--===============9062623537849762949==
Content-Language: en-US
boundary="_000_DM5PR07MB3433D7091CC5BB83F85875F0A5210DM5PR07MB3433namp_"
--_000_DM5PR07MB3433D7091CC5BB83F85875F0A5210DM5PR07MB3433namp_
Content-Transfer-Encoding: quoted-printable
Oil pumps, vane, rotary and gear type are all positive displacement devices=
, meaning that they will continue to build pressure against resistance to t=
he point where something breaks. That is why they are all equipped with a b=
ypass valve which limits the amount of pressure in the system. The amount o=
f stress on the geardtrain is directly proportional to the pressure develop=
ed. I'm not sure if the problems related to the rotary type pumps is a resu=
lt of the stress of driving the pump or to the larger pressure pulses (vibr=
ation) that are inherent in the design.
The manufacturer selects the bypass valve and spring assembly that will kee=
p the pressure within a safe range while protecting the drive system from o=
ver stress. The four cylinder engines are supposed to run at a maximum of 5=
0-55 PSI, the sixes somewhat lower, and it is the bypass valve that maintai=
ns that pressure even though the pump itself is capable of much higher pres=
sures if it encounters excessive resistance.
Viscosity change in the oil when at higher temperatures will reduce pressur=
e by reducing the resistance of the oil circulating through the various cle=
arances in the engine. As the engine wears these clearances will increase t=
hus reducing resistance and dropping oil pressure. Oil pressure alone is no=
t as important as is a constant flow of oil to all components combined with=
the film strength of a good quality oil.
Bill Lawrence
BN1 #554
________________________________
From: Healeys <healeys-bounces@autox.team.net> on behalf of Kees Oudesluijs=
<coudesluijs@chello.nl>
Sent: Wednesday, January 1, 2020 6:37 PM
To: healeys@autox.team.net <healeys@autox.team.net>
Subject: Re: [Healeys] Oil Pumps
Absolutely correct. There may be theoretically a tiny difference,
immeasurable probably, caused by the efficiency of the various pumps.
Kees Oudesluijs
Op 1-1-2020 om 19:24 schreef Bob Spidell:
>
> I'm not a fluid dynamicist, but wouldn't, say, 45psi from either a
> vane/rotor type pump put the same load on the cam gear and driveshaft
> as 45psi from a gear-type pump, all other factors--oil viscosity,
> etc.--being equal? Or, is there some other factor(s) at play? Do the
> gear-type pumps produce lower pressure (seems to me that's the only
> way they'd reduce the load on the gears and the cam thrust plate)?
>
> Bob
_______________________________________________
Archive: http://www.team.net/pipermail/healeys http://autox.team.net/archiv=
e
Healeys@autox.team.net
http://autox.team.net/mailman/listinfo/healeys
sn.com
--_000_DM5PR07MB3433D7091CC5BB83F85875F0A5210DM5PR07MB3433namp_
Content-Transfer-Encoding: quoted-printable
<html>
<head>
<meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3Dus-ascii"=
>
<style type=3D"text/css" style=3D"display:none;"> P {margin-top:0;margin-bo=
ttom:0;} </style>
</head>
<body dir=3D"ltr">
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
Oil pumps, vane, rotary and gear type are all positive displacement devices=
, meaning that they will continue to build pressure against resistance to t=
he point where something breaks. That is why they are all equipped with a b=
ypass valve which limits the amount
of pressure in the system. The amount of stress on the geardtrain is direc=
tly proportional to the pressure developed. I'm not sure if the problems re=
lated to the rotary type pumps is a result of the stress of driving the pum=
p or to the larger pressure pulses
(vibration) that are inherent in the design. </div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
<br>
</div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
The manufacturer selects the bypass valve and spring assembly that will kee=
p the pressure within a safe range while protecting the drive system from o=
ver stress. The four cylinder engines are supposed to run at a maximum of 5=
0-55 PSI, the sixes somewhat lower,
and it is the bypass valve that maintains that pressure even though the pu=
mp itself is capable of much higher pressures if it encounters excessive re=
sistance. </div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
<br>
</div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
Viscosity change in the oil when at higher temperatures will reduce pressur=
e by reducing the resistance of the oil circulating through the various cle=
arances in the engine. As the engine wears these clearances will increase t=
hus reducing resistance and dropping
oil pressure. Oil pressure alone is not as important as is a constant flow=
of oil to all components combined with the film strength of a good quality=
oil. </div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
<br>
</div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
Bill Lawrence</div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
BN1 #554</div>
<div id=3D"appendonsend"></div>
<hr style=3D"display:inline-block;width:98%" tabindex=3D"-1">
<div id=3D"divRplyFwdMsg" dir=3D"ltr"><font face=3D"Calibri, sans-serif" st=
yle=3D"font-size:11pt" color=3D"#000000"><b>From:</b> Healeys <healeys-b=
ounces@autox.team.net> on behalf of Kees Oudesluijs <coudesluijs@chel=
lo.nl><br>
<b>Sent:</b> Wednesday, January 1, 2020 6:37 PM<br>
<b>To:</b> healeys@autox.team.net <healeys@autox.team.net><br>
<b>Subject:</b> Re: [Healeys] Oil Pumps</font>
<div> </div>
</div>
<div class=3D"BodyFragment"><font size=3D"2"><span style=3D"font-size:11pt;=
">
<div class=3D"PlainText">Absolutely correct. There may be theoretically a t=
iny difference,
<br>
immeasurable probably, caused by the efficiency of the various pumps.<br>
<br>
Kees Oudesluijs<br>
<br>
Op 1-1-2020 om 19:24 schreef Bob Spidell:<br>
><br>
> I'm not a fluid dynamicist, but wouldn't, say, 45psi from either a <br=
>
> vane/rotor type pump put the same load on the cam gear and driveshaft =
<br>
> as 45psi from a gear-type pump, all other factors--oil viscosity, <br>
> etc.--being equal? Or, is there some other factor(s) at play?&nb=
sp; Do the <br>
> gear-type pumps produce lower pressure (seems to me that's the only <b=
r>
> way they'd reduce the load on the gears and the cam thrust plate)?<br>
><br>
> Bob<br>
_______________________________________________<br>
m.net/donate.html</a><br>
<br>
Archive: <a href=3D"http://www.team.net/pipermail/healeys";>http://www.team.=
net/pipermail/healeys</a>
<a href=3D"http://autox.team.net/archive";>http://autox.team.net/archive</a>=
<br>
<br>
Healeys@autox.team.net<br>
<a href=3D"http://autox.team.net/mailman/listinfo/healeys";>http://autox.tea=
m.net/mailman/listinfo/healeys</a><br>
<br>
s/ynotink@msn.com">
http://autox.team.net/mailman/options/healeys/ynotink@msn.com</a><br>
<br>
</div>
</span></font></div>
</body>
</html>
--_000_DM5PR07MB3433D7091CC5BB83F85875F0A5210DM5PR07MB3433namp_--
--===============9062623537849762949==
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
_______________________________________________
Archive: http://www.team.net/pipermail/healeys http://autox.team.net/archive
Healeys@autox.team.net
http://autox.team.net/mailman/listinfo/healeys
--===============9062623537849762949==--
|