A series

bmc
Quite
Also to clarify the above where I have referred to using an adjustable oil pressure switch to interrupt the power to the distributer - If your oil pressure switch goes direct to earth some form of resister must be used between the power feed and the oil pressure switch/earth as power that should have gone through the coil/distributer cannot be taken straight to earth other wise you will/may have a direct short to earth with dire consequences

I think the intention is to earth the coil feed TO the dizzy, thus the coil is the resistor..... I did have the same concern when I first read through

philthehill wrote:123
A normal 20/50 grade oil as referred to by me is a 20/50 grade oil obtainable from the likes of Halfords.
Phil

Does it contain dispersant additives please?
I looked it up on Halfords site.
The only technical spec I could find is obsolete
So that was the end of the line.
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bmcecosse wrote:Or Morrisons/Asda/Wilkinson...all perfectly good enough for a standard A series

To my mind there are two generations of A-series engines.
The M1 generation.
And the pre-M1 generation.

The M1 turned out to be an engine killer.
New types of oil were developed to cope with it
To cope with the dreaded "Black Death".

The two generations of A-series are easily identified.
One has a by-pass filter.
The other a full flow filter.

One benefits from oil with dispersant additives.
The other benefits from oil without dispersant additives.

One benefits from so-called "Detergent" oils.
One benefits from non "Detergent" oils.
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philthehill wrote:bmc
Quite
Also to clarify the above where I have referred to using an adjustable oil pressure switch to interrupt the power to the distributer - If your oil pressure switch goes direct to earth some form of resister must be used between the power feed and the oil pressure switch/earth as power that should have gone through the coil/distributer cannot be taken straight to earth other wise you will/may have a direct short to earth with dire consequences

How long does it take to crank an engine up to pressure?
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Depends on the state/condition of the engine surely?

midget wrote:Depends on the state/condition of the engine surely?

Could be

What's the longest you've known?
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Can't be more than 5/6 seconds--seems longer though, and won't rattle for long.
All to do with the oil draining out of worn bearings/pump when stopped and having to pump it all back again when started.
As I said, winding/pumping with the starter motor (to prime up the pressure) is kinder than firing up straight away.

midget wrote:Can't be more than 5/6 seconds--seems longer though, and won't rattle for long.
All to do with the oil draining out of worn bearings/pump when stopped and having to pump it all back again when started.
As I said, winding/pumping with the starter motor (to prime up the pressure) is kinder than firing up straight away.

Yeah, Ok.
How hot's the coil going to going to get in 6 seconds cranking?
Bearing in there's only 9v going through the coil.

I'll give you a low-tech solution.
Leave your choke in when you first start your engine.
Wait until the oil comes up to pressure.
Then pull the choke out.
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Yep, that helps---when its cold---Whatyado when hot