V-8 powered Seabee

On Tue, 04 Nov 2003 16:52:42 -0600, Bob U. wrote:


"Morgans" wrote:

The 1500 FPM was probably on an optimum day, but it could also be because of
the PSRU, that the prop is bigger, and being turned with more torque,
allowing a bit more pitch.

Some folks wanna bee-lieve anything.
It would take a thermal to hoist this boat anchor at 1500 fpm.
Horsepower is horsepower is horsepower....
and so far, we don't have a clue what it is, do we?
Geejus H. Chryst, fella.

It is also not too hard to believe that it has better efficiency than the
Lycosarus.

Ah ****, doofus.
Do some homework...
or are teachers exempt.

Wake up and smell...
the *FRANKLIN*.


Read, SubUrban Bob
The plane in question has flown with both Lyco and Franklin power in
it's lifetime, from what has been stated here.

Now - as for efficiency. If the stock aircraft engine (any make) has
basically fixed timing (an impulse magneto to retard for starting) it
is optimized for only one combination of throttle position, mixture,
RPM, and load. That particular combination MAY never be realized.
The computer controlled system on even the lowliest of current
production automobiles optimizes the fuel mixture and ignition timing
for virtually all possible combinations of load, throttle opening,
RPM, as well as temperature and atmospheric conditions.
I know my 3.8 injected and electronically controlled 6 in my current
vehicle gives significantly better than a 30% improvement in mileage
over the 3.8 liter carbureted engine with mechanical timing advance on
my '75 Pacer did - and the van has a larger frontal area, weighs
several hundredweight more, and has air conditioning and an automatic
transmission. It is also capable of significantly higher cruising
speed, and accelerates MUCH more quickly - and the 232 inch AMC was
much more sophisticated in the control department than an old Franklin
or Lycosaur.
To go back just a bit farther, the 232 overhead valve engine in the
Pacer gave better mileage and performance than the low compression L
Head 231 in a '49 Dodge, of about the same weight.
Higher compression ratio, advanced combustion chamber design,
optimized fuel mixtures, and variable, closely controlled ignition
timing make a HUGE difference in engine efficiency and power output.

I know, Bob, you are going to say the optimized fuel mixtures and
closely controlled ignition timing are thrown out the window because
they are not running closed loop, having removed the O2 sensors.
Well, 14.7:1, or whatever the O2 sensor forces the engine to run at is
NOT the optimum for either power output or efficiency. It is simply
the mixture required for the catalytic converter to do it's job. By
removing the cat, and allowing the engine to run with a pre-plotted
mixture and timing map it can actually be MORE efficient, and more
powerful, than when constrained by the cat and O2 sensor.

The engine that was installed in the Republic SeaBee from the factory
was about equivalent, in technology and efficiency, with a 1932 Ford -
or even closer to a Model A.

The 60 hp Ford Flattie was about 209 cu inches displacement. It ran
6.6:1 compression ratio. That is basically a 3.5 liter engine.
In 1976, Ford's 200 cu inch six, with 8.7:1 compression put out 84
hp.
A 3 liter engine today can put out 200 HP - and at the same RPM as the
old Flattie still put out in excess of 160 ft lbs, at 3200 RPM,
roughly 100 HP.
The specific fuel consumption of the new engine is significantly lower
than the old engine,while producing almost double the horsepower.

In other words, SubUrban Bob, You are blowing smoke.

Barnyard BOb -- if it sound to good to be true, it is.