This is a multi-part message in MIME format.
--===============5033119436319338163==
boundary="------------B41D872363332A3C9AE4632E"
Content-Language: en-US
This is a multi-part message in MIME format.
--------------B41D872363332A3C9AE4632E
Content-Transfer-Encoding: 8bit
re: "... delivery pressure itself is not that important and is really
just an indicator that oil is being delivered to the bearings ..."
Pressure is useful as a trend indicator.
On 10/30/2018 8:54 AM, Michael Salter wrote:
> I have a book "Repco Engine Service Manual" produced by Repco of
> Repco-Brabham fame that I use as my bible for engine building.
> On the subject of oil pressure it states that delivery pressure itself
> is not that important and is really just an indicator that oil is
> being delivered to the bearings.
> Of much greater importance is "thin film pressure" which is generated
> by the engine forces on a bearing which can be as high as 8000 p.s.i.
> at high RPM and is determined by the oil type and temperature, and the
> engine design.
> Based upon this I believe that concentrating on having good oil
> pressure at idle is wasted effort. What is important is that the
> engine has some pressure at idle but good pressure in the normal
> operating range.
> A pump which puts out a huge volume uses excessive horsepower and can
> result in accelerated wear of the pump drive.
>
> M
>
>
> On Tue, Oct 30, 2018 at 11:30 AM Bob Spidell <bspidell@comcast.net
>
> I'll offer what I know/have heard*. I have the 'high capacity'
> type in my BJ8, which is what the DWR techs/sales people
> recommended for a road car. Older 6-cyl cars had a rotor type
> pump. They (the rotor type) are supposed to be more
> efficient--i.e. they pump more oil--at lower RPMs. At some point
> it was discovered, probably from service bay repairs, that this
> type of pump put an excessive shear load on the bevel gears on the
> cam that drive the pump, causing them to wear out. Later cars
> started getting the gear type pump, which is less efficient at
> lower RPMs but puts less of a load on the cam, and is probably
> less expensive to manufacture as well (esp. if the gears are the
> sintered iron variety). I think the bevel gears on the cams were
> re-engineered, IIRC they got an additional tooth to spread the load.
>
> The Welch HC pump is the rotor type. I did a full engine rebuild
> and installed the DWR HC pump; I didn't notice any pressure change
> worth mentioning--I 'gained' 15 PSI at idle when I had my gauge
> overhauled--but the 'high capacity' I believe refers to volume
> rather than pressure (which, of course, is mostly dictated by
> engine speed). The 'standard type' pump is a gear type, hence it's
> more appropriate for high-RPM race engines as pump flow is
> proportional to RPM, and at 6K RPM or more you'll get plenty of
> oil with less load from the gear type.
>
> I'm not positive, but if you look at the photos closely, you can
> see the 'gallery plug' on the top of the case. I suppose it
> allows inspection of the innards of the pump without having to
> break the case. I believe it's threaded so not likely to pop
> out. If you're getting a new pump you'll likely need a new drive
> shaft and, surprisingly, DWR sells it cheaper than our (US)
> vendors sell it at (I think they might import the DWR shaft).
>
> * apply appropriate grains of salt
>
> Bob
>
> On 10/30/2018 5:12 AM, simon.lachlan@alexarevel.plus.com
>>
>> Hi,
>>
>> Has anyone got the Denis Welch oil pump ENG672M? See:-
>>
>>
>> https://www.bighealey.co.uk/performance-parts/austin-healey/engines/3000-bottom-end?page=3
>>
>>
>> Their text:- â??Heat treated castings for longer life and
>> removable gallery plugs to be sure it is clean are advantages
>> of both types of oil pumps we offer. We recommend the high
>> capacity for all road engines using a standard type crank up
>> to 6000 rpm and the standard pump for race engines, steel
>> cranks or anything over 6000 rpm. Both are precision machined
>> and assembled in-house to control the highest quality.
>> - ENG672 is the standard type.
>> - ENG672M is the high capacity pump.â??
>>
>> What are â??removable gallery plugsâ???
>>
>> Is it just me or is the above a bit counter-intuitive? â??High
>> capacityâ?? for road cars and â??standardâ?? for race engines? Surely
>> the highest capacity is needed where the engine is working
>> hardest ie racing?
>>
>> And donâ??t I remember that, with the standard BMC pumps, the older
>> type is reckoned to be better than the newer type? Is this
>> something similar to Denis Welchâ??s two pumps?
>>
>> Anyhow, if anyoneâ??s got oneâ?¦..whatâ??s it like? Did the oil
>> pressure improve at all?
>>
>> Iâ??m guessing that most people will have fitted one as part of a
>> big rebuild thus they wonâ??t have straightforward â??before and
>> afterâ?? comparisons. Iâ??m thinking of fitting mine to my engine as
>> part of a small winter project and hope I can squeeze a few more
>> psi into the system.
>>
>> Thanks,
>>
>> Simon
>>
>>
>>
>> _______________________________________________
>> Support Team.Nethttp://www.team.net/donate.html
>> Suggested annual donation $12.75
>>
>> Archive:http://www.team.net/pipermail/healeys
>> http://autox.team.net/archive
>>
>> http://autox.team.net/mailman/listinfo/healeys
>>
>>
>> Unsubscribe/Manage:http://autox.team.net/mailman/options/healeys/bspidell@comcast.net
>>
>
> _______________________________________________
> Support Team.Net http://www.team.net/donate.html
> Suggested annual donation $12.75
>
> Archive: http://www.team.net/pipermail/healeys
> http://autox.team.net/archive
>
> http://autox.team.net/mailman/listinfo/healeys
>
> Unsubscribe/Manage:
> http://autox.team.net/mailman/options/healeys/michaelsalter@gmail.com
>
--------------B41D872363332A3C9AE4632E
Content-Transfer-Encoding: 8bit
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<p>re: "... delivery pressure itself is not that important and is
really just an indicator that oil is being delivered to the
bearings ..."</p>
<p>Pressure is useful as a trend indicator.<br>
</p>
<br>
<div class="moz-cite-prefix">On 10/30/2018 8:54 AM, Michael Salter
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAB3i7LK1diV=imAHBzxBj6tL06YDF9G7LOEd=JwRL3zT-eT21g@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<div dir="ltr">
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:small">I have a book "Repco Engine
Service Manual" produced by Repco of Repco-Brabham fame that I
use as my bible for engine building. <br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:small">On the subject of oil pressure
it states that delivery pressure itself is not that important
and is really just an indicator that oil is being delivered to
the bearings. <br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:small">Of much greater importance is
"thin film pressure" which is generated by the engine forces
on a bearing which can be as high as 8000 p.s.i. at high RPM
and is determined by the oil type and temperature, and the
engine design.</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:small">Based upon this I believe that
concentrating on having good oil pressure at idle is wasted
effort. What is important is that the engine has some pressure
at idle but good pressure in the normal operating range. <br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:small">A pump which puts out a huge
volume uses excessive horsepower and can result in accelerated
wear of the pump drive.</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:small"><br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:small">M<br>
</div>
<div class="gmail_default" style="font-family:comic sans
ms,sans-serif;font-size:small"><br>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr">On Tue, Oct 30, 2018 at 11:30 AM Bob Spidell <<a
href="mailto:bspidell@comcast.net";
moz-do-not-send="true">bspidell@comcast.net</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<p>I'll offer what I know/have heard*. I have the 'high
capacity' type in my BJ8, which is what the DWR
techs/sales people recommended for a road car. Older
6-cyl cars had a rotor type pump. They (the rotor type)
are supposed to be more efficient--i.e. they pump more
oil--at lower RPMs. At some point it was discovered,
probably from service bay repairs, that this type of pump
put an excessive shear load on the bevel gears on the cam
that drive the pump, causing them to wear out. Later cars
started getting the gear type pump, which is less
efficient at lower RPMs but puts less of a load on the
cam, and is probably less expensive to manufacture as well
(esp. if the gears are the sintered iron variety). I
think the bevel gears on the cams were re-engineered, IIRC
they got an additional tooth to spread the load.<br>
</p>
<p>The Welch HC pump is the rotor type. I did a full engine
rebuild and installed the DWR HC pump; I didn't notice any
pressure change worth mentioning--I 'gained' 15 PSI at
idle when I had my gauge overhauled--but the 'high
capacity' I believe refers to volume rather than pressure
(which, of course, is mostly dictated by engine speed). Â
The 'standard type' pump is a gear type, hence it's more
appropriate for high-RPM race engines as pump flow is
proportional to RPM, and at 6K RPM or more you'll get
plenty of oil with less load from the gear type.</p>
<p>I'm not positive, but if you look at the photos closely,
you can see the 'gallery plug' on the top of the case. I
suppose it allows inspection of the innards of the pump
without having to break the case. I believe it's threaded
so not likely to pop out. If you're getting a new pump
you'll likely need a new drive shaft and, surprisingly,
DWR sells it cheaper than our (US) vendors sell it at (I
think they might import the DWR shaft).<br>
</p>
* apply appropriate grains of salt<br>
<br>
Bob<br>
<br>
<div class="m_-555035641554905656moz-cite-prefix">On
10/30/2018 5:12 AM, <a
class="m_-555035641554905656moz-txt-link-abbreviated"
href="mailto:simon.lachlan@alexarevel.plus.com";
target="_blank"
moz-do-not-send="true">simon.lachlan@alexarevel.plus.com</a>
wrote:<br>
</div>
<blockquote type="cite">
<div class="m_-555035641554905656WordSection1">
<p class="MsoNormal">Hi,</p>
<p class="MsoNormal">Has anyone got the Denis Welch oil
pump ENG672M? See:-</p>
<p class="MsoNormal"><a
href="https://www.bighealey.co.uk/performance-parts/austin-healey/engines/3000-bottom-end?page=3";
target="_blank"
moz-do-not-send="true">https://www.bighealey.co.uk/performance-parts/austin-healey/engines/3000-bottom-end?page=3</a></p>
<h2
style="margin-right:0cm;margin-bottom:6.0pt;margin-left:0cm;line-height:20.25pt">Their
text:- â??<span
style="font-size:9.0pt;font-family:"Arial",sans-serif;color:#555555">Heat
treated castings for longer life and removable
gallery plugs to be sure it is clean are advantages
of both types of oil pumps we offer. We recommend
the high capacity for all road engines using a
standard type crank up to 6000 rpm and the standard
pump for race engines, steel cranks or anything over
6000 rpm. Both are precision machined and assembled
in-house to control the highest quality.<br>
</span><span
style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#555555">-
ENG672 is the standard type.</span><span
style="font-size:9.0pt;font-family:"Arial",sans-serif;color:#555555"><br>
- ENG672M is the high capacity pump.â??</span></h2>
<p class="MsoNormal"
style="margin-bottom:12.75pt;line-height:14.4pt"><span
style="font-size:9.0pt;font-family:"Arial",sans-serif;color:#555555">What
are â??removable gallery plugsâ???</span></p>
<p class="MsoNormal"
style="margin-bottom:12.75pt;line-height:14.4pt"><span
style="font-size:9.0pt;font-family:"Arial",sans-serif;color:#555555">Is
it just me or is the above a bit counter-intuitive?
â??High capacityâ?? for road cars and â??standardâ?? for
race engines? Surely the highest capacity is needed
where the engine is working hardest ie racing? </span></p>
<p class="MsoNormal"
style="margin-bottom:12.75pt;line-height:14.4pt"><span
style="font-size:9.0pt;font-family:"Arial",sans-serif;color:#555555">And
donâ??t I remember that, with the standard BMC pumps,
the older type is reckoned to be better than the
newer type? Is this something similar to Denis
Welchâ??s two pumps?</span></p>
<p class="MsoNormal"
style="margin-bottom:12.75pt;line-height:14.4pt"><span
style="font-size:9.0pt;font-family:"Arial",sans-serif;color:#555555">Anyhow,
if anyoneâ??s got oneâ?¦..whatâ??s it like? Did the oil
pressure improve at all?</span></p>
<p class="MsoNormal"
style="margin-bottom:12.75pt;line-height:14.4pt"><span
style="font-size:9.0pt;font-family:"Arial",sans-serif;color:#555555">Iâ??m
guessing that most people will have fitted one as
part of a big rebuild thus they wonâ??t have
straightforward â??before and afterâ?? comparisons. Iâ??m
thinking of fitting mine to my engine as part of a
small winter project and hope I can squeeze a few
more psi into the system. </span></p>
<p class="MsoNormal">Thanks,</p>
<p class="MsoNormal">Simon</p>
</div>
<br>
<fieldset
class="m_-555035641554905656mimeAttachmentHeader"></fieldset>
<br>
<pre>_______________________________________________
Archive: <a class="m_-555035641554905656moz-txt-link-freetext"
href="http://www.team.net/pipermail/healeys"; target="_blank"
moz-do-not-send="true">http://www.team.net/pipermail/healeys</a> <a
class="m_-555035641554905656moz-txt-link-freetext"
href="http://autox.team.net/archive"; target="_blank"
moz-do-not-send="true">http://autox.team.net/archive</a>
<a class="m_-555035641554905656moz-txt-link-abbreviated"
href="mailto:Healeys@autox.team.net"; target="_blank"
moz-do-not-send="true">Healeys@autox.team.net</a>
<a class="m_-555035641554905656moz-txt-link-freetext"
href="http://autox.team.net/mailman/listinfo/healeys"; target="_blank"
moz-do-not-send="true">http://autox.team.net/mailman/listinfo/healeys</a>
</pre>
</blockquote>
<br>
</div>
_______________________________________________<br>
Support Team.Net <a href="http://www.team.net/donate.html";
rel="noreferrer" target="_blank"
moz-do-not-send="true">http://www.team.net/donate.html</a><br>
Suggested annual donation $12.75<br>
<br>
Archive: <a href="http://www.team.net/pipermail/healeys";
rel="noreferrer" target="_blank"
moz-do-not-send="true">http://www.team.net/pipermail/healeys</a>
<a href="http://autox.team.net/archive"; rel="noreferrer"
target="_blank"
moz-do-not-send="true">http://autox.team.net/archive</a><br>
<br>
<a href="mailto:Healeys@autox.team.net"; target="_blank"
moz-do-not-send="true">Healeys@autox.team.net</a><br>
<a href="http://autox.team.net/mailman/listinfo/healeys";
rel="noreferrer" target="_blank"
moz-do-not-send="true">http://autox.team.net/mailman/listinfo/healeys</a><br>
<br>
Unsubscribe/Manage: <a
href="http://autox.team.net/mailman/options/healeys/michaelsalter@gmail.com";
rel="noreferrer" target="_blank"
moz-do-not-send="true">http://autox.team.net/mailman/options/healeys/michaelsalter@gmail.com</a><br>
<br>
</blockquote>
</div>
</blockquote>
<br>
</body>
</html>
--------------B41D872363332A3C9AE4632E--
--===============5033119436319338163==
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
--===============5033119436319338163==--
|