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From: ? on 28 May 2010 08:41
On May 27, 11:39 pm, "TMack"
<tonyREMOVECAPSmac...(a)REMOVECAPS.dsl.pipex.com> wrote:
> Stock the S40 gives 28-29 bhp at he back wheel.  With performance exhaust,
> air filter and carburettor tweaks it can get up to around 33bhp.  With
> maximum conventional tuning (which would add enlarged and polished ports,
> performance cam etc) it might get up to around 40 bhp.  The only way you
> could get 50 bhp out of that engine would be with maximum conventional
> tuning PLUS nitrous oxide and/or supercharger.

The S40's peak power occurs at 5400 RPM.

Horsepower production is based upon increasing the peak RPM the engine
turns,
if volumetric efficiency (cylinder filling) does not improve.
Simplistically,
if you want to extract 60 horsepower from the Savage engine, all you
have to do is double the engine
RPM to 10800 RPM.

But, who ever heard of twisting a big single up that high? My
counterbalanced
short stroke KLR600 will rev up to around 8000 RPM, but piston rocking
of the 100mm piston
causes it to use a quart of oil every 500 miles.

The Savage is counterbalanced too, but it's a square engine (i.e., the
bore
and stroke are the same).

Bore and Stroke: 94.0 mm x 94.0 mm (3.7 in X 3.7 in)

Power and torque output: 30 hp @ 5400 rpm, 33.5 foot pounds @3400
rpm.

Horsepower = Torque X RPM divided by 5252. If the engine still makes
33.5
foot pounds of torque at 5400 RPM, it makes 34.4 horsepower.

Piston speed at 5400 rpm = 0.166 X 3.7 X 5400 = 3317 feet per minute

It would probably be safe to operate the Savage engine at 7400 RPM
where it would produce 47 horsepower.

The piston speed would be 4545 feet per minute.

This would be a relatively safe piston speed to avoid ring flutter,
but the
mechanical stress on the moving parts would almost double.

Stress = ( 7400/5400 ) squared = 1.88

There is probably somebody out there in AMA Short Track land who loves
Savage
engines and has a high compression, re-cammed Savage engine in a
custom flat
track frame.

I don't think a cruiser rider would want to go so far, but 47
horsepower in a
350 pound cruiser sounds like it's quite adequate. It would be loud,
with a
megaphone exhaust and open air intake and re-jetted carburetor and the
rider
would have to keep the engine in the right gear all the time.

Finding different pulleys and a longer drive belt to re-gear a souped
up
Savage might be difficult.

This is how you can experimentally determine how the horsepower
delivery of
the Savage engine would feel, without buying an aftermarket camshaft.

http://www.bikebandit.com/partsbandit/showschematic.asp?dept_id=2412069

Turn the engine to TDC on the compression stroke. Remove the camshaft.
Slot
the bolt holes in item #2 sprocket, reinstall the sprocket and cams
with the
bolts loose and rotate the crankshaft about 5 or 6 degrees without
allowing
the camshaft to turn. Then apply Loctite to the bolts one at a time
and
tighten them.

This camshaft degreeing will retard the power peak until a higher RPM
and
increase peak power at the expense of low end torque.





From: ? on 28 May 2010 10:03
On May 28, 5:48 am, "The Little Sister from Hell"
<totallydeadmail...(a)yahoo.co.uk> wrote:

> Devil's advocate and all that, but I've never heard of anyone
> successfully turbocharging a big single. Not saying it can't and
> hasn't been done, mind,
> but the exhaust gas pulsing would make it a nightmare job.
> Supercharging is a better way to go.

A Norton Manx didn't need no steenking stupidcharger, it took
advantage of
acoustic tuning in the induction and exhaust systems.

If Limeys could get 50 horsepower out of a 500cc engine sixty years
ago, a Yank can get 47 hp out of a 650 today using classical tuning
techniques.

From: TOG on 28 May 2010 10:18
On 28 May, 15:03, "?" <breoganmacbr...(a)yahoo.com> wrote:
> On May 28, 5:48 am, "The Little Sister from Hell"
>
> <totallydeadmail...(a)yahoo.co.uk> wrote:
> > Devil's advocate and all that, but I've never heard of anyone
> > successfully turbocharging a big single. Not saying it can't and
> > hasn't been done, mind,
> >  but the exhaust gas pulsing would make it a nightmare job.
> > Supercharging is a better way to go.
>
> A Norton Manx didn't need no steenking stupidcharger, it took
> advantage of
> acoustic tuning in the induction and exhaust systems.
>
> If Limeys could get 50 horsepower out of a 500cc engine sixty years
> ago, a Yank can get 47 hp out of a 650 today using classical tuning
> techniques.

Nobody's saying you can't. But you were saying you could do it just by
degreeing the cams (sic; plural) which was, is, and always will be,
bollocks.
From: The Older Gentleman on 28 May 2010 13:56
? <breoganmacbrath(a)yahoo.com> wrote:

> > Getting
> > back to where this started: "degreeing the cams" (whatever that is supposed
> > to mean) is not going to turn a 29 bhp stock bike into 50 bhp.
>
> I said 47 horsepower, not 50.

"As I pointed out to Sean *before* he bought his S40, you can get 50
horsepower out of that engine by degreeing the cams."

Or do you now claim that post wasn't made by you?


--
BMW K1100LT Ducati 750SS Honda CB400F Triumph Street Triple
Suzuki TS250ER GN250 Damn, back to six bikes!
Try Googling before asking a damn silly question.
chateau dot murray at idnet dot com
From: TMack on 28 May 2010 18:40
? wrote:
> On May 28, 10:07 am, "TMack"
> <tonyREMOVECAPSmac...(a)REMOVECAPS.dsl.pipex.com> wrote:
>
>> Lets be clear - we are talking about bhp at the at the back wheel.
>
> No, YOU are talking about rear wheel horsepower.
>
>
>> Getting
>> back to where this started: "degreeing the cams" (whatever that is
>> supposed to mean) is not going to turn a 29 bhp stock bike into 50
>> bhp.
>
> I said 47 horsepower, not 50.
>
> If you don't understand by now how camshaft degreeing affects power
> delivery, you haven't done any serious performance modifications.

If you are referring to the process of ensuring that the cam is exactly in
the right position, that will only optimise an engine in its existing
configuration. Given that nobody has EVER got more than 29 bhp out of a
stock S40 I fail to see how additional precision in cam alignment is going
to magically deliver another 21 bhp. Even a performance cam will only
provide a small improvement in that engine. People have tried a variety of
different grinds on the S40 cam but none have achieved more than a
relatively small improvement in horsepower - certainly not another 21 bhp.

Again - stop the bullshit. Give us ONE proven example of an S40 engine
delivering more than 45bhp at the back wheel.

--
Tony
'04 Ducati ST3, '08 DL650GT,
97 TW200, '87 semi-rat LS650, OMF#24


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