Lycoming engine fails! Pilot survives!

Peter Dohm wrote:

Corky Scott wrote:

On Wed, 03 Dec 2003 15:50:52 GMT, Peter Dohm
wrote:

As I recall, Blanton's conversion was originally for glider towing.
According to the story I was told, the reduction drive allowed the Ford
vee six to produce thrust similar to a much more powerful direct
drive aircraft engine--at towing speeds. Unfortunately, the story
later circulated that the engine produced mathematically ridiculous
amounts of horsepower...

So, I may eventually build with an automotive conversion. Or may not.
The choice is not "open and shut".

Regards,
Peter

Not exactly Peter. Blanton's conversion was for anyone who wanted to
use it, fast airplanes or slow. Turns out, one guy who did want to
use it belonged to an Aussie glider towing club. His original intent
was to see if he could certify the engine in Australia for that
purpose.

He got the engine and PSRU from Blanton at a time when Blanton was
declining in health and mind. The PSRU had a lot of problems and the
glider group spent a LOT of time refining the carburation and
induction. Eventually they got it right, both with the PSRU and the
induction and it's been towing gliders ever since. That was some
seven or eight years ago. The engine and PSRU are still going strong
and have not been overhauled or required overhaul since they finished
their development.

They tow gliders in their Pawnee with this engine, which in it's
former life, used a Continental O-470. The Ford 3.8 swings the same
prop the 0-470 did, at the same prop rpm. The Ford burns
SUBSTANTIALLY less fuel than the 0-470 did doing the same operation.

There's a very specific reason for this: The typical glider operation
involves a takeoff with glider in tow, a climb to 5,000 or so feet,
release and return to the airport for another tow immediately. That's
all it does, no cross country where the engine would be leaned out for
best fuel burn.

Under these identical operations, the Ford uses less fuel because once
the glider is cast off, the pilot simply closes the throttle to idle
and returns to the field with the engine at idle the entire time.
When they were using the 0-470, the engine came back under power and
also used full rich during the climb to release, which engaged the
power valve and used a lot of fuel.

As to the mathematically ridiculous amounts of horsepower being
reported, there was only one person claiming that, David Blanton, the
original developer. He was mistaken. Unfortunately, he had the type
of personality that did not allow him to accept criticism or
corrections (hmm, sounds like he'd fit right in here :-)). His method
of calculating horsepower had him claiming nearly 300 horsepower at
sea level for a 232 cid V-6 at 4800 rpm. Without supercharging,
that's just not possible. Others have checked their rated power with
a dyno and have produced a far more believable 180 to 235. The guy
who managed 235 got it by turning the engine at 5300 rpm. That's more
than I dare go. Almost all the builders use 4800 as the redline.

Blanton also originally specified a 500 cfm two barrel carburator. If
you do the math using the standard carb sizing formula from Holley
(Engine Size (CID) X Maximum RPM / 3456=CFM) you get 322.222 cubic
feet per minute (232x4800/3456). Sure, the 500 CFM carburator will
work, after all it did for years, but it's overkill and wastes gas.
Those who dared to buck Blanton (because they knew carburation, could
apply the formula and realised they were over-carbing) discovered that
using a 350 CFM carburator worked just fine, gave equal power but used
less fuel. This is not conjecture, this has been reported several
times by those who made the switch. One guy reported going from 9 or
10 (can't remember exactly) gallons per hour to 8 gallons per hour.

Blanton is gone now, and unfortunately his "take no prisoners" stand
in regards the horsepower issue, cost him a lot of credibility before
he died.

People still remember that issue when the mention of using a Ford V-6


You are exactly right, and I misworded my posting. However I never
realized that anyone, even Blanton, had been nutty enough to claim
rearly 300 horsepower. However, IIRC, Blanton claimed around 250 HP
from less than 4000 rpm. The power claim was preposterous, but at
least the speed and pressure wouldn't send parts flying.

BTW, I did see a Blanton powered Pacer at Willis GliderPort in south
east Florida a half dozen years ago. The previous owner had used it
to tow gliders, and it had been trouble-free. IIRC, it was operated
at about the same rpm, and produced about the same power, as Ford
would have specified in a car or truck--in other words 3600 rpm and
140 to 160 horsepower. However, the larger diameter prop was more
effective at towing speeds.

Peter

That was probably John Byrd's tug. Never had a wrench to it for about
800 hours now, doing nothing but glider towing. Let me amend that, he
has taken a couple of cross countries to SC and, I think, TX for glider
events.
--
Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL
Homebuilt Aircraft Newsletter"
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