Changing mind on oil changes

[Russell King]

UMMMM it's 2024.

Doh thanks for pointing out my failing memory of cold weather AND what year it is now.

corrected that mistake

 

[Fordtech86]

 

[hagrid]

Liquefied human, probably.

 

[ruger1980]

"GeoHorn: How So?"

Overly high oil pressure can erode a rod or main bearing, from the lube hole area, where the oil enters the bearing, similar to the same way high water erodes away a stream bank. This doesn't apply to needle or ball type bearings.

This not how friction type bearings in an engine are lubricated. Oil pressure has no bearing on the oil in the bearing, the oil is drawn into the clearance between the crankshaft and bearing it is not forced. Please do some research and you will learn.

 

[ruger1980]

Its not quite that simple.

Fill your loader bucket with gravel and raise it to full height and leave it there. Whats the pressure in the base end of the cylinders and how much flow is going through them?

Or if you like raise it halfway when empty and then shovel it full. What was the pressure before and after filling and how much oil flowed?

Dan

Actually is it quite that simple. When you have a load in the bucket whether it be the weight of the bucket and loader arms itself or with a load in the bucket you have a force acting on the cylinder rod trying to force oil from the barrel side of the cylinder. This force is trying to create flow ,and to a very slight degree does. The valve being closed, and the rest of the circuit becomes resistance to flow. This is measured as pressure.
It is no different than when you are trying to lift an object with a hydraulic jack, you are attempting to force oil into a closed system and thus create a circuit where pressure can be measured.

 

[Chad D.]

When we have a discussion go this sideways in my home, I typically ruffle up the hair on my kids’ heads and say, “Girls, it doesn’t really matter. You’re both pretty.”

Oddly, it doesn’t matter if I’m talking to a son or a daughter. They get the point.

 

[TheOldHokie]

Actually is it quite that simple. When you have a load in the bucket whether it be the weight of the bucket and loader arms itself or with a load in the bucket you have a force acting on the cylinder rod trying to force oil from the barrel side of the cylinder. This force is trying to create flow ,and to a very slight degree does. The valve being closed, and the rest of the circuit becomes resistance to flow. This is measured as pressure.
It is no different than when you are trying to lift an object with a hydraulic jack, you are attempting to force oil into a closed system and thus create a circuit where pressure can be measured.

You could have written that just as accurately and never used the word flow. From a physics perspective flow is irrelevant:

"Just like the solid rod the incompressible fluid is transmitting an applied force. Unlike the solid rod its transmitting it both axially and radially.".

When we introduce the concept of flow in the context of transmitted force (e.g. pressure) many people get confused. Flow has its place but not here.

Dan

 

[Nicksacco]

View attachment 120396

CLASSIC! Truly a classic!

 

[mcmxi]

When we introduce the concept of flow in the context of transmitted force (e.g. pressure) many people get confused. Flow has its place but not here.

You're just muddying the waters. Go back and read the OP. The issue is about engine oil pressure and an engine oil pressure gauge. You're the only one talking about hydraulic oil which has no bearing here (no pun intended). Flow is absolutely relevant here, and in this situation, the only indicator we have that oil is moving in the system is the pressure gauge.

 

[hagrid]

the only indicator we have that oil is moving in the system is the pressure gauge.

I wish it could be otherwise.

 

[GeoHorn]

I wish it could be otherwise.

THAT would indeed be an interesting factoid…..to know the lpm/gpm of oil flow…. as it is Flow which continuously removes heat from the bearing…..(regardless of which type of bearing being discussed which MountainMeadows denies having introduced to the conversation..)

 

[MountainMeadows]

I guess we can agree to disagree. I'm not the only one who thinks excessively high oil pressure can wash out babbit bearings.

Hear are some opinions from others:

Too much ( high) pressure ruins as many engines as low oil pressure. Not just washing the bearings but also hard on the filter etc not to mention the power required to run it. 90-100 lbs is way too much pressure. I agree with above post 7 psi per 1000 rpm is plenty. Now VOLUME on the other hand is another story.

I have seen many failures over the years with too much pressure in one area or another..

Root too much oil pressure? Somewhere between 110 and 125 (depending on the bearing manufacturer) the oil will wash the babbit off the inserts.
It takes Horsepower to turn the oil pump. Higher pressures take more horsepower ... I have always been told that you need 5 to 7 pounds of oil pressure for every one thousand RPMS in a SBC. When I worked @ the machine shop ... back in the late 60's ... the old guy there said too much pressure just " washed the bearings " ... not really lubricated them ...

You don't need a high volume oil pump, robs horsepower, can twist oil pump driveshafts in half, blow oil filters up, or off, lastly to high oil pressure will actually cause a vacuum (from the fast moving oil) between the bearing and journal starving it for oil, you do not need no more than 60 psi hot at rpm, and no less than 20 psi hot at idle.

Bob's your uncle..........

 

[GreensvilleJay]

You could add a flow meter after the pump,before the block.......add one on both sides of the filter and you could monitor when the filter needs to be changed......

..BTW Bob WAS my uncle, helped build the Alaskan Highway, knew where he 'parked' 3 or 4 brand new big dozers. Always said should go back, dig them up, fresh batteries and fuel, they'd run just fine....

 

[WFM]

This site seems to be riddled with oil maniacs.
Change it when it is hot out, change it on Friday, change it after no use, change it when a tire goes flat?
Logic is missing EVERYWHERE in today's society !!!

Just because it's fall and I have 50 hrs on my oil and I change my oil and filter every fall there's no need to single me out !!!

 

[The Evil Twin]

Are the engine oil pumps on these little machines positive displacement pumps?

 

[DustyRusty]

Just because it's fall and I have 50 hrs on my oil and I change my oil and filter every fall there's no need to single me out !!!

This site doesn't single out any one person. Everyone is open to ridicule. If you can't stand the heat, get out of the kitchen.

 

[D2Cat]

I guess we can agree to disagree. I'm not the only one who thinks excessively high oil pressure can wash out babbit bearings.

Hear are some opinions from others:

Too much ( high) pressure ruins as many engines as low oil pressure. Not just washing the bearings but also hard on the filter etc not to mention the power required to run it. 90-100 lbs is way too much pressure. I agree with above post 7 psi per 1000 rpm is plenty. Now VOLUME on the other hand is another story.

I have seen many failures over the years with too much pressure in one area or another..

Root too much oil pressure? Somewhere between 110 and 125 (depending on the bearing manufacturer) the oil will wash the babbit off the inserts.
It takes Horsepower to turn the oil pump. Higher pressures take more horsepower ... I have always been told that you need 5 to 7 pounds of oil pressure for every one thousand RPMS in a SBC. When I worked @ the machine shop ... back in the late 60's ... the old guy there said too much pressure just " washed the bearings " ... not really lubricated them ...

Here's some information on bearing lubrication and destruction. High oil pressure is not mentioned, but lack of oil volume or slow RPM are mentioned.

Babbitt: The Other Bearing Lubrication

Journal bearings play a critical role in equipment with large and high-speed rotating components. They primarily are used in machines with more than 500 horsepower and that operate at speeds of...

www.machinerylubrication.com

 

[GreensvilleJay]

yeesh, I got two blocks of Babbit in the garage.tried selling them,couldn't give them away to neighbour that has a Model A.

 

[Kubota Newbie]

Sorry for starting this but some pretty interesting reading. Primary reason I was thinking about this issue was the washout/ bearing erosion issue. I too have heard that for years, but I've taken dozens of different motors apart, some without any bypass system at all that regularly ran high pressures and I've never seen it in person. Bearing failure of all other sorts. But not anything in a motor that just ran high pressure, granted, those were not getting many hours, but still....
Usually dirt or lack of oil are the culprit.