[Shotimes] Engine Vacuum

[Paul Nimz]

Yes I don't defeat the PCV system.  I only stop the air from coming in.
There still is blowby and this will be drawn out by the vacuum.  There is
just much less water vapor and actual blowby on a healthy engine when the
crankcase is under a vacuum.  And the lighter, more volatile contaminates
will quickly be boiled off and exhausted from the crankcase.

The V6 all I can get is around 2" with the venturi type vacuum generation in
the TB.  On the V8 with the normal PCV valve I can get near 10" at cruising
speeds.  I tried to connect a typical PCV valve to my V6 motor once but got
quite a bit of whistling through the TB.  Probably from one of the three PCV
venturi ports.

Paul Nimz
'97 TR
'93 EG mtx


----- Original Message ----- 
From: "Robert Bruce" <rbruce@bellatlantic.net>
To: <shotimes@autox.team.net>
Sent: Saturday, June 19, 2004 3:01 PM
Subject: RE: [Shotimes] Engine Vacuum


> I wouldn't want to defeat the PCV system.  That could lead to engine leaks
> at the f & r main seals, valve covers, cam seals, plug well gaskets, etc.
> You need you maintain a vacuum on the crankcase in order for the main
seals
> and cam seals to work properly.
>
> A fluid separator in the PCV system would be beneficial.  It helps reduce
> the varnish buildup in the intake that is common with the SHOs.  Paul Nimz
> and I both run versions of a separator.  Maybe a few others use it as
well.
>
> Actually a high vacuum in the crankcase increases hp a couple of ways.
Oil
> droplets and mist can't stay suspended in the air of the crankcase under
the
> high vacuum conditions.  Therefore the oil tends to fall off the rods and
> crank, then drain back to the pan quickly.  If there is less oil sticking
to
> the rods and crank, then there is now less rotating weight.  The second
way
> a high vacuum helps is it's effect on helping the piston rings seals
better
> under heavy loads.
>
> Robert Bruce
> 93 atx street
> 92 track
>
>
> -----Original Message-----
> From: shotimes-admin@autox.team.net
> [mailto:shotimes-admin@autox.team.net]On Behalf Of Carl Prochilo
> Sent: Saturday, June 19, 2004 1:53 PM
> To: shotimes@autox.team.net
> Subject: [Shotimes] Engine Vacuum
>
>
> Why is this subject important?  Looking for a primer type dissertation.
> I've already heard that the PCV system should be defeated...
> --
> Thanks and Cheers,
> Carl Prochilo
> 92 Ultra Red Crimson
>
> On Sat, June 19, 2004 1:41 pm, Alan Fanning said:
> > FWIW, I recently tested several SHO's for engine vacuum at a group
> > get-together. I saw a steady 25 inches as a typical reading on a stock
> > SHO.
> > On my engine with Stage 1 cams I was down to about 15 inches, but still
> > steady.  If the needle is flopping all over you have problems, but I
don;t
> > recall the details.
> >
> >     Alan
> >
> >> From: "Kevin & Cheryl Airth" <clubairth@peoplepc.com>
> >> To: "Paul Nimz" <pnimz@v8sho.com>, <cmichaelo@optonline.net>
> >> Cc: "shotimes" <shotimes@autox.team.net>
> >> Subject: Re: RE: [Shotimes] What can destroy a cat?
> >> Date: Sat, 19 Jun 2004 12:12:21 -0500
> >>
> >> Thanks Paul!!
> >> I had forgot about using a vacuum gauge. Here is why. Have you
attempted
> >> this? I have found the vacuum gauge and it's actions are so wide open
to
> >> interpretation that everyone who looked at the readings came up with a
> >> different answer!! I think vacuum tests would be more useful if we
could
> >> some how get a baseline for each engine. Maybe with 2 SHO's side by
side
> >> and
> >> using the same gauge and the same tests. That might give you a leg up
on
> >> what is actually happening inside the engine. You do mention something
> >> that
> >> may have messed up my experiences. My vacuum gauge does NOT have the
> >> gauge
> >> damper control. I have not seen one with it? Maybe my gauge is a cheap
> >> one
> >> but the damper adjustment would put another variable in the system that
> >> has
> >> too many already?
> >> .
> >> .
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