[Shotimes] rod bearings

[Paul Nimz]

>The definition, for this purpose of "lugging" is running the
>motor at extremely low rpm (generally, for any motor,
>between idle and about 1200 to 1500 rpm) and LARGE throttle
>openings!

I use to drive a Mack 18 wheeler back in the day, that had a redline of 1500
rpm and a 5 speed tranny to boot.  Thing would really haul the coal and it
was nice not having to shift all them gears....

Paul Nimz
'97 TR
'93 EG mtx



----- Original Message ----- 
From: "Donald Mallinson" <dmall@mwonline.net>
To: <shotimes@autox.team.net>
Sent: Wednesday, August 13, 2003 5:49 PM
Subject: Re: [Shotimes] rod bearings


> Jim,
>
> I don't think anybody (especially me) said that running a
> motor (including the SHO) at or below 2000 rpm is "lugging".
>
> The definition, for this purpose of "lugging" is running the
> motor at extremely low rpm (generally, for any motor,
> between idle and about 1200 to 1500 rpm) and LARGE throttle
> openings!
>
> Big difference between just cruising at 1500 rpm and trying
> to accelerate at full throttle at 1500 or less rpm.
>
> When the motor starts bucking and has that rough rumble at
> low rpm's and big throttle openings, you are going to do
> damage that would not be there if you were at a higher and
> more normal rpm setting.
>
> NO manufacturer I know will advise running a motor like
> this.  And it applies only to Manual trans motors.  Yes, you
> can get SOME throttle application with an ATX if working
> right, but not much, and that is the big difference.
>
> Don Mallinson
>
> Jim and Debbie Leyden wrote:
> > I concur, lugging a car engine doesn't do anything to damage the
bearings.
> > One of the points that I have disagreed on that is popular on the list
is
> > that you shouldn't run it under 2000 RPM.  Heck, 2000 RPM in 5th is
barely
> > 55 MPH.  I can't believe that they would design a car that was "lugging"
at
> > what the maximum posted speed limit was in those days.
> >
> > Jim
> > '93 MTX
> > replaced rings and bearings at 200K
> >
> >
> >
> > -----Original Message-----
> > From: shotimes-admin@autox.team.net
> > [mailto:shotimes-admin@autox.team.net]On Behalf Of John Weidenbenner
> > Sent: Wednesday, August 13, 2003 10:34 AM
> > To: 'David Schultz'; shotimes@autox.team.net
> > Subject: Re: [Shotimes] rod bearings
> >
> >
> > The 3.2 oil pump capacity is 25% greater than the 3.0 pump. This has to
be a
> > major reason why the 3.0 is so hard on rod bearings. Not everyone
believes
> > that lugging the engine kills the rod bearings. Lugging the engine on a
worn
> > engine will sometimes make the oil pressure light flicker at near stall
> > speed, but that's just showing you the condition of the lubrication
system.
> > I believe its just an old wives tail. Anyone have any real proof?
> >
> > Sometimes just rod bearing replacement will increase the oil pressure
> > enough. To do it right replace the rod & main bearings and the oil pump.
> >
> > John W.
> >
> >
> >
> > Subject: RE: [Shotimes] rod bearings
> >
> >
> >
> >>Yeah, the rod bearings on my '95 were trashed at 86K miles. See Rod
> >
> > Bearing
> >
> >>Job:
> >>
> >> http://www.picturetrail.com/gallery/view?username=rsporter
> >>
> >>But, this was an MTX.
> >>
> >>One of our suspicions is that MTXs can have more wear if the engine was
> >>lugged around, with poor maintenance playing a lesser role.
> >>
> >>Now, you are doing a 3.2, which I assume has spent it's life in front of
a
> >>ATX. What did the rest of the engine look like? Was the oil ever changed
> >
> > in
> >
> >>90K+ miles??
> >>
> >>Ron Porter
> >>
> >>-----Original Message-----
> >>From: shotimes-admin@autox.team.net
[mailto:shotimes-admin@autox.team.net]
> >>On Behalf Of David Schultz
> >>Sent: Tuesday, August 12, 2003 1:18 PM
> >>To: shotimes@autox.team.net
> >>Subject: RE: [Shotimes] rod bearings
> >>
> >>
> >>This is true.  I am in the process of rebuilding a 3.2l, and have
replaced
> >>the main and rod bearings.  Where as the rods had considerable, but even
> >>wear, the main bearings had considerably less visible signs of wear and
> >>probably didn't need replacing.  The rod berings however, did not have
> >
> > much
> >
> >>life left in them.  This on an engine '94 engine with 90,xxx miles on
it.
> >>
> >>Dave
> >>
> >>
> >>>I see it as the other way around. Rod bearings, by design, take more
> >>>punishment and are more susceptible to failure. Mains have a rather
easy
> >>>life (relatively speaking). I see the loss of oil pressure due to wear
on
> >>>rod bearings.
> >>>
> >>>Ron Porter
> >>
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