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50psi when driving is good. Some people report 70+. But 50 to 70 is good. As you say assuming the gauge is reading accurate etc.

 

On tick over after warm up 20psi would be OK but lower isn;t a panic.

 

Roger

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How quickly did the water temp rise? Did it steady? What's the state of the engine - has it been rebuilt and have the waterways been flushed out? New or old water pump? Mine doesn't take long to come up to temperature, a few minutes if I run it in the garage.

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Never understood anything about the reading "value" on the oil gauge. My reading is: Pressure = OK / No pressure = NOK. ON/OFF It eludes me...

Edited by Geko
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Never understood anything about the reading "value" on the oil gauge. My reading is: Pressure = OK / No pressure = NOK. ON/OFF It eludes me...

Your experience is most likely to have been with OK only vehicles.

My Kiwi vet student fellow boarders lent me their 'bomb' during their Xmas vacations back in NZ.

During the 50 mile drive to and from the 'Gong the oil pressure gradually went from about 50 psi down to about 5psi as the oil heated and thinned and started leaking past the worn big ends instead of going elsewhere. As it approached 5 and below you had to stop, let it cool for about an hour, then complete the rest of the trip before it got to 5 psi again.

The gauge was an important indicator of when to stop.

 

 

My 4A readings are similar to Roger's.

Edited by littlejim
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Your experience is most likely to have been with OK only vehicles.

My Kiwi vet student fellow boarders lent me their 'bomb' during their Xmas vacations back in NZ.

During the 50 mile drive to and from the 'Gong the oil pressure gradually went from about 50 psi down to about 5psi as the oil heated and thinned and started leaking past the worn big ends instead of going elsewhere. As it approached 5 and below you had to stop, let it cool for about an hour, then complete the rest of the trip before it got to 5 psi again.

The gauge was an important indicator of when to stop.

 

 

My 4A readings are similar to Roger's.

I had one NOK experience with an Austin Healey Sprite and there was nothing really gradual - no early warning I could read from the gauge ahead of the disaster. From memory the reading was something like: OK/claclaclac...clac/NOK :(

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My 4 runs at 20-25 at warm idle, up to 75-80 under full load and around the 55 cruising

 

never rebuilt to the best of my knowledge

 

Graze

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thanks guys

run car in garage oil 50psi , not drove it yet

water pressure rises quickly 2mins then at top of temp gauge while stood in garage !

 

engine has had new pots and a conversion to un leaded .

 

fitted old water pump !!

 

going to set up timing tomoz , is this done while engine hot or best when cold .

 

cheers coolie

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Sounds like you have an air lock in the water system. Oil pressure is easily adjustable on a 4 pot engine.

Stuart.

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Another variable is the temperature sender. They vary, so if you have changed it during the rebuild it might not be reading accurately, or sensibly - I doubt they're ever accurate. Lots of reading on the forums about that.

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As Stuart says the oil pressure is adjustable, book value, if you are using a good quality mineral 20/50, is between 65 and 75lbs/sq. inch at 2000 rpm @ normal running temp, falling to around 50lbs/sq.inch with sustained high speed running, ... back in the day that was 5k plus rpm in top O/D for a couple of hours up the M1 (then AC started testing their Cobras .......) if this drops it to 30psi, or for track use fit an oil cooler, don't forget to include a thermostat.

Cheers Rob

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