Lugging and the effects thereof...

[<ChrisBourk@xxxxxxx>]

<<Date: Mon, 24 Aug 1998 17:39:20 -0400
From: Bruce Augenstein <Bruce.Augenstein@domain.elided>
Subject: Flame Summary: Lugging>>

<<As the pistons stop at the top and bottom of every stroke and move slowly
near TDC and BDC, dropping the engine speed increases the distance the rings
travel with questionable lubrication film formation.  The same logic applies
to the side loads on the pistons, except that these peak halfway through the
stroke.">>

Oh,  and I thought that when you decreased speed you REDUCED the distance
traveled....oh well,  live and learn...

<<Interesting, no?>> so far it's almost enlightening - almost...

<<I think Mr. Fellingham is on to something; namely, that lugging at extremely
low rpm can lead to significantly increased cylinder and ring wear, due to
the low speed of the moving parts at a time when lubrication may be
questionable.>>

But I thought the speed increased under your theory?   Well now I can see it
certainly makes sense to increase speed when the lubricating system is having
trouble - I'd never really thought of it that way...

<<In any event, it is my personal opinion that lugging is extremely bad for
your teeth and jaw muscles (at least it is to mine), and, in fact, may lead
to at least as much cylinder wear as running to red line does. That is to
say, habitual lugging may cause as much "damage" as habitual flat out
driving does. Occasional lugging is probably just as safe as occasional red
lining.>>

Great opinion,  just lacks any support.  Go to ANY race track in the world and
ask when engines blow up, when valves sink, when bearings spin, when rods
snap, when cranks break, when rods pull the piston boss right out of the
botton of the piston, when cams break, when valve springs snap, when balancers
fly off - ask them and you will see it happens at speed.  not when they're
lugging their engine - but when they miss a shift, shift into a lower gear by
accident, have too much boost, make too much power.  My boy this happens at
speed - NOT when they're lugging their engines.

<<On the other hand, even though my 3 liter M3 will pull away smoothly  from a
thousand rpm in fifth (if I'm gentle), it's a bunch happier when it's at
3500 or more, and so am I :-).>>

Hmm,  now thet's science.  An engine being discribed as "happy" 

I did kind of like the idea of the cylinder wear,  problem is it never gave
any numbers or science to back it up - just a hunch and by who?  And all the
people who think your engine dosn't have "metal to metal contact"  NOT,  they
all do,  oil is a step in the right direction but if there was no contact the
wear would be considerably less
Best regards,

Christopher

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