BY CLARENCE LEE
Fixes for Troubled Engines
As regular followers of “Engine Clinic” will
most likely know, the January issue always
marks a milestone in the writing of this
column, the first having appeared in the
January 1969 issue of the now out of publication, R/C Modeler. In the summer of 1968,
I was approached by R/C Modeler asking if
I would be interested in writing a column
about engines, particularly to answer reader’s questions. It seems that the magazine
was receiving a considerable number of
engine-related inquiries that they did not
feel qualified to answer. I decided to give
it a try and here we are, starting the 45th
year of writing the column— 36 years with
R/C Modeler before they ceased publication
and seven years now with Model Airplane
News. When R/C Modeler went out of business, I had about decided to quit magazine
writing even though I had had offers from
two other modeling publications. Then
I received a phone call from the executive editor of Model Airplane News, who
convinced me to keep the column going.
The ideas for subjects and topics does run
pretty thin at times, but fortunately, some
of our readers will usually come through.
So remember guys, it is our readers’ letters
that keep this column going. If you have
an engine related problem, send it in. And
now, to our letters.
Introduced in 1982, the O. S. Wankel was a true three-lobe rotary design.
of wood. It may take a couple of reheating
treatments, but the bearing will come out.
The front bearing can be tapped using a
short length of aluminum or brass rod and
small hammer. Any defective parts can be
ordered from hobby services that service
the O.S. line of engines. Good luck.
U Perhaps you can help me. I have an
O.S. rotary engine that has run very well
and was installed as a pusher last summer
and appeared to overheat. I removed the
engine immediately but apparently not fast
enough. The engine has lost compression
and feels rough when turned over. I love
this little miracle and need information on
how to properly disassemble and rebuild it.
I have the parts list and “exploded view,”
but no information on how to remove the
shaft, etc. Also, what is a good source for
Bill, rebuilding your Wankel rotary can
be very simple or complex depending on
what damage has occurred. The engine
has a three-lobe rotor with spring-loaded
blades on the tips (see drawing). They
could just be stuck, or the spring tension
on the blades has been lost due to the over-
heating. This would just require freeing up
the blades or replacing the springs. How-
ever, this would not explain the rough-
ness that could be more serious. Without
being able to examine the engine, I cannot
say whether this is caused by a bearing or
something else. The fit of the rotor between
the front and back covers is very critical. If
scoring has occurred, you have a problem
that could be pretty expensive to repair.