oil pumps (not efi)

[Frank Mallory]

tom cloud wrote:
 
> I've gotta make a decision soon.  My mentor and the part$ guy at
> the Ford haus advise me to put a high volume oil pump in my new
> hi performance SVO engine.  Dumb me, I gotta ask WHY??  (I've just
> purchased a "Lightning" short block from Ford SVO.)
> 
> The high volume pump does not increase pressure, so no more oil
> flows through the engine than for a normal pump, unless there's
> a loose fitting or such, right?
> 
It wouldn't increase the _maximum_ pressure, which is governed my a
relief valve; but it should increase the _average_ pressure, which is
tha pressure at which most engines run at lower speeds after the oil get
hot. And the oil in a HO engine would probably run hotter than in a
standard engine.

> Here's what I have found:
> 
>  - same volume of oil will be pumped by stock and hi-vol pump (i.e.
> hi-vol pump will just recirculate and 'froth' the oil).  The only
> time the hi-vol capability will be needed is when the engine is
> very old or has an internal 'leak'.
> 

Why do they call it "high volume" if it pumps the same volume of oil?

>  - you are advised to buy a hardened, stronger oil pump drive shaft
> when you get a hi-vol pump ...... this implies to me that there's
> more of a load on the shaft, hence on the cam gears, on the cam 'bearings',
> on the timing chain and gears.  Why would you do that?
> 

I can't answer that, but it seems like good advice.

>  - my 302 in my F150 with 107,918 (as of this morning) reads very near
> the same oil pressure it did when it was new (on the "A" of "NORMAL",
> heh-heh).  It does this even when hot, down a quart and at idle of
> 650 rpm (once again, as of this morn).
> 

This is an easy one. The oil pressure "gauge" on your F150 is a dummy.
No, I don't mean it's not very smart -- it is actually a phony "gauge"
that doesn't tell you anything except that the engine is running.

> This reminds me of myself going to the part$ hou$e to buy 'lifetime'
> shocks that are "better than stock" (same deal with brake pads) after
> putting 100,000 miles on the original set!!   WHAT'S THE POINT ???
> 
> Help me, Rhonda!
> 
> Neither my mentor/guru nor my part$ guru could tell me why I should
> use a high volume pump.  Seems to me to really just be a waste of
> _precious_ horsepower and a source of unnecessary wear on the cam
> and related components.
> 
> Help
> 
I think it depends to a large extent what kind of use you are going to
put your modified engine to. If you intend to pull a trailer, enter long
distance races or hillclimbs, or otherwise extract a large percent of
available HP from your engine, a HD oil pump is probably a good idea;
otherwise, not.