[W126 Coupe] Engines

[Jim Nowak]

Milling the heads for greater CR or adding a thicker
head gasket for a lower CR.

"efficeince rate from"  Man, I've got to start using
spell checker.  I butchered efficiency in that
sentence.


Jim 


--- David Fatovic <coloradocroat at yahoo.com> wrote:

> Speaking of compression, I know that changing
> pistons
> and rings, you can change compression.  What are
> other
> ways to change compression?  More on the top end of
> the engine?
> 
> David
> 
> --- Jim Nowak <jjnowak_32503 at yahoo.com> wrote:
> 
> > Talbir,
> > 
> > "Yes, absolutely, you can extract plenty of power
> > without supercharging!"
> > 
> > No where near what you can get from a
> supercharger. 
> > With forced induction you can achieve over 100%
> > efficeince rate from an engine.  There is no
> > comparison with power returns per dollar spent on
> a
> > forced induction motor vs a NA motor.   
> > 
> > "NORMALLY aspirated V8 and shoves out 510hp and
> more
> > importantly 630 NM of torque !!!!"
> >   
> > I hear what you are saying.  However, the AMG 5.5L
> > supercharged motor already has much more torque at
> > 700
> > NM and just about as much hp as the 6.3 L.  The
> > factory rates the E55 hp at 476 but it is more
> like
> > 500+ from the dynos I've seen.   Not to mention,
> the
> > supercharged 5.5L motor is easily modified for 550
> > to
> > 600 + hp and can take the E55 AMG to the 1/4 mile
> in
> > the low 11 second range.  The 6.3L engine will be
> > very
> > difficult to modify and will be twice as expensive
> > to
> > extract the same amout of power as the   blown
> 5.5L.
> >  
> > 
> > The only real positive I see from the 6.3L motor
> is
> > the displacement and weight savings.  You can swap
> > the
> > piston for lower CR and boost away.  There is no
> > replacement for displacement.  Of course, given
> > every
> > thing else is equal. 
> > 
> > "But if you're prepared to get involved, then get
> > down
> > to the bare M117 and work from there...higher lift
> > cams, revised pistons, unpgraded injection and
> > ignition control systems, revise the exhaust
> > manifolds
> > etc etc...you'll have a super engine with plenty
> of
> > power. And one that will have longevity, smoother
> > and
> > more responsive, without the detonation risk that
> a
> > forced induction engine carries."
> > 
> > The supercharged street motor will be more
> reliable
> > given the same fuel and ignition changes.  A
> > supercharged street motor is only under boost for
> > possibly 2% of the time.  For the remainder of the
> > time, that engine has much less wear and tear than
> a
> > similar high compression motor.  A high
> compression
> > motor is always under that same stress but the
> blown
> > motor gets a break when you are not at WOT. 
> >  
> > "If you compare to boxing, bhp is about how FAST
> you
> > can punch...torque is about how HARD you can punch
> > !"
> > 
> > HP is a measure of torque.  HP = torque * RPM/5252
> 
> > You can't have hp without torque and rpm.  If you
> > keep
> > the torque higher in the rpm band, you will have
> > more
> > power.  It's rather simple.  
> > 
> > "Do the Aussie spec SEC's have an even lower
> > compression ratio of 8:1 ? They'd be PERFECT for
> > turbocharging, provided an intercooler is worked
> > into
> > the process."
> > 
> > I'm not sure but the US motor is just about
> perfect
> > at
> > 9:1 CR for supercharging.
> > 
> > 
> > Jim  
> > 
> >  
> > 
> > 
> > --- Sharan Bains <sharanbains at hotmail.com> wrote:
> > 
> > > Yes, absolutely, you can extract plenty of power
> > > without supercharging !
> > > 
> > > Just look at the latest engine released by
> AMG....
> > > 6.2 litre (labelled 6.3) 
> > > NORMALLY aspirated V8 and shoves out 510hp and
> > more
> > > importantly 630 NM of 
> > > torque !!!! And that's the most crucial
> statistic,
> > > torque. If you compare to 
> > > boxing, bhp is about how FAST you can
> > punch...torque
> > > is about how HARD you 
> > > can punch !
> > > 
> > > Now the 5.6 isn't too far off in terms of
> > > displacement - the increased 
> > > displacement mainly provides more torque.
> > > 
> > > This latest engine gets it's massive power from
> a
> > > high compression ratio of  
> > > 11.3:1....that's almost like having a US spec
> 9:1
> > > compression 5.6 M117 
> > > running at 10 psi boost ! And then the
> > sophisticated
> > > fuel and ignition 
> > > control units maximise the power further.
> > > 
> > > Supercharging is fine and works well if you
> don't
> > > want to get technical and 
> > > want easy bolt on power. And the power gains are
> > > big....more than you'd gain 
> > > from a normally aspirated M117.
> > > 
> > > But if you're prepared to get involved, then get
> > > down to the bare M117 and 
> > > work from there...higher lift cams, revised
> > pistons,
> > > unpgraded injection and 
> > > ignition control systems, revise the exhaust
> > > manifolds etc etc...you'll have 
> > > a super engine with plenty of power. And one
> that
> > > will have longevity, 
> > > smoother and more responsive, without the
> > detonation
> > > risk that a forced 
> > > induction engine carries.
> > > 
> > > All I did with my Euro 560 was change the
> > camshafts
> > > to AMG spec ones - and 
> > > the performance increase was very significant.
> I'd
> > > say in the 20-30hp range, 
> > > with ease....and those cams do make a real
> > > difference in the Euro engines. I 
> > > fI ever find a set of AMG spec pistons, I'll be
> > well
> > > chuffed ....
> > > 
> > > Do the Aussie spec SEC's have an even lower
> > > compression ratio of 8:1 ? 
> > > They'd be PERFECT for turbocharging, provided an
> > > intercooler is worked into 
> > > the process.
> > > 
> > > 
> > > talbir
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > >From: David Fatovic <coloradocroat at yahoo.com>
> > > >Reply-To: Mercedes Coupes Mailing Lists
> > > <mbcoupes at mbcoupes.com>
> 
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