Is bleeding necessary?
Le Mans Master
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From: Las Vegas - Just stop perpetuating myths please.
Vapor remains a problem only at low pressures.
Originally Posted by GOTAVETTEc37d
You Do Not Need To Bleed The Line , The Air Will Compress To The Same Pressure As The Oil.
Any press over 10 psi should collapse the air/vapor in the line unless not enough oil to absorb it - then the press will be sensed through the vapor without distortion. The problem is only at very low pressures like inches of water where the vapor bubble will change size and produce bad pressure readings. I guess what i'm trying to say is that at higher pressures any vapor bubbles that remain become too rigged to change shape and will transfer the system pressure without distortion. 
No i can't or don't care to explain the PV=nRT thing. 
Whew!
Hope that helps. cardo0
Drifting
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Originally Posted by cardo0
Any press over 10 psi should collapse the air/vapor in the line unless not enough oil to absorb it - then the press will be sensed through the vapor without distortion. The problem is only at very low pressures like inches of water where the vapor bubble will change size and produce bad pressure readings. I guess what i'm trying to say is that at higher pressures any vapor bubbles that remain become too rigged to change shape and will transfer the system pressure without distortion. No i can't or don't care to explain the PV=nRT thing. Whew!
Hope that helps. cardo0The Corvette mechanical pressure gage will read either air or oil pressure. If "x" psi is fed into the line feeding the gage, unless the line is mechanically blocked (kinked line, solid non-porus slugde, ball bearing, etc) the gage will read that "x" pressure. If there is air in the line it will simply be compressed to "x" psi. If there are slugs of oil in the line, those slugs will simply move to whatever position is necessary to compress any air on either side of that slug to that "x" pressure.
(The engine can supply ALL the volume of oil necessary to pressurize ANY amount of air that might be in the line.)
MIT Mechanical Engineer '77!!
Last edited by StickShiftCorvette; Mar 13, 2005 at 12:16 PM.
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From: You should have told him it would not hit 185 if you dropped it out of the back of a C130 with 4 heffalumps inside trying to get to the Golden Corral.
bleeding is not necessary. you may sue the doc that told you it was.
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Le Mans Master
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From: Las Vegas - Just stop perpetuating myths please.
Not quite what?
Originally Posted by StickShiftCorvette
Not quite.
The Corvette mechanical pressure gage will read either air or oil pressure. If "x" psi is fed into the line feeding the gage, unless the line is mechanically blocked (kinked line, solid non-porus slugde, ball bearing, etc) the gage will read that "x" pressure. If there is air in the line it will simply be compressed to "x" psi. If there are slugs of oil in the line, those slugs will simply move to whatever position is necessary to compress any air on either side of that slug to that "x" pressure.
(The engine can supply ALL the volume of oil necessary to pressurize ANY amount of air that might be in the line.)
MIT Mechanical Engineer '77!!
The Corvette mechanical pressure gage will read either air or oil pressure. If "x" psi is fed into the line feeding the gage, unless the line is mechanically blocked (kinked line, solid non-porus slugde, ball bearing, etc) the gage will read that "x" pressure. If there is air in the line it will simply be compressed to "x" psi. If there are slugs of oil in the line, those slugs will simply move to whatever position is necessary to compress any air on either side of that slug to that "x" pressure.
(The engine can supply ALL the volume of oil necessary to pressurize ANY amount of air that might be in the line.)
MIT Mechanical Engineer '77!!
U may be well educated but at low press like less than 50" wtr the vapor bubbles will compress/change shape and produce an inaccurate indication at the end of the line. I have experienced this many times and found bubbles in the sensing line must be removed for accurate low press indication. I see this all the time at the power plant where i calibrate they're gauges to know better. I do agree at higher press the pressure gets transmitted accross the air vapor.
It maybe a function of vapor press and temp but i don't need to go there to know my flowmeter is out of calibration by impierical means - tank lvl, etc.
I guess u would have to experience this for ur self to know. cardo0
Drifting
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Originally Posted by cardo0
U may be well educated but at low press like less than 50" wtr the vapor bubbles will compress/change shape and produce an inaccurate indication at the end of the line. I have experienced this many times and found bubbles in the sensing line must be removed for accurate low press indication. I see this all the time at the power plant where i calibrate they're gauges to know better. I do agree at higher press the pressure gets transmitted accross the air vapor.
It maybe a function of vapor press and temp but i don't need to go there to know my flowmeter is out of calibration by impierical means - tank lvl, etc. I guess u would have to experience this for ur self to know. cardo0
It maybe a function of vapor press and temp but i don't need to go there to know my flowmeter is out of calibration by impierical means - tank lvl, etc.
I guess u would have to experience this for ur self to know. cardo0Consequently, relative to the rate of air going into or out of solution in the oil the gage will read more than accurately enough without bleeding the line.
Le Mans Master
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From: Las Vegas - Just stop perpetuating myths please.
Back to school with u.
Originally Posted by StickShiftCorvette
The oil pump has virutally infinite volume relative to the volume found in the oil line. The engine oil pressure changes as a function of RPM until the oil pressure relief pressure is reached (or if your engine is well worn, it peaks out due to volume losses throughout the engine).
Consequently, relative to the rate of air going into or out of solution in the oil the gage will read more than accurately enough without bleeding the line.
Consequently, relative to the rate of air going into or out of solution in the oil the gage will read more than accurately enough without bleeding the line.
Well i have to disagree (again) as with engine wear the oil press tends to increase due to less restrictions through the brgs - the only relieve is in the filter bypass (inside the filter) from clogging/backpressure - something u would have known from exprience.
Also the oil in the sensing line is trapped, does not mix with the block oil in circulation and becomes saturated. But again at higher pressures it's not a problem as the air vapor bubbles act enough as a solid and transmit enough of the system press to the gauge/transmitter.
cardo0
Drifting
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Originally Posted by cardo0
Well i have to disagree (again) as with engine wear the oil press tends to increase due to less restrictions through the brgs - the only relieve is in the filter bypass (inside the filter) from clogging/backpressure - something u would have known from exprience.
Also the oil in the sensing line is trapped, does not mix with the block oil in circulation and becomes saturated. But again at higher pressures it's not a problem as the air vapor bubbles act enough as a solid and transmit enough of the system press to the gauge/transmitter.
cardo0
Also the oil in the sensing line is trapped, does not mix with the block oil in circulation and becomes saturated. But again at higher pressures it's not a problem as the air vapor bubbles act enough as a solid and transmit enough of the system press to the gauge/transmitter.
cardo0
The oil filter bypass valve ONLY bypasses the filter, and I never said anything about it. Its function is to bypass oil to the engine if the filter is clogged or the oil is too viscous (due to its weight and temperature or due to chemical degradation) to flow through the filter in the quantities supplied by the pump.
The air in the lines NEVER acts like a solid. It acts like the gas it is. Being dead headed doesn't make any difference to the gage or the oil in the engine or line.
Le Mans Master
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From: Las Vegas - Just stop perpetuating myths please.
U said relief vlv. Oil pump has regulating vlv.
Originally Posted by StickShiftCorvette
You apparently have never looked into a Chevy or aftermarket oil pump. All of them have an internal relief valve that establishes the maximum pressure delivered. That is why there are BOTH high pressure AND high volume oil pumps AND high volume/pressure pumps sold.
The oil filter bypass valve ONLY bypasses the filter, and I never said anything about it. Its function is to bypass oil to the engine if the filter is clogged or the oil is too viscous (due to its weight and temperature or due to chemical degradation) to flow through the filter in the quantities supplied by the pump.
The air in the lines NEVER acts like a solid. It acts like the gas it is. Being dead headed doesn't make any difference to the gage or the oil in the engine or line.
The oil filter bypass valve ONLY bypasses the filter, and I never said anything about it. Its function is to bypass oil to the engine if the filter is clogged or the oil is too viscous (due to its weight and temperature or due to chemical degradation) to flow through the filter in the quantities supplied by the pump.
The air in the lines NEVER acts like a solid. It acts like the gas it is. Being dead headed doesn't make any difference to the gage or the oil in the engine or line.
The oil pmp regulating vlv maintains the output press thoughtout engine life and not expected to change. But what changes are restrictions and press losses due to brg wear and the pressures gauge/transmitter will see a higher press from engine wear/less brg restriction. Again there is no relief vlv in the oil pump. This would cycle pressure all the time to open and seat the vlv.
Total dissolved gasses limit how much air vapor can be absorbed by a liquid and this a sience i don't know enough about to argue but don't care much either. And again it's at low press where the problems which air vapor (dissolved gasses) are. Your wording that it (air vapor) fully transmits pressure but doesn't compress/act like a solid is bit senseless too me. But since the result is the same i can live with it and don't know y u keep referring to it.
cardo0
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Originally Posted by cardo0
The oil pmp regulating vlv maintains the output press thoughtout engine life and not expected to change. But what changes are restrictions and press losses due to brg wear and the pressures gauge/transmitter will see a higher press from engine wear/less brg restriction. Again there is no relief vlv in the oil pump. This would cycle pressure all the time to open and seat the vlv.
Total dissolved gasses limit how much air vapor can be absorbed by a liquid and this a sience i don't know enough about to argue but don't care much either. And again it's at low press where the problems which air vapor (dissolved gasses) are. Your wording that it (air vapor) fully transmits pressure but doesn't compress/act like a solid is bit senseless too me. But since the result is the same i can live with it and don't know y u keep referring to it. cardo0
Total dissolved gasses limit how much air vapor can be absorbed by a liquid and this a sience i don't know enough about to argue but don't care much either. And again it's at low press where the problems which air vapor (dissolved gasses) are. Your wording that it (air vapor) fully transmits pressure but doesn't compress/act like a solid is bit senseless too me. But since the result is the same i can live with it and don't know y u keep referring to it.
cardo0
Le Mans Master
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From: Las Vegas - Just stop perpetuating myths please.
Maybe u need to look in the books again sssuch.
Originally Posted by sssuch
Cardo, you seem to have things backwards , there IS a pressure relief valve in the oil pump its right on the cover next to the pick-up tube opening. And as a engine wears bearing clearances increase and you will see a DROP in oil pressure. I'm an automotive master tech with 31 years experience and have rebuilt or repaired thousands of motors and thats the way it is.
What does wear is the brgs and this reduces sys press loss and again the gauge/transmitter will see more press as engine wears.
But what i don't see is hardly any posts in ur profile or where u are from/work or even a picture of ur car. For someone with 31 yrs experience u don't have much to talk about in a corvette forum?
cardo0 
Last edited by cardo0; Mar 14, 2005 at 12:39 AM. Reason: clarification
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From: Foxfield CO 1970 Convertible
My .02 cents worth...
- Air in the line to the oil pressure gauge won't matter at the low pressure in the oil system, the gauge should read OK
- The air bubbles in the oil pressure line stay bubbles. There isn't any measurable "compressing" at pressure this low
- As bearings in an engine wear, the oil pressure will *drop* since the increased clearance reduces pressure
- Air in the line to the oil pressure gauge won't matter at the low pressure in the oil system, the gauge should read OK
- The air bubbles in the oil pressure line stay bubbles. There isn't any measurable "compressing" at pressure this low
- As bearings in an engine wear, the oil pressure will *drop* since the increased clearance reduces pressure
Drifting
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Originally Posted by sssuch
Cardo, you seem to have things backwards , there IS a pressure relief valve in the oil pump its right on the cover next to the pick-up tube opening. And as a engine wears bearing clearances increase and you will see a DROP in oil pressure. I'm an automotive master tech with 31 years experience and have rebuilt or repaired thousands of motors and thats the way it is.
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Thanks StickShift, Some people seem to think they know everything because they read a parts store Chiltons manual or slept it a Holiday Inn last night 
And Cardo as far as my not knowing anything because my post count is lower than yours it just aint worth arguing with you about it . And as far as posting a pic of my car, well here you go: http://www.ls1tech.com/forums/attach...achmentid=9436
and if you like that I can send you lots more just PM me your e-mail address. And yes ALL work was done by me including the paint. Stan
And Cardo as far as my not knowing anything because my post count is lower than yours it just aint worth arguing with you about it . And as far as posting a pic of my car, well here you go: http://www.ls1tech.com/forums/attach...achmentid=9436
and if you like that I can send you lots more just PM me your e-mail address. And yes ALL work was done by me including the paint. Stan
Last edited by sssuch; Mar 15, 2005 at 12:54 AM.
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Originally Posted by foundvettelifeisgood
I'm changing my oil pressure line tube from the block to the gauge. Before I hook it to the gauge, do I need to bleed the air out?
Oh ya, one other thing-Card0, you're absolutely wrong and your attitude sucks.
