[W126 Coupe] Engines

[David Fatovic]

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>
> > >To: Mercedes Coupes Mailing Lists
> > <mbcoupes at mbcoupes.com>
> > >Subject: Re: [W126 Coupe] Engines
> > >Date: Mon, 18 Jul 2005 10:26:12 -0700 (PDT)
> > >
> > >So once you strip off all the control stuff, you
> > have
> > >an engine to do whatever you want with it
> correct?
> > >Somewhat?  I feel you can get much more
> horsepower
> > out
> > >of the engine other ways than supercharging it.
> > >
> > >Thanks,
> > >
> > >David
> > >
> > >--- Jim Nowak <jjnowak_32503 at yahoo.com> wrote:
> > >
> > > > David, that is correct.  I'm looking to do
> that
> > to
> > > > my
> > > > SEC and I already did it to my porsche 928.
> > > >
> > > > Jim
> > > >
> > > > --- David Fatovic <coloradocroat at yahoo.com>
> > wrote:
> > > >
> > > > > I have a question.  An engine is an engine
> is
> > an
> > > > > engine once you strip off the controls
> right? 
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