"Perry J. Mick" wrote:
Bill Freeman wrote:
OK, given that I am an unbeliever, I think there are several
possibilities to help reliability. Here are some:
1) Don't fly with a junkyard engine. Overhaul it first to
check out the internal condition and upgrade as per the
"lessons learned". No offense, Perry, please - we're learning
here. I was unwilling to fly with a "used" certified engine. I
use one overhauled by an A&P that I knew personally, and
it was originally intended for his son. (high "give-a-sh*t factor").
I'm back home now. Took longer to get home by flying tube
than it did to fly out by Long-EZ, if you include the waiting at
the airports and the drive time.
I originally intended to fly it only the first 40 hours and then rebuild.
But it was running so well I just kept going. Flew most of my 165
hours within 5-10 miles of MMV waiting for things to fail. Of
course they then fail on x-country while "venturing out". This is
my first major failure.
So now it is being rebuilt, and customized in the process for
my application.
2) Add a static pressurization system like Paul has shown and
rig up a ground accessible fitting, like in the oil filler door area
or air outlet area, or somewhere else accessible. Using a
REGULATED !!!!! air supply, bring the system pressure up
to rated + some safety factor with the engine cold and leave
while you load fuel, baggage and preflight. Look for coolant
leaks with max cowling access for inspection, and loss of
initial pressure over the preflight period. Pressure loss or
coolant leaks are an obvious 'no-go'.
I'm planning to install the tire valve in the top of the rear housing,
so a pressure check can be done every time the cowl is off. It
can also be used to bleed air when the system is being filled.
3) Consider an emergency cooling system, perhaps drilling the
water jacket on the hot side for fittings from a pressurized
tank with an emergency-on valve. Lose coolant, punch up
"nearest airport" on GPS, change heading, reduce power to
minimum flyable, go full rich (perhaps "emergency super rich for
cooling" setting on Tracy's FI system??) and turn on the "one shot
emergency cooling system" to dump 2-3 gallons of water into
the cooling passage at the hottest points thru internal spray nozzles
to give a slow dump time, perhaps 5 minutes or so. If you pressurize
the tank to 75 psi, it will spray the water into the passages and get
you perhaps 3-5 minutes of extra engine life, maybe more with
low enough power setting. Could make the difference between
landing on a runway or in a field or trees.
Actually it never overheated in the air, the overheating came after
landing during taxi, four times, got progressively worse each time.
I could tell I needed to land because when the overflow bottle
overflows, I can see it because I installed a vent that exits above
the right top cowl. That along with slowly increasing water temps
gives me some warning that things are awry. I use the later
second gen rx-7 overflow bottle cap that has a vent line.
4) The **best** solution is still to use EXTREMELY high quality
plumbing on your system. I do believe that hose clamped
systems CAN be made reliable (witness all the Hondas and
Toyotas out there) IF, IF, IF they are VERY carefully
engineered with highest quality hoses replaced regularly and
*proper* fittings and clamps. Spring type clamps are the standard
on Hondas, and I believe are more reliable than screw type, which
can lose tension as the rubber crushes beneath them with heat and
time. My screw clamps on the air induction tubes (rubber hose
connectors) of my Lyc are essentially always in need of a bit of
tightening.
I agree, the new engine will have the heater port of the engine tapped
with 1/2 NPT to eliminate the hose barb.
--
Perry Mick
Duckt N7XR
http://www.ductedfan.com
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