Thanks Phil for setting me straight. I kindof fell in love
with my infinitesimal argument. I ran a quick experiment
with a turntable and a couple of glasses of water. I
filled both to the same level. One contained just water,
the other contained 50% water and 50% coins by
volume. I then spun the turntable to see the effects
of the g forces. You are correct. It seems that the water
doesn't care what's below it ( more water or a solid);
the angle that the water assumes relative to the
horizontal was the same for both glasses. I stand
corrected. Thanks for the illumination, and thanks
for the agreement, that regardless of the depth of
the sump, the pickup should be placed as low as
possible. Sorry if I mislead anyone. :-)
David
Phil Ethier wrote:
>First, I agree that ideally one ought to run the oil pickup as low as
>possible.
>
>Second, I can't agree with either the method or conclusion in David's
>message.
>
>Instead of thought experiments with imaginary layers, lets use some actual
>physical principles, one step at a time.
>
>The surface of a liquid will be perpendicular to the G-force vector.
>
>The G-force vector of a car cornering at 1 Gee is at 45 degrees from the
>horizontal.
>
>The angle of the oil in a sump in a car cornering at 1 Gee will be 45
>degrees from the horizontal.
>
>The angle of the oil in a sump in a car cornering at 1 Gee will be 45
>degrees, plus the lean angle of the car, from the angle of the car at rest.
>
>These effects are independent of sump depth.
>
>Phil Ethier West Side Saint Paul Minnesota USA
>1970 Lotus Europa 65/2597, 1992 Saturn SL2, 1986 Suburban, 1962 TR4 CT2846L
>pethier@isd.net http://www.mnautox.com/ http://www.lotusowners.com
>
>----- Original Message -----
>From: "David"
>To: "TR250"
>Sent: Thursday, February 06, 2003 6:12 PM
>Subject: Re: deep pan
>
>
>>Yes, ideally you would extend the pickup to about .5 in
>>from the bottom of the pan. The trouble is that as you
>>deepen the pan while still maintaining the same oil level
>>at the dipstick, and without extending the oil pump pickup,
>>you more readily run the risk of exposing the pick up to
>>air. This is so because given the same lateral G forces,
>>and given what I said above, a deeper pan will result in
>>oil sloshing higher on the outside of the pan and lower
>>on the inside of the pan. You can prove this to yourself
>>by imagining taking the stock pan and doubling its depth.
>>Now consider the oil as 2 separate levels. There's the
>>upper level which consists of the oil in a stock pan, then
>>there's the lower level which consists of an equal amount
>>of oil but placed below the upper level. If you consider
>>how G forces act on these to layers independently then
>>you can add them up to get the resultant.
>>
>
>How does the G-force know to act on these layers independently?
>
>What if you imagined three layers? Would you get a different result?
>
>>What happens
>>is that both layers are effected by the G force identically.
>>They both slosh to the outside by the same height and
>>lower on the inside by the same height. Now if you stack
>>both of there layers, their respective sloshing accumulates.
>>In reality the lower level adds less to the resultant because
>>the weight of the upper level flattens it's G force effect. The
>>outcome is that the deeper pan climbs up the outside wall
>>and falls on the inside wall to a greater degree than the
>>shallow pan. Thus the oil pickup should be lowered.
>>
>>Sorry for the long winded explanation,
>>Dave
>>
>>CarlSereda@aol.com wrote:
>>
>>>David
>>>i've heard the deeper finned oil pans hold more oil (maybe two quarts
>>>extra) but never any mention of having to extend the pump pickup.. you
>>>still have 5 quarts above the pickup right?
>>>Carl
>>>'63 TR4 since '74 .. as soon as i think i know something i find out i
>>>don't
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