AI Nut
Still working on using that Ford 1.9L engine in a Mustang II.
An auto piston engine like that is a super light duty engine
(maybe 30 HP continuous). You are asking it to put out at least
150 HP all of the time. I thought it was a 4.1 liter V6.
You got a screaming hand grenade there :-)>
Good luck.
Paul Lamar
Yikes. Paul is absolutely right, but perhaps too generous. 1.9L is
115.9 cubic inches. Even if it were as robust as an aircraft engine,
it would likely produce 55 hp. As to life, keep it under 25 hp and
you could expect it to live. Try to get 100 hp and you'll get a
very short life, esp on exh valves and pistons. If your PSRU
doesn't have a pair of external bearings on the crankshaft gear or
pulley, the crank will break due to side load from the belt/chain/
gears.
Good luck, what is the stall speed of the M II?
Bill Freeman
Long EZ builder & pilot
BSME, MSME
EAA Technical Counselor
Stall speed on this particular animal is about 70 mph according to the
previous owner. ASI indicates mph and not knots, knotty, huh?
The engine type, 1.9L HO EFI has 143 hp according to Ford. However,
several of them have been dynoed indicating about 110 hp at the
flywheel. Thanks, Ford. Several people have added turbos to this
engine and performed long circle and oval track races and the engine
holds up just fine at high continuous hp output. If it weren't for that
empirical evidence, I wouldn't trust it either. A few have pushed turbo
assisted hp up to 330 but they only talk about 1/4 mile runs; engine
still works fine, lasts long time (with forged pistons and rods.)
Limits on the airframe are 180 hp continuous with 210 hp peak max. I
expect that during cruise, it will only be generating about 80-120 hp
like the Lyc's. That should give me 160-170 mph cruise like the
previous owner had with an O-320. Wheel pants and a few other
inexpensive mods should raise that by about 50-60 mph with no increase
in hp output, according to Kent Paser's book and empirical evidence from
other MII owners who have done it.
The PSRU is a Dave Blanton model, with external bearings (large ones)
IIRC.
Thanks for the help!
AI Nut
Those kinds of races are typically less than two hours and the engine
is junk at the end of the race if they are competitive. Mazda rotary
engines will run for years in the same kind of races.
Most people cruise their 150 HP O-320
Lyc at 70% power or 105 HP, that is about 22 inches of manifold pressure
or there about. You will have to run about 10 psi boost all of the time
to get the same power with one third the displacement. That is
about 20 inches of Hg above atmospheric. That means you will have to
run that tiny engine at roughly 5500 RPM and 45 inches Hg manifold
pressure all the time during cruise to get the same performance. The
stress on all the parts is corresponding much higher so the life due
to fatigue of the reciprocating parts will be short. I predict the
exhaust valves will be the first to give up. The most likely time
for it to fail is during full power takeoff which will put you in
dire straits.
My calcs show that the 65% cruise hp is at 3300 rpm, with 120 hp.
Actual redline of the engine is 6000 rpm, and with a 2:1 PRSU I wish to
derate it to 5400 rpm. With 12 lbs of boost, that yields 185 hp,
artificially keeping the Warp Drive prop limited to 2700. However,
several parameters are variable here.
1) Warp Drive prop pitch (ground adjustable)
2) engine rpm limit along with prop rpm -- Warp Drive says that as long
as you stay subsonic (I've read .85 mach) that the props can keep up
just fine, there is no sweet spot for their design, nor is their an
upper rpm limit (within reason of course.) If I turn the engine all the
way to 6k rpm, 205 hp is produced.
3) boost is variable from 12 to 30 on the turbo I have. However, I
intend to limit it to 12 max for fear of running into the detonation
area. Ground engine tests will tell the tale there. I wish I knew an
easy, nondestructive method of varying the boost from 5-12 so that I can
start my tests in a much more conservative regime. The factory said
that I could drill a hole in the wastegate to lower boost levels, but
that is permanent and is too drastic a solution for me.
Takeoff tests can be performed locally on a 6000 foot runway during the
day, or if I want to wait until after midnight and before 6 am, I can
use a 10,000 foot runway at the part-time class C (it's also a lot
closer.) Lift off in this bird is about 550 feet, giving me a mile or
two to get back down should the engine go south.
Why the 1.9L Ford four cylinder engine? What is your reasoning? What
does it weigh with the turbo?
My reasons to purchase that engine were:
1. Dave Blanton, who AFAIK was well respected for his aeronautical
engineering prowess, strongly recommended that engine, and even
mentioned that it would work well in a Mustang II.
2. PSRU came with it, saving me lots of money.
3. Blanton said Ford claimed the engine produces 143 hp -- Motor Manuals
confirmed that value but they must have also been taking Ford's word for
it.
4. Blanton was very enthusiastic about this engine for several reasons.
Too bad they were only in production for a short while. He put one
(normally aspirated) in a Cessna 152 for testing. With the Continental
engine their prop would only turn about 2500 rpm; with the 1.9L HO it
would turn past 2700 but he limited it to 2700 (prop limit?)
5. It is computer controlled so mixture is optimized for temp and
alititude.
6. It has electronic fuel injection.
7. Parts are available almost everywhere.
8. I can run mogas, if I use octane enhancer. In fact, the 100LL will
cause the O2 sensor to fail in less than a tankful (25 gallons.) I'd
have to take the sensor out and burn it for 10 minutes with a propane
torch to get the lead off.
9. Water cooled engines are more fuel efficient than air cooled ones.
10. Auto engines are much more reliable than "certificated" engines.
11. Overhaul costs are less than 1/10th (sometimes less than 1/100th)
the cost of "certificated" overhauls.
12. Even though the stock engine doesn't actually produce what Ford says
it will, I have too much money in the system to change until the engine
proves itself unworkable. Turbocharging and intercooling it should cost
me less than $700 versus $7k for another auto engine (rotary), mount,
and psru, or $7k for a high time unreliable certificated engine and
different prop.
With turbo, water and all accessories, about 370 lbs, and another 12 lbs
for the ground adjustable prop. Comparing weights, the previous engine
was the O-320 (298 lbs? without accessories) with a Hartzell constant
speed prop (52 lbs?. The Ford weighs a couple of pounds more, but the
moment arms are better, since the prop is 40 lbs lighter.
Keep us informed of your progress as it is always nice to have someone
confirm conventional wisdom from time to time.
Confirm conventional wisdom? Many possible interpretations of your
line. As in confirming that the engine won't work as planned?
Good Luck
Thanks!!!
Paul Lamar
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 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
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