Craig has a good point. You can increase volume to a point and not increase
pressure as long as bypass valve can handle it. In my case, on my old
Mustang, I went overboard on the oil pump to the point that the bypass valve
could not handle the increased flow. As a result, I had excessive pressure.
I not sure if there is an oil pump made for the 1500 that can cause this. I
am thinking the person who responded earlier boasting of 90 psi might have
had a stiffer spring or a lot of shims in his bypass valve.
Larry, I guess by now you are realizing that the concensus is that the stock
pump will do just fine. In fact, when I rebuilt my 1500 I checked the
clearances and reused the old pump. It works just fine.
Max
>From: Carter Shore <clshore@yahoo.com>
>To: Craig Smith <CraigS@iewc.com>, 'Max Brewster' <brewsjl@hotmail.com>,
>sos@kymtnnet.org, spitfires@autox.team.net
>Subject: RE: High Volume Oil Pump
>Date: Wed, 10 Jan 2001 05:47:21 -0800 (PST)
>
>SpitListers,
>remember that the Spitfire has an oil pressure bypass
>valve built into it. ISTR 70 psi is the spec.
>Except for the pumping power losses, there should be
>no problem with excess pressure.
>
>There is a procedure mentioned in the Factory Shop
>Manual for adjusting pressure with shims, and the Comp
>manual suggests lapping the bypass valve/seat assembly
>to get a good seal.
>
>Though I have built many Spifire motors, both stock
>and comp, I have never performed this procedure.
>
>I do plan to pay close attention and do this when I
>build the bottom end of my turbo 1500. The turbo needs
>additional oil, so I want to use a GT6 pump.
>
>Carter Shore
>
>--- Craig Smith <CraigS@iewc.com> wrote:
> >
> > High volume is relative.
> >
> > My rebuilt 71 runs 75 cold and 20 hot.
> > High volume is relative.
> > At 7,500 RPM 20 PSI is still a positive.
> > What do you need ?
> > A reading of any kind is usually taken from right
> > off the pump below the
> > dizzy.
> >
> > 20 PSI @ 10,000 RPM or 20 PSI @ 7,500 RPM
> > Same thing
> >
> > More PSI doesn't equate to squat
> >
> > There is a foaming quotient at high RPM, but I don't
> > think ANY Triumph has
> > to worry about that !
> >
> >
> > -----Original Message-----
> > From: Max Brewster [mailto:brewsjl@hotmail.com]
> > Sent: Tuesday, January 09, 2001 10:49 PM
> > To: sos@kymtnnet.org; spitfires@autox.team.net
> > Subject: Re: High Volume Oil Pump
> >
> >
> >
> > Larry, I rebuilt my 79 1500 last spring with a stock
> > pump. 75 psi cold, 45
> > psi hot at speed, and 20 psi at idle when hot. This
> > is plenty of oil
> > pressure. Be careful with too high a psi you could
> > blow out oil filters
> > unless you can get high pressure one. I don't know
> > if they are available for
> >
> > the 1500. You can also stress the oil pump drive
> > shaft,
> > although the 1500 shaft is pretty hefty. If you go
> > with a high volume pump,
> > let your engine warm up for a while before getting
> > on it. I ran across the
> > filter problem on my 68 Mustang with a high volume
> > pump. It pegged my 100
> > psi oil pressure gage when cold and I did blow out a
> > stock filter. It came
> > apart at the seams!! The high pressure filter fixed
> > this problem.
> >
> > Good Luck,
> > Max Brewster
> > 79 Spitfire 1500
> >
> >
> > >From: Larry Elswick <sos@kymtnnet.org>
> > >Reply-To: Larry Elswick <sos@kymtnnet.org>
> > >To: Spitfires mailing list
> > <spitfires@autox.team.net>
> > >Subject: High Volume Oil Pump
> > >Date: Mon, 08 Jan 2001 14:43:47 -0500
> > >
> > >I'm just about ready to start re-assembly of
> > >my 1500 engine. I was told a high volume oil
> > >pump isn't really necessary. I had the center
> > >oil gallery drilled out to 5/16" . How about
> > >some opinions. Thanks!
> > >Larry
> >
> >
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