10 replies to this topic

[DeadSquare]

Clive Trickey , the C.C.C. pagan god of mini tuning, used to recommend having the highest possible oil pressure.

 

Given that pressurising oil takes power, how much oil pressure is too little?

[nicklouse]

ah this old nugget. much has to do with the oil used and the usage of the car.

 

pressure is made up by three things. the ability to pump. the ability of the parts to resist the pumping action and the spec of the oil.

 

that is to say on one engine you could have (numbers plucked from the sky) 70psi on a 20-50 and 40psi with a synthetic 5-40

[DeadSquare]

Ponder this.  The "little end" has as much piston pressure as the "big end" but a much smaller surface area and NO oil pressure supply.

[Spider]

Ponder this.  The "little end" has as much piston pressure as the "big end" but a much smaller surface area and NO oil pressure supply.

 

totally different kettle of fish and each doing a different job.

[nicklouse]

Ponder this.  The "little end" has as much piston pressure as the "big end" but a much smaller surface area and NO oil pressure supply.

and that has nothing to do with your original ,and only, question.

 

ponder this then,

you could then guess that it gets all the lube it needs from getting splashed? so why do people run windage trays with no issues?

 

see above.

[DeadSquare]

At the 1969 Mid Ohio CanAm, Bruce Mclaren did the last 10 or so laps with no oil pressure

 

 

Ponder this.  The "little end" has as much piston pressure as the "big end" but a much smaller surface area and NO oil pressure supply.

and that has nothing to do with your original ,and only, question.

 

ponder this then,

you could then guess that it gets all the lube it needs from getting splashed? so why do people run windage trays with no issues?

 

see above.

 

 

 

Talking of "splash",  I used to own a Marendaz that had been fitted with a 1919 2.63 Litre straight six Essex engine.

 

The big ends had "dippers" that "splashed" in the sump oil, and the block above the mains had grooves that encouraged oil to trickle down to the bearings.

[mini13]

again, a totaly different situation,  what was the RPM range of the Marendaz,

 

hang on, what went in it?? 

[slidehammer]

I would say that over high oil pressure is both a waste of power (very slightly) and totally unnecessary and will promote oil leaks, Something which the A series needs no help with! I seem to remember David Vizzard having a totally different opinion on this, what you want is good consistent oil pressure. I would think around 75 psi cold and 35 psi warm at idle would be a good start point.

Edited by slidehammer, 07 June 2018 - 01:30 PM.

[DeadSquare]

again, a totaly different situation,  what was the RPM range of the Marendaz,

 

hang on, what went in it?? 

 

It motored at 2,500 to 3,000 Rpm, but 4,500 to 5,000 overtaking.

 

The later Essex Terraplane was the "Jag" of the american 1930's

[Spider]

There's some info on Oil Pressure here;-

 

http://www.theminifo...07866-oil-pump/

[DeadSquare]

There's some info on Oil Pressure here;-

 

http://www.theminifo...07866-oil-pump/

 

 

Very interesting read,  thank you for directing me to it