Scudrunners

Just wanted to toss this little formula out there:

Horsepower = (Torque X RPM) / 5252

Re-arranging:

Torque = (HP/RPM) x 5252


Therefore a Lyc 540 producing 300hp at 2700 RPM:

300/2700 * 5252 = 583 ft-lbs of torque, which is
a lot for a car engine.  Only the most recent, exotic
and expensive muscle cars will produce as much torque
as we've had for decades from Lycoming:

Acording to those graphs the car engine produces  more torque and 3 times more power than the Lycoming per cubic inch but probably  lose on the longevity department.

Not really, VanN...overhaul time on a regularly run 540 is what? 2500 hrs?  If those 'Vettes run at an average of 50 mph ( Im sure its much slower) then they will do 125k in 2500h.  Imm sure that theyd still be running well at that mileage.


Diiferent engins for differnt applicatins - a recent Toyota F1 engine was running ~750 hp at 19000rpm, giving 207lbft, while the Royal Hudson locomotive engines made 4700hp and 45,300lbft, but only 540rpm...

A corvette at 50 mph probably takes 5% of the peak
horsepower - if that.

A better comparison to a Lyc would be to take the
corvette or hellcat engine, and run it at peak hp
and RPM for 3 months continuously (2000 hours).

Obviously they would not last.  It took many
decades of development for NASCAR to build a
V-8 that would run wide open for FIVE hours.

You simply cannot compare automotive and
aircraft engines.  They are so wildly different.

Car engines are shitty in airplanes, and airplane
engines are shitty in cars.  Completely different
use cases, like comparing wrenches and screwdrivers.

You can use a screwdriver in place of a wrench,
and you can use a wrench in place of a screwdriver,
but why on earth would you?!

I have flown homebuilts with car engines, and
they are troublesome and dangerous and they
all crash.  Extremely high risk.  Makes surface
acro look like the safest thing around in comparison.

Off on a tengent -  a fewyears ago, whenI was on my employment drive, I got a flat near Golden, BC.  Dude who changed the tyre told me to come back the next day to recheck the lugnuts were at the correct 90 ftlb.  Not happening, says me - Ill be the other side of Calgary by then.  No worries, though - I weigh 160, my lug wrench is about 7 inches, so close enough to 90 ftlb, so I can do it myself.  Dude looks at me like I stepped out of a ufo, with a big wtf? look on his face.  Didnt have a clue what a ftlb was - just a number on a wrench that went click when it was reached.

So if I am following. Basically, engines in very expensive and exotic domestic production cars are catching up to the Lycoming engines in regards to power at around 2500 rpm.

Was this partially in response to a recent thread query on AvCan? "Why have cars improved so much in the last few decades but The mighty 172 is basically the same?" I of course paraphrased that.

vanNostrum wrote: Acording to those graphs the car engine produces  more torque and 3 times more power than the Lycoming per cubic inch but probably  lose on the longevity department.

Provided we ignore the engine speed.

At similar speed (RPM) they are all around 300 horse power on the graphs here.

mmm...bacon wrote: Off on a tengent -  a fewyears ago, whenI was on my employment drive, I got a flat near Golden, BC.  Dude who changed the tyre told me to come back the next day to recheck the lugnuts were at the correct 90 ftlb.  Not happening, says me - Ill be the other side of Calgary by then.  No worries, though - I weigh 160, my lug wrench is about 7 inches, so close enough to 90 ftlb, so I can do it myself.  Dude looks at me like I stepped out of a ufo, with a big wtf? look on his face.  Didnt have a clue what a ftlb was - just a number on a wrench that went click when it was reached.

First motorcycle engine I rebuilt at 12 years old, we used a fish scale on the end of a combination wrench to torque the head. Ran for years after that.


At least the tire changer didn't just switch directions on his air gun and he must have had some vague idea that bigger number = tighter.

I am sure the AME's on AvCan would shriek and
moan about this, but I don't use a torque wrench
on cars, boats, airplanes, motorcycles, whatever.

Don't need one.  Been wrenching for over 40 years
now.

You'll probably think I'm nuts, but I think it's the
single benefit I derived from a classical musical
education, a very long time ago. 

I have forgotten everything I learned about theory
of music, harmony, counterpoint etc as a kid, but
my fingertips remember.  Call me nuts.

I have forgotten everything I learned about theory
of music, harmony, counterpoint etc as a kid, but
my fingertips remember.  Call me nuts.
[/quote]

Colonel even though you have forgotten the musical education, your posts strike a cord or I should say a chord , some times majors other minors ,diminished or augmented it doesn't matter they always entertaining  and educational . I enjoy them

Thanks!  The nightmares about the sonatinas
and minuets have pretty well gone away now  ^-^

Every once in a while, I like to practice some
scales and arpeggios on some poor defenseless
instrument ... I have no idea why!

For those that don't know, music like engineering
is mostly applied physics.  What this means is
that when you get a bunch of physicists together,
it's not hard to put together a band.


[b]I'm Really Getting Fucking Old Moment[/b]

At a meeting yesterday, a friend of mine mentioned
a Prof at Stanford that we should hire.  Turns out I
remembered him as a skinny, short little teenaged
kid we hired as a summer student a few years (ok,
decades) back.  I remember dropping him off at
tennis lessons after work, because he was too young
to drive.

Fuck, I am getting old.  Be nice to see the kid and
get caught up, though.  Lost touch with him after
he went to White Sands.

I know a lot of people think I'm really fucking stupid
compared to them, but I've been lucky enough to
be around some incredibly bright people.  I mean,
really fucking smart people.  The combined IQ in a
10 foot radius of my desk chair would easily exceed
1000.