Type  X.  One  of  the  latest  Clerget  developments  is  a  six-
teen-cytinder  water-cooled  "X"  type  engine  rated  at  400  h.p.
The  bore  and  stroke  are  130  mm.  (5.12  in.),  and  the  total  dis-
placement is  1685.44  cu.  in.  The  rated  output  is  developed
normally  at  1550  r.p.m.  and  420  h.p.  at  1600  r.p.m.  The  fuel
consumption  is  stated  to  be  .567  lbs.  per  h.p-hr.,  and  the  oil
consumption  .06  lbs.  per  h.p-hr.  The  dry  weight  is  reported
to  be  770  lbs.,  or  1.92  lbs.  per  rated  h.p.  The  approximate
overall  dimensions  are  as  follows:  length  52  in.,  width  39  in.,
and  height  39  in.
Twin.  A  two-cylinder  air-cooled  horizontally  opposed
engine,  recently  marketed  for  use  in  small  single-seater  sport
planes,  is  rated  at  10  h.p.,  but  said  to  develop  16  h.p.  The  bore


Fig.  12].    The  Clerget  Two-Cjrlinder  Air-Cooled  Engine


130


Airplane  Engine  Encyclopedia


is  85  mm.  (3.25  in.),  the  stroke  100  mm.  (3.94  in.),  and  the
total  displacement  69.46  cu.  in.  The  engine  is  reported  to
weigh  48.5  lbs.
The  cylinders  with  cooling  fins  are  machined  from  steel
forgings.  The  valves  are  situated  in  the  -cylinder  head  and
operated  by  means  of  push  rods  and  rockers.  Roller  bearings
are  used  for  the  crankshaft  and  the  big  end  of  the  connecting
rods,  and  the  pistons  are  cast  from  aluminum.
CLEVELAND

The  Cleveland  engines,  designed  by  Walter  C.  Willard,
were  water-cooled  barrel  types  planned  so  that  many  of  the
same  parts  could  be  used  on  a  number  of  sizes  ranging  from
100  to  600  h.p.  The  Model  4  herein  described  was  rated  at  150
h.p.  This  was  a  six-cylinder  engine  of  5  in.  bore,  6  in.  stroke,
and  706.86  cu.  in.  total  displacement.
Fig.  122.    The  Cleveland  Aero  Engine.
