Hyabusa flat 8

On 6 Mar, 11:03, bod43 wrote:
On 5 Mar, 21:57, "Morgans" wrote:

snip interesting stuff

Maybe someone on uk.rec.motorcycles might have an
idea as to the expected life span of a hyabusa engine
when operated in a constant load regime,
say at 130bhp.

You'd need to boost the low and midrange torque to swing a prop, as
props rotate relatively slowly, don't they? I think a 'Busa engine
would last forever is detuned to 130bhp.

A Gold Wing 1500 or 1800 lump might be more suitable, IMHO.

Using the patented Mavis Beacon "Hunt&Peck" Technique, "TOG@Toil"
typed
On 6 Mar, 11:03, bod43 wrote:
On 5 Mar, 21:57, "Morgans" wrote:

snip interesting stuff

Maybe someone on uk.rec.motorcycles might have an
idea as to the expected life span of a hyabusa engine
when operated in a constant load regime,
say at 130bhp.

You'd need to boost the low and midrange torque to swing a prop, as
props rotate relatively slowly, don't they? I think a 'Busa engine
would last forever is detuned to 130bhp.

Depends on the prop, but I would think that gearing down would be the
way to go.

--
Wicked Uncle Nigel - "He's hopeless, but he's honest"

It's important is that last ell.

Wicked Uncle Nigel wrote:
Using the patented Mavis Beacon "Hunt&Peck" Technique, "TOG@Toil"
typed
On 6 Mar, 11:03, bod43 wrote:
On 5 Mar, 21:57, "Morgans" wrote:

snip interesting stuff

Maybe someone on uk.rec.motorcycles might have an
idea as to the expected life span of a hyabusa engine
when operated in a constant load regime,
say at 130bhp.

You'd need to boost the low and midrange torque to swing a prop, as
props rotate relatively slowly, don't they? I think a 'Busa engine
would last forever is detuned to 130bhp.

Depends on the prop, but I would think that gearing down would be the
way to go.

The thing that everyone seems to forget when promoting automotive engines
for aircraft is that most piston aero engines have a very hard life.
Take-off and climb is full power or very nearly, then they throttle back to
cruise at 75% or thereabouts. The only roadgoing vehicles that approach
that sort of use are in motorsports, and how long do they last?

Wicked Uncle Nigel wrote:

You'd need to boost the low and midrange torque to swing a prop, as
props rotate relatively slowly, don't they? I think a 'Busa engine
would last forever is detuned to 130bhp.

Depends on the prop, but I would think that gearing down would be the
way to go.

If you're forced to use a higher-revving engine, yes- but gearboxes
or belts and cogs introduce problems of their own, which is why a
relatively large displacement slow-revving engine (which doesn't need
four valves/cylinder, multiple chain drive cams with cam chain
tensioners, etc.) makes a lot of sense for aircraft.

"bod43" wrote in message
...
I have the idea that mechanical failure of the original 4 cyl
engines (or any high performance japanese bike engine) is
pretty much unheard of but I am not at all sure.

It matters little, because now you are making a whole new engine for a
totally different application, with no track record and the distinct
possibility of new and exciting failure modes. Further, the same can be
said about the reiliability for most any automotive engine in its intended
application, but the track record of automotive aero conversions is spotty
at best.

Just thinking outside the box... Since the proposed Hyabusa Flat 8 engine
will need a PSRU anyhow; how about two Hyabusa engines put together into a
twin-pack? The result would likely weigh a tad more than a simple flat 8,
but now you have two known engines combined with twin-engine redundancy.

Vaughn

On Mar 6, 8:38*am, "vaughn" wrote:
"bod43" wrote in message

...

I have the idea that mechanical failure of the original 4 cyl
engines (or any high performance japanese bike engine) is
pretty much unheard of but I am not at all sure.

* *It matters little, because now you are making a whole new engine for a
totally different application, with no track record and the distinct
possibility of new and exciting failure modes. *Further, the same can be
said about the reiliability for most any automotive engine in its intended
application, but the track record of automotive aero conversions is spotty
at best.

Just thinking outside the box... *Since the proposed Hyabusa Flat 8 engine
will need a PSRU anyhow; how about two Hyabusa engines put together into a
twin-pack? *The result would likely weigh a tad more than a simple flat 8,
but now you have two known engines combined with twin-engine redundancy.

Vaughn

There is little difference between the existing V8 Hyabusa and a flat
8 in terms of bottom end design. The V8 has proved bulletproof
@400HP. Pretty much everything learned with the V8 Hyabusa conversion
applies to a flat 8.

Of course it would need to be geared - torque peak is near 8000 RPM.
However, there is a weight trade off. These little screamers, which
are more like turbines than tractors, can use a light crank because
they use a whole lot of tiny power pulses instead of a few humongous
ones to produce power. The Hyabusa is on the extreme opposite end of
the power/RPM spectrum from a Lycoming.

Weight savings in the crank can be shifted to the PSRU which would be
a planetary gearset with maybe 5 planet gears for lots of tooth
engagement and strength. The gear ratio would need to be 4 or 5:1 so
spur gears or cog belts aren't the best choice since the small gear or
cog would be small with too few teeth engaged. A planetary allows
large ratios with lots of tooth engagement for strength.

Keep in mind how the motorcycle works. The bike has a 6-speed gearbox
whereas the airplane engine would have only one. The standard sport
bike shift technique, approved by the factory, is to apply a large
force to the shift lever and then tap the clutch lever when the rider
wants to shift. This results in an instant shift with horrific
transient loads suffered by the crank and drive train. An aircraft
powerplant would never see this abuse.

Why is a flat 8 better than a V8? Mainly a higher thrust line for
prop clearance and better ballance. To do that with a V8, it would
have to be inverted.

bildan wrote:
snip

Keep in mind how the motorcycle works. The bike has a 6-speed gearbox
whereas the airplane engine would have only one. The standard sport
bike shift technique, approved by the factory, is to apply a large
force to the shift lever and then tap the clutch lever when the rider
wants to shift.

I don't think it is, you know. ISTBC of course.


--
Catman MIB#14 SKoGA#6 TEAR#4 BOTAFOF#38 Apostle#21 COSOC#3
Tyger, Tyger Burning Bright (Remove rust to reply)
116 Giulietta 3.0l Sprint 1.7 145 2.0 Cloverleaf 156 V6 2.5 S2
Triumph Sprint ST 1050: It's blue, see.
www.cuore-sportivo.co.uk

"vaughn" wrote in message
...

"bod43" wrote in message
...
I have the idea that mechanical failure of the original 4 cyl
engines (or any high performance japanese bike engine) is
pretty much unheard of but I am not at all sure.

It matters little, because now you are making a whole new engine for a
totally different application, with no track record and the distinct
possibility of new and exciting failure modes. Further, the same can be
said about the reiliability for most any automotive engine in its intended
application, but the track record of automotive aero conversions is spotty
at best.

Just thinking outside the box... Since the proposed Hyabusa Flat 8 engine
will need a PSRU anyhow; how about two Hyabusa engines put together into a
twin-pack? The result would likely weigh a tad more than a simple flat 8,
but now you have two known engines combined with twin-engine redundancy.


Eliminate a lot of question marks with the experimental crank and rods too.

In article ,
says...

"bildan" wrote in message
...
'been scratchin' some paper.

It looks like a 2.6L flat opposed 8-cylinder could be made will not
too much difficulty from two Suzuki Hyabusa motorcycle cylinder
blocks. The electronic fuel injected 'busa puts out about 130HP so
two theoretically could make 260HP.

With 8 cylinders, the power pulses overlap a little so wouldn't put
too much stress on a planetary PSRU in a nose case.

In the opposed configuration, the stock rods work so only the crank,
PSRU and case would have to be fabricated. CNC does that sort of
thing well.

The result would be smaller and lighter than an O-200 - although that
doesn't take the liquid cooling system into consideration. Still
scratchin' but this thing looks cool.

Cool, indeed! How much do you think you would have to sell it for, if you
were to sell them?



http://www.h1v8.com/page/page/1562068.htm

Hartley is pushing his nice V8 busa in every race series but it's kinda
expensif.

HTH

Tom -lurking and enjoying the knowledgable posts- De Moor