[W126 Coupe] Engines

[Sharan Bains]

Jim,

I think my original post did say that modifying the  M117 won't give you as 
much as supercharging. That's pretty clear - and David's question was on 
methods of extracting more power without forced induction. We all know 
supercharging gives much more power...you've proved it with your 560....and 
even AMG had to go down that route with the '211 E55. BMW's latest V10 M5 
would crap all over the '210 E55.... AMG's easy solution was to supercharge 
the 5.5 V8.

The fact that the '211 E55 is officially rated at 476hp but you've seen 
dyno's of 500hp is not unusual - MB figs are and always have been 
conservative. And likewise, whilst the new 6.3 is officially rated at 510hp, 
it will likely push out closer to 540hp....5% more than the official 
conservative figure. 0-60's are always conservative too...the '211 e55 has 
an official figure of 4.7 seconds. ...but has got there in 4.2 seconds in 
numerous road tests.

Although wear and tear maybe higher on a high compression engine more of the 
time, it's the risk of detonation with the forced induction engine that is 
the point....doesn't matter if that risk is there for only 2% of the 
time.....it's still a probability of total failure. AMG's '211 E55 no doubt 
has numerous safeguards to lower this probability.

Again, my point on the torque/hp was that torque is far more important than 
hp....too many people focus on hp. Just look at the M119 5.0 litre - pushes 
out 326hp and 332 lbft torque (except the 500E M119 which pushes out 354 
lbft due to revised intake). Now the Euro M117 5.6l manages only 300bhp BUT 
334 lbft torque....more torque than the multivalve M119.

So higher displacement is better to have as you get more torque - and that's 
the more crucial attribute to have....hence my boxing analogy...better to be 
able to punch hard rather than just fast. If you can do both, then great !

My Euro 560 with AMG spec cams, free-flow exhaust , mated to a 722.370 with 
FGS and 2.82 diff,  is furiosuly fast - as fast as my w124 500E....and we 
all know how fast 500E's are. And it's satisfying to get an SEC as fast as a 
500E through engine and driveline upgrades alone. Now if I were to 
supercharge my 560.....whoaaaaaaar...........


Talbir









>From: Jim Nowak <jjnowak_32503 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 15:30:49 -0700 (PDT)
>
>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?
> > So
> > > > is
> > > > > it possible to take a 560 engine from a 91 and
> > > > strip
> > > > > off the the vacuum controls and the mechanical
> > > > fuel
> > > > > injection, basically get down to the bare
> > engine.
> > > > > Then build up the 5.6L to have new fuel
> > > > management,
> > > > > new air intake etc.
> > > > >
> > > > > Also what is the latest MB tranny (year) that
> > you
> > > > > can
> > > > > mate to the M117 engine?  I would think that
> > the
> > > > > later
> > > > > trannys would work better, better gearing and
> > 5
> > > > > total
> > > > > gears too.
> > > > >
> > > > > Any ideas?
> > > > >
> > > > > David
> > > > > The MB Coupes Website!
> > > > > W126 SEC Mailing List
> > > > > Postings remain property of MB Coupes, L.L.C.
> > > > >
> > > >
> > > > The MB Coupes Website!
> > > > W126 SEC Mailing List
> > > > Postings remain property of MB Coupes, L.L.C.
> > > >
> > >
> > >The MB Coupes Website!
> > >W126 SEC Mailing List
> > >Postings remain property of MB Coupes, L.L.C.
> >
> >
> > The MB Coupes Website!
> > W126 SEC Mailing List
> > Postings remain property of MB Coupes, L.L.C.
> >
>
>The MB Coupes Website!
>W126 SEC Mailing List
>Postings remain property of MB Coupes, L.L.C.