Please, if I am wrong with any of this, let me know (except for the
religious debate regarding auto versus certificated.)  Yes, several
people have theorized that the little engine will be overworked and will
self destruct shortly.

It has nothing to do with religion.
Don't fool yourself. Run the calculations on average car HP required

yourself.

The frontal area (FA) of a car is around 18 square feet. Don't take my

word

for it measure it.  The drag factor Cd is .35. Probably .32 for a modern

car.

Drag is Cd times FA times MPH squared times air density factor(.0026 at

sea level).

Aero HP necessary is drag times velocity in feet per second divided by

550.

Rolling HP required is about equal to drag HP at 60 MPH and is a linear
function of speed.

You can calculate the additional HP to climb a hill by knowing
how fast the load is going straight up. On a 3% grade you go
straight up 3% of the distance you move forward. 550 pounds moving
straight up at one foot per second is one HP.

If you cannot do the calculations install a manifold pressure
gage and monitor that. If this does not convince you you have
no business using this engine in an airplane that requires
150 HP. It might work fine in an ultrlight at 80 HP or so if
you could get it off the ground due to the extra weight.

I can only counter that that hasn't happened
when people have actually used the engine in the higher hp ranges, some
for over 100k miles with mixed regular and race driving.  I don't count
the 330 hp versions that are used for street driving and drag strips, as
3 out of 8 of those that I've talked to have blown up.  None of the 200
hp versions have done so except one that had a faulty wastegate that
spiked to over 30.

AI Nut

Racing and road driving does not count. Not the same duty cycle
as aircraft.

How many turbo 1.9L Ford engines have you seen flying around in airplanes?
If you crash or kill yourself people will say; "just another auto engine!"

Paul Lamar

Al,

Nothing personal intended by any of my comments just the facts as I see
them. An O200 produces about 100 hp from 200 cubic inches of displacement.
That is .5 hp/cu. in, 1.9 L is Apr 116 cu in. At your cruise number (120 hp)
you are asking this engine to produce slightly over 1 hp/cu. in AT 65%
CRUISE!!!! Now I know that this engine is liquid cooled, and the 0200 is air
cooled, but this makes very little difference in the egt. You will probably
be running at a leaner mixture and will therefore have a higher egt. You do
not have the luxury of inconel, sodium-filled valves with a .5" diameter
exhaust valve stem for heat rejection. The exhaust valves will get hammered
big time. Also you may find that you have piston cooling problems as well.
You will need oil spray cooled pistons. The cooled piston is a trick used by
all the turbo cars (F1 etc) and they junk the engine after every race. They
make silly HP#'s for a short period of time, not reasonable hp for extended
periods.

I too looked at using a small V6 and looked very hard at the GM 2.8 L
engine. It has enough displacement and makes enough power. It could actually
work using direct drive. With a redrive it is even better. It is a 60 deg V
and does not have the shakes like a 90 deg V6. The largest displacement
possible without Siamese bores is 3.2L (195 ci) I believe. Siamese bores are
no good for heat rejection and symetric cylinders in a highly loaded engine.

The only other piston engine I looked at seriously is the small block ford
V8. Both of these engines could probably be made to work if they had
oil-cooled, forged pistons, titanium valves etc. (BTHW titanium is great for
heat tolerance, but it is also very notch sensitive and prone to fatigue
failure) Not exactly a good scenario for trouble free life and a long TBO.

You are trying to do this with a very small displacement engine(almost half
the size of the 3.2L), which means you will really have to wind it up tight.
That makes for great power numbers in road and track, but not good for an
airplane engine. The reason I settled on the rotary is the lack of exhaust
valves and the basically bullet proof design. Don't get me wrong, I love the
sound of a finely tuned piston engine, and nothing gets me excited as much
as a low flying Merlin at full bore, but facts is facts. Those aircraft
piston engines were specifically designed for the task at hand and differ
greatly from your auto, which is designed to use the cheapest possible
materials, and barely survive with grandma at the wheel. Just let boy racer
get ahold of one for a couple years, and you will see smoke at least, if not
parts out the tail pipe. The piston aircraft engines of yore also required a
LOT of maintenance to keep them flying and did not have long TBO's. They
were designed to go to war and be maintained by Uncle Sam's deep pockets.
(If they didn't get shot down first). There have been many people, including
government funded corporations that tried to adapt the auto piston engine to
an aircraft (Orenda) and had a lot of trouble.

Just be careful if you continue with the ford 6. Use an airport with lots of
places to land (like a dry lake bed) I know that this can be a harsh crowd
if you are not a rotor head, but I assure you our criticism is only intended
to be constructive. I hope you make us all look like fools, because I hate
to be the bad guy, but I also worry about the safety of your engine choice.

Monty

 
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