Cutting steel with high pressure water is common place nowadays...also SWS's post about "having a dry start-up on the cylinder walls" ,number 10 I believe,this is where having a good motor oil comes into play where by it clings to metal at rest.quote:
Originally posted by ekpolk:
Yeah, I thought it was almost amusing too . . . until I considered what it meant in terms of oil supply volume to critical parts.quote:
Originally posted by Greaser:
An engine turning at 3000 rpm will turn oil into a force that will tear the flesh from your hands if you could hold your hand under a running engine at that speed.Windage trays will yeild 10-20 HP in a HO engine just by letting the reciprocating assembly not get oil spray back on itself from the sump.Vapour coating your cylinder walls is almost amusing
Another "violence of oil" thought: in Naval Aviation training, we're taught to get the **** away from "pink clouds," which is what you see in the vicinity of small high pressure hydraulic leaks (atomizing fluid). Typical aircraft systems run at 3000 psi, and the flow from a small leak can slice your fingers off like a liquid laser beam. Trust me, I've got plenty of respect for moving oil.
Nice animation of how oil flows in an engine
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MolaKule
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From one Scientist/Engineer to another:
Go back to your physics "oscillation/rotation" theory and recall the following:
Tangential Velocity, v = w x r where omega, w, is the rotational velocity and r is the radius.
In 1 RPM there are 2 x pi radians/60 s = 0.105 radians of revolution per second.
Multiply previous answer, w = 0.105 x 6000 RPM = 628 radians /sec. That is your rotational velocity, w for 6000 RPM's.
Take v = 628 radians/s x 0.33 ft = 207 ft./s. This is your linear velocity v for a particle of oil escaping from the edge of a 4" radius crank.
The conversion factor to mph is 0.68 so,
207 ft./s x 0.68 mph.s/ft. = 141 mph.
Hope that helps.
[ April 25, 2004, 07:11 PM: Message edited by: MolaKule ]
Go back to your physics "oscillation/rotation" theory and recall the following:
Tangential Velocity, v = w x r where omega, w, is the rotational velocity and r is the radius.
In 1 RPM there are 2 x pi radians/60 s = 0.105 radians of revolution per second.
Multiply previous answer, w = 0.105 x 6000 RPM = 628 radians /sec. That is your rotational velocity, w for 6000 RPM's.
Take v = 628 radians/s x 0.33 ft = 207 ft./s. This is your linear velocity v for a particle of oil escaping from the edge of a 4" radius crank.
The conversion factor to mph is 0.68 so,
207 ft./s x 0.68 mph.s/ft. = 141 mph.
Hope that helps.
[ April 25, 2004, 07:11 PM: Message edited by: MolaKule ]
FWIW my 4.5L I-6 Lexus (Toyota motor) has oil nozzles that cool the bottom of the piston and cylinder walls, they only work at higher oil pressure, Toyota does not seam to worry about over oiling the cylinder walls, maybe they did some extra or different oil control rings to make up for the extra oil? Oil consumption is usually good on this motor mine has a slight rear main seal or pan arch leak (have not figured out witch yet) but still only uses 1/2Qt /3,000 if not for the leak I think my consumption would be very low for a motor with 109K miles on the clock
From the flow diagram in the manual on this motor only big end bearing of the connecting rod is pressure lubricated, there is no drilled oil passage to get oil from the “big end” to the “little end” of the connecting rod to lube the wrist pin, I am surprised how many of the moving parts of this motor are splash/mist lubricated especially in the valve rain only the cam bearings are pressure lubed
From the flow diagram in the manual on this motor only big end bearing of the connecting rod is pressure lubricated, there is no drilled oil passage to get oil from the “big end” to the “little end” of the connecting rod to lube the wrist pin, I am surprised how many of the moving parts of this motor are splash/mist lubricated especially in the valve rain only the cam bearings are pressure lubed
That's all interesting, but then one realizes that you guys are talking about 3,000 psi and up systems.
Oil flung off a 4 inch stroke crank turning 6,000 rpm is moving about 180 mph and has a velicity head equivilant to about 300 psi. It's not concentrated like a pinhole leak or nozzle. Also note that paint holds up just fine inside an engine.
I had seen, years ago, a conrod with a drilled oil passage up to the wrist pin, and assumed, mistakenly it looks like, that all modern engines featured this form of pressure lube. Digging a bit deeper, the below image is from the 2003 Camry manual. While there is an oil hole into the wrist pin bushing, the oil does not seem to come up from the rod. Whether the source is oil flung from the crank or nozzles, I can't tell. Any 1MZ wizards out there?
SWS is spot on.
what's interesting is that the engine in the animation is obviously a small block american V8. pushrod, inline valve head, with the pump driven off the cam. yet small block V8s are specific examples of engines without any such oil feed through the rods.
-michael
what's interesting is that the engine in the animation is obviously a small block american V8. pushrod, inline valve head, with the pump driven off the cam. yet small block V8s are specific examples of engines without any such oil feed through the rods.
-michael
Then add in the big end bearing radius and you get about 180 mph off the outer side of the big end.
Looks like it was drafted by someone who made the same assumption I did. . .
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