New R1/FZ1 4 valve engine tech questions? + other?'s

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Bob Nixon - 28 May 2007 19:58 GMT

I thought Yamaha going back to the simpler 4-valve scheme was a winner
for several reasons. There's no real advantage to high-end breathing
UNLESS you push the red line up to above say 15K RPM on 250cc-sized
cylinders. Ferrari found out long ago with their Quatrovalva engine
they were really no hotter than similar four valve engines.

That said, down to the meat of my question. Did Yamaha finally, like
the rest of the Japanese big four mfg's design in counter balance
shafts on the R1 engine like they did with their larger 1300cc engine.
I ridden at least 4 5 valve R1's or FZ1'a and they all buzz like crazy
at certain low usable RPM's, unlike the GSXR 1000 that is smooth as
glass until the revs go over 7-8K RPM. Also the GSXR 1000 always had
the low end nailed in terms of torque especially compared to the R1
engine that felt like a 600 down at 3K RPM (do mostly to the 5 valve
thing).
BTW, the new FZ1 is now fuel injected. NO?

Next question? How many of the NEW 600 to 675's have counter rotating
balance shafts designed in? I know for a fact that the 675 triple has
a single, compared to twin, on a four-cylinder engine, counter balance
shafts. Also, the 90-degree twins don't need balance shafts as they
have perfect primary balance but they still vibrate like hell on
acceleration or deceleration. I don't know if a balance shaft would
help this effect or not? BTW, the smoothest of the 4 stroke V-twins
that I've ridden is the SV-650, bar none (duc 749, 999 SV-1000, TL, 60
degree prillers, VTRs' TL's or RC-51's). I haven't ridden a parallel
four-stroke twin in at least 25 years but nowadays they use twin
counter balance shafts so they're probably similar feeling as a 90-
degree twin.

Two stoke parallel twins act more like a non-counter balanced inline
4's in terms of vibration due to twice as many power stokes per
revolution. Yes a bit buzzy but down low instead of up high in the rev
band. Has anyone ridden an inline or V four two stroke for engine feel
reference? BTW, this poster feels all singles, balance shafts or not,
is unsuitable for anything but the dirt or racetrack. IOW, only
limited (to the dirt & back) street usability.

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saddlebag - 29 May 2007 00:16 GMT

> I thought Yamaha going back to the simpler 4-valve scheme was a winner
> for several reasons. There's no real advantage to high-end breathing
> UNLESS you push the red line up to above say 15K RPM on 250cc-sized
> cylinders. Ferrari found out long ago with their Quatrovalva engine
> they were really no hotter than similar four valve engines.

Quattro means 4.

> That said, down to the meat of my question. Did Yamaha finally, like
> the rest of the Japanese big four mfg's design in counter balance
> shafts on the R1 engine like they did with their larger 1300cc engine.

You would think such things would be on the mfgs specs, but no.
Suzuki does note the gear driven counterbalancer on their "features"
page. Yami makes no mention of such a thing.

> I ridden at least 4 5 valve R1's or FZ1'a and they all buzz like crazy
> at certain low usable RPM's, unlike the GSXR 1000 that is smooth as
> glass until the revs go over 7-8K RPM.

Prolly why Yami makes no mention of such a thing.

> Also the GSXR 1000 always had
> the low end nailed in terms of torque especially compared to the R1
> engine that felt like a 600 down at 3K RPM (do mostly to the 5 valve
> thing).
> BTW, the new FZ1 is now fuel injected. NO?

Yes, but it still uses the old Genesys engine.

> Next question? How many of the NEW 600 to 675's have counter rotating
> balance shafts designed in?

Not exactly a touring platform, so I doubt anyone would add the
weight.

> Also, the 90-degree twins don't need balance shafts as they
> have perfect primary balance

So do IL4s, it's just that their secondary vibes are at four times the
frequency of the twin's secondary vibes making the sensation more
pleasing to bees than humans.

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Bob Nixon - 29 May 2007 03:25 GMT

> > I thought Yamaha going back to the simpler 4-valve scheme was a winner
> > for several reasons. There's no real advantage to high-end breathing
[quoted text clipped - 3 lines]
>
> Quattro means 4.

^^^^^^^^^^^^^^^^^^^^^^

What did they call their 5 valve ingine then. Synco doesn'r sound
right???

> > That said, down to the meat of my question. Did Yamaha finally, like
> > the rest of the Japanese big four mfg's design in counter balance
[quoted text clipped - 3 lines]
> Suzuki does note the gear driven counterbalancer on their "features"
> page. Yami makes no mention of such a thing.

Then it must not have changed.

> > I ridden at least 4 5 valve R1's or FZ1'a and they all buzz like crazy
> > at certain low usable RPM's, unlike the GSXR 1000 that is smooth as
[quoted text clipped - 15 lines]
> Not exactly a touring platform, so I doubt anyone would add the
> weight.

It just makes them more ridable at the track too as does the extra mid
range of a 675 which BTW weights in at <= to the Japanese 600's. Maybe
the added cost of twin balancers on an I4 would make them
<comprtitively priced? Anyway, most 600SS's are bought by 18-25 year
olds as a 1st bike instead of their intended purpose as a track
weapon. Squid factor + < insurance costs, I suppose.

> > Also, the 90-degree twins don't need balance shafts as they
> > have perfect primary balance
>
> So do IL4s, it's just that their secondary vibes are at four times the
> frequency of the twin's secondary vibes making the sensation more
> pleasing to bees than humans.

-------------------^^^^^^
Amen!

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Robert Striemer - 29 May 2007 02:01 GMT

>I thought Yamaha going back to the simpler 4-valve scheme was a winner
> for several reasons. There's no real advantage to high-end breathing
[quoted text clipped - 25 lines]
> counter balance shafts so they're probably similar feeling as a 90-
> degree twin.

re. || twins
see
http://www.motoring.co.za/index.php?fSectionId=1828&fPicId=78815

or

http://www.advrider.com/forums/showthread.php?t=218631
for BMW's solution (F800S/ST) third picture

or
http://www.motoring.co.za/index.php?fArticleId=3191063

"
The most striking characteristic of the F800S sports machine, and its
touring sibling the F800ST, is its upright, parallel twin-cylinder engine.
This is the way British manufacturers including Norton and BSA made bikes in
the 1950s. The long piston stroke it permits and the momentum of two pistons
moving in tandem maximises torque. The configuration is also slim. But older
riders remember parallel twins for tooth-loosening vibration that got worse
as engine revs mounted. In those days the only compensation was a gorgeous
noise.

The F800 has the sound and I love it. But the vibration has gone. An
ingenious, additional swivelling con-rod allows this twin to rev beyond
8,000rpm while remaining velvety-smooth all the way. The all-new 798cc
engine was developed in partnership with the Austrian specialist
Bombardier-Rotax and is built for BMW at the Austrian Rotax factory. It is
an impressive innovation which reveals more character the harder you thrash
it.
"
http://www.motoring.co.za/index.php?fArticleId=3218340&fSectionId=882&fSetId=381> Two stoke parallel twins act more like a non-counter balanced inline> 4's in terms of vibration due to twice as many power stokes per> revolution. Yes a bit buzzy but down low instead of up high in the rev> band. Has anyone ridden an inline or V four two stroke for engine feel> reference? BTW, this poster feels all singles, balance shafts or not,> is unsuitable for anything but the dirt or racetrack. IOW, only> limited (to the dirt & back) street usability.>

Reply to this Message

Bob Nixon - 29 May 2007 03:28 GMT

> "Bob Nixon" <bigrex2...@yahoo.com> wrote in message
>
[quoted text clipped - 21 lines]
>
> - Show quoted text -

I like the inovation of that new counter-balancer + the belt drive.

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Motorcycle Forum / General / Sportbikes / May 2007

New R1/FZ1 4 valve engine tech questions? + other?'s