Hyabusa flat 8

"Maxwell" #$$9#@%%%.^^^ wrote in message
...

"platypus" wrote in message
...
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?


Not true at all.

Ever driven a gas powered motor home, pulling a boat trailer. I drove a
6500 series Chevy dump truck years ago, always pulling a Case 580C back
hoe. It was 100% power almost all the time, and always at lease 75% on the
highway. I have seen lots of auto engines successfully suffer MORE abuse
than aircraft engines in many circumstances, and most often do it without
proper maintenance. Some school bus and UHaul truck engines deserve to be
in the Motor Sports Hall of Fame.

But that doesn't solve all the propeller and PSRU issues.



Nicely said.

On Fri, 6 Mar 2009 13:11:32 -0600, "Maxwell" #$$9#@%%%.^^^ wrote:


"platypus" wrote in message
m...

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?


Not true at all.

I drove a 6500
series Chevy dump truck years ago, always pulling a Case 580C back hoe. It
was 100% power almost all the time, and always at lease 75% on the highway.

But that;s true of nearly all agricultural vehicles, which is why they
tend to use understressed, low-revving, low-tech motors. And just
because you can drive them on the road doesn't make the road-going
vehicles.

"TOG@Toil" wrote

Which was what I was thinking. I mean, what was max revs for a Merlin?

Googles

Hm. About 3000rpm. Just off tickover for a 'Busa.

But all the high power Merlins and such had gear reducing for their props.
They had to, to keep tip speed down for their gigantic props.

Gear reducing is doable. Even more used, and very, very reliable, are belt
PSRU units. Replace the belt at 200 hours or so, and fly with confidence,
if the bearings and such are properly designed.
--
Jim in NC

"Ace" wrote in message
...
On Fri, 6 Mar 2009 13:11:32 -0600, "Maxwell" #$$9#@%%%.^^^ wrote:


"platypus" wrote in message
om...

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?


Not true at all.

I drove a 6500
series Chevy dump truck years ago, always pulling a Case 580C back hoe. It
was 100% power almost all the time, and always at lease 75% on the
highway.

But that;s true of nearly all agricultural vehicles, which is why they
tend to use understressed, low-revving, low-tech motors. And just
because you can drive them on the road doesn't make the road-going
vehicles.


These were not ag vehicles. Passenger car engines were popular back then in
all the class C motor homes, school buses, and light weight dump trucks. My
Chevy was a 350-2v with probably nothing more than the heavy duty 4 bolt
main block. It also had a 4 speed manual transmission, and 2 speed rear. I
would commonly shift the low gears as high a 4000-5000 rpm. The gross weight
on the entire package was around 30,000 lbs.

Champ wrote:
... automotive engines
for aircraft ... 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?
....
It's perfectly possible to tune and engine to the load you describe
*and* achieve high reliability.

SW Oklahoma is arid, so there is plenty of business for engine
rebuilders, dealing with the farmers who run (ex-) auto engines
at high load - day and night - for the irrigation season. The hours rack
up fast.

I talked to one builder 2 or 3 years ago. Details escape me now, but the
approach was not that dramatic, to produce a 10 thousand hour engine BMO
That's when an engine doing 2000 hours in a season, lasts several years.
They use auto cutouts for low oil, and hot cooling water of course.
Oh yes, they tend to run them on natural gas. That's quite a favorable
factor, apparently.

The load is relatively kind, it's true - a water pump: kinda like the
fluid flywheel on an automatic. The bores are hard chrome, the valves
are metal cooled, the seats are hard-faced inserts(If I remember...)
some other details of that kind.
The oil changes are a religious ceremony.

Brian W

TOG@Toil wrote:
... I mean, what was max revs for a Merlin?

Googles

Hm. About 3000rpm. Just off tickover for a 'Busa.

I THINK that was the prop shaft - like many other aero recips
it's limited by 0.9 c at the prop tips at the top end of the tach.
But the crank was driven by pistons breathing gas though a duplex
compressor system - driving a PRU.
Then again - in War mode its overhaul time was measured
in the hours you can count on one to two hands.
Low compression heads on the Merlin
were the choice for civil airliners post war.

Brian W

On Mar 6, 1:10*pm, Catman wrote:
bildan wrote:
On Mar 6, 10:26 am, Catman wrote:
Grimly Curmudgeon wrote:
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Catman
saying something like:
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.
Some people just like rebuilding gearboxes.
I must confess I'm not massively keen on it. I tend to stick with the
'pull clutch, change gear, release clutch' technique. Unless I'm doing
clutchless upshift, 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

Of course! You're thinking of ENGLISH bikes - that's different. *We
all know how reliable those are. *If the tranny can be shifted without
a clutch, it's not a Japanese sport bike.

Oh dear.



My Kawasaki can't be shifted without the clutch but it shifts great
with the pre-load & clutch method and has done so reliably since '86.

Can't afford a newer one?

--
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

Don't need a new one - It's a Japanese motorcycle and they run
forever. However, my old Triumph Bonneville wasn't safe to ride
further than I was prepared to push it - something about the Lucas
electrics. You know, Joe Lucas, Prince of Darkness.

On Mar 6, 6:30*pm, Brian Whatcott wrote:
TOG@Toil wrote:
... *I mean, what was max revs for a Merlin?

Googles

Hm. About 3000rpm. Just off tickover for a 'Busa.

I THINK that was the prop shaft - like many other aero recips
it's limited by 0.9 c at the prop tips at the top end of the tach.
But the crank was driven by pistons breathing gas though a duplex
compressor system - driving a PRU.
Then again - in War mode its overhaul time was measured
in the hours you can count on one to two hands.
* Low compression heads on the Merlin
were the choice for civil airliners post war.

Brian W

..9C!!!! I've heard of a Warp Drive propeller but 90% the speed of
light! Wow.

On Fri, 6 Mar 2009 18:32:24 -0600, "Maxwell" #$$9#@%%%.^^^ wrote:


"Ace" wrote in message
.. .
On Fri, 6 Mar 2009 13:11:32 -0600, "Maxwell" #$$9#@%%%.^^^ wrote:

I drove a 6500
series Chevy dump truck years ago, always pulling a Case 580C back hoe.

But that's true of nearly all agricultural vehicles,

These were not ag vehicles.

*Whhhooooooosh*

Ace wrote:
On Fri, 6 Mar 2009 18:32:24 -0600, "Maxwell" #$$9#@%%%.^^^ wrote:

"Ace" wrote in message
...
On Fri, 6 Mar 2009 13:11:32 -0600, "Maxwell" #$$9#@%%%.^^^ wrote:

I drove a 6500
series Chevy dump truck years ago, always pulling a Case 580C back hoe.

But that's true of nearly all agricultural vehicles,

These were not ag vehicles.

*Whhhooooooosh*

This isn't going well, is it?

--
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