<VV> STP and the Scerwdriver

[J R Read]

Smitty,

I appreciate that you took the time to answer that question and my feeling 
about "snake oil" salesmen are similar to yours.  Hence my reason for asking 
if this was nothing more than a "parlor trick".  Snake Oil may have been a 
better term.

On the other hand, several folks have responded in a positive fashion on the 
subject of STP.  It sort of sounds like it could be useful as an assembly 
lube - but (to my mind) why take a chance on that when investing the amount 
it takes to do a full rebuild?  For myself, I'm still waiting for empirical 
proof - not merely testimonials - on using it for prolonged engine life as a 
ZDDP additive.  So far, from VV sources, I'm not really convinced and I'm 
beginning to think that I should not have brought up this topic.

Oh... my goal is to be able to decide if Mobil 1 10W30 with appropriate 
amount of STP added will satisfy the ZDDP of 1200 ppm AND provide an 
appropriate viscosity level for Corvair engines within the temp ranges we 
deal with.  I'd ask the racer guys, but I don't think that they are looking 
for the engine longevity that most of us would like.

I'm currently using 15/50 Mobile 1, but sometimes (not often) start and 
drive in cold weather - so wonder if I'm doing damage (on those occasions) 
which could be avoided by a change in what I put into the crankcase.

Later, JR
CCE CORSA CORVANANTICS SCG member
'61 Rampside Standard 4/110
'65 Monza Convertible 4/140
"Keep the Love Alive"

----- Original Message ----- 
From: "Smitty" <vairologist at cox.net>
To: <virtualvairs at corvair.org>
Sent: Wednesday, January 04, 2012 11:00 PM
Subject: <VV> STP and the Scerwdriver


> Smitty Says;  I am not an oil engineer and because of the years since I 
> was
> in the school I am not even sure of the terminology.  Nor am I sure of the
> application.  But here goes.  When I worked for Philips 66 we who were 
> even
> remotely involved in sales had to go to schools on the properties of oils 
> so
> we could sound half smart when talking to customers.  There is a thing
> called dynamic barrier when oil is pumped between flat bearings and
> crankshafts.  It keeps the metals separated when pressure is applied to
> press them together.  If oil too light in viscosity is used the oil will
> extrude out from between the metals and galling will occur.  If oil too
> heavy in viscosity is used the dynamic barrier will rip or pull apart and
> again you will have metal to metal contact.  There is actually a big wide
> range of viscosity that can be satisfactory but naturally the engineers 
> will
> specify a median viscosity to provide protection under high and low heat
> operating conditions.
> STP is a viscosity improver and in it's unmixed state is very thick and
> slick feeling.  Slick, not necessarily because it is such a superior oil ,
> but because at low speeds of relative motion its thickness of barrier
> provides contact prevention between two components.  It might make a heck 
> of
> a lubricant in a differential but in an engine at 7,000 rpm bearing life
> would be very marginal.  The point being that there is a lubricant for 
> every
> application and there is often a fine line between what you can and can 
> not
> get away with.
> Which brings us back to screwdrivers.  When you wet a screwdriver bit with
> STP and then try to hold on to it, chances are you will use the same 
> fingers
> you tried with the conventional oil.  Chances are you will be holding on
> (pinching) just about the same tightness.  The regular oil with a 
> viscosity
> of probably 10 to 40 extruded out from under your fingers and allowed skin
> and fingerprint contact with the screwdriver.  What's the viscosity of 
> STP?
> 100- 120-150?  I don't know but it is going to take a lot longer to 
> squeeze
> it out for the same skin and fingerprint contact you had with the oil.
> Chances are your fingers will get tired and your grip will weaken before
> that happens.  In any event, the holding up a screwdriver with STP in your
> fingers proves absolutely nothing.
> So maybe I am all wet about all this.  I just hate snake oil salesmen
>