Home » Public Forums » GMCnet » [GMCnet] High volume oil pumps
| Re: [GMCnet] High volume oil pumps [message #246156 is a reply to message #246154] |
Wed, 02 April 2014 11:03   |
James Hupy
Messages: 6806
Registered: May 2010
Karma:
|
Senior Member |
|
|
Bypass circuits integral with oil pumps do not function at all until system
pressure is the same as or greater than the relief spring. If an engine is
tightly setup that pressure is likely to be achieved more quickly. I am not
talking about cold run conditions here, only fully warmed up.
If rods are drilled with squirt holes or side notched for oil to
escape it allows for more VOLUME to flow before achieving enough pressure
to open the bypass. Net effect here is more splash to the area of the
engine BELOW the piston rings.
If the amount of oil escaping exceeds original oil pump volume, then
logic tells us that a high volume pump has some benefit in oil cooling
cylinder bores and piston bottoms.
Basic tenets apply here and all factors considered, if a given system
has the capability to carry away heat at a faster rate than it is produced
by the engine, it should contribute to longevity of the engine. But you
have to strike a balance. Too cold is just as bad as too hot. "NORMAL
TEMPERATURE RANGE" means one thing in a Nitro methane burning Hemi, quite
another in a grocery getter, and still something else in a low compression
slow speed high piston loaded application like a GMC.
I have great respect for Dick Paterson. He truly understands what it
takes to keep one of these things from self destructing. Remember, it is
not just bolting on a different oilpump, but other tricks in combination
with it that works in concert. Engine builders don't always reveal all
their trick stuff. (grin)
Jim Hupy
Salem, Or.
78 GMC ROYALE 403
On Apr 2, 2014 8:26 AM, "Matt Colie" <matt7323tze@gmail.com> wrote:
>
>
> Jeff Marten wrote on Tue, 01 April 2014 23:18
> > Where does the oil spray originate? Are you inferring filling the pan
> with an excess volume of oil, and thereby using the crank to splash oil
> around??? (terrible idea if so) Or installing spray nozzles so the extra
> volume of oil pumped is utilized?
> > A high volume oil pump does nothing but bypass more oil than a standard
> pump if the bearing clearances aren't set to utilize the extra volume of
> oil. Clearances at X" will only flow X volume of oil, nothing more; the
> additional pump volume will just be bypassed.
>
> Jeff,
>
> I have a leg up on most people. This a direct result of being a refugee
> from engine test laboratories.
>
> The lube oil to cool the piston crowns is thrown up there by the
> connecting rods as they come around. Actually, this is a little bit of a
> misrepresentation. What really happens is the lower end flings oil up
> ward, but it will never reach the piston at top dead center, but that is OK
> because the piston will come right down to get it. It really is kind of
> fun to watch at 1800fps.
>
> If you look at the article Rob referenced, it shows a rod drilled for a
> "piston cooler", but what is also interesting is that they used a rod with
> oil grooves. That is the job those two grooves each side of the rob beam
> are supposed to do. Sometimes rods even have notches in the bearing shell
> to line up with said grooves. The oil hole as pictured will do more to
> lubricate the trust face of the cylinder wall.
>
> Dick Paterson very much understands the higher volume would be little
> value on a standard clearance engine, so he uses the high volume pump, but
> then also sets the engine up "looser" than minimum clearance to take
> advantage of the extra cooling that is then possible.
>
> Matt
> --
> Matt & Mary Colie - Members GMCMI, GMCES home from MontgomeryPlanning
> Chaumière's next excursion
> '73 Glacier 23 With 4 Rear Brakes that pull as they should
> SE Michigan - Twixt A2 and Detroit
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
Current Time: Fri Sep 27 06:34:29 CDT 2024
Total time taken to generate the page: 0.00851 seconds
|
GMCforum
Search
Help
Register
Login
Home
