----- Original Message -----
Sent: Sunday, February 08, 2009 10:07
PM
Subject: [FlyRotary] New failure
mode
Sent: Sunday, February 08, 2009 5:30
PM
Subject: [FlyRotary] NEW failure mode for
13B
Well, I haven't heard of this happening before --
I was ground running my engine to tune it with the EM-2 and EC-2.
Ran for almost an hour, at various rpm's to change the manifold pressure and
tweak the settings. Cooling working well, I had the top cowling off to allow
good exit area since I was tied down. Coolant pressure about 14 psi as
reported on the EM-2.
Engine was running good, took it up to ~6000 rpm
swinging a 76x76 Catto prop, when suddenly there was steam and fluid on my
windshield. Shut it down by killing power to the EC-2. Coolant
everywhere.
Got out and looked to diagnose the problem -- NOT
my plumbing. A FREEZE PLUG in the iron housing had blown out. Rapid
coolant dump.
Secondary effect -- Since I shut down suddenly
from full tilt, either the proximity of the cowl to the exhaust, or possibly
some of the coolant on the exhaust started a small fire on my cowl. Put it out
with extinguisher, but corner is charred.
Bill Schertz
KIS Cruiser
#4045
N343BS
Now in repair mode.
It is not a common thing to have happen in any engines. In Cosworth
blocks I did this mod just because the blocks cost as much as my house. I have
seen one fall out of a rotary, because pure water was left in over a winter.
It was a plug in the front iron and allowed water into the pan. The bearings
were lost and I got a rebuild job out of that one.
When replacing the plug with a new one, wire brush the anodize off of the
sealing sides of the new plug.
With a die grinder just break the outside corners of the hole.
Apply a thin coat of Non Hardening Permatex
gasket cement to the hole walls and outside of the plug.
Cover the plug with a piece of aluminum. Drive the plug in with a heavy,
slow moving hammer, to just flush.
You might think about adding two or three 8-32 or 10-32 threaded screw
holes around the edge of the hole and install a small washer that covers part
of the plug as shown. Use socket head screws and wire as shown. When you
overhaul an engine replace all of the plugs with new.
Lynn E. Hanover
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