The  crankshaft  had  four  throws  and  was  supported  in
three  ball  bearings.  Opposite  cylinders  in  the  Vee  were
staggered,  hence  the  use  of  side-by-side  connecting  rods  was
permitted.  The  pistons  were  cast  from  iron  and  fitted  with
four  eccentric  rings.
Forced  lubrication  was  provided  by  a  gear  pump,  and  the
cooling  water,  whcih  was  circulated  by  a  rotary  pump,  entered
the  cylinders  at  points  just  outside  the  exhaust  valves.  Dual
ignition  was  furnished  by  two  high-tension  single-spark  mag-


Fig.  436.    End  View  of  Snadecki  Engine.
Airplane  Engine  Encyclopedia


Fig.  437.    Side  View  of  Snadccki  Engine.
netos,  and  the  mixture  was  supplied  by  two  Schebler  carbu-
retors. The  overall  dimensions  of  the  engine  were  as  follows :
leng^th  53.5  in.,  width  37.5  in.,  and  height  39,625  in.
S.  P.  A.
The  Societa  Piemontese  Automobili  of  Turin,  Italy,  be-
gan building  airplane  engines  in  1908.  The  first  engine  was
a  25-h.p.  two-cylinder  opposed  type  operating  two  propellers.
Another  air-cooled  opposed  type  that  developed  90  h.p.  was
constructed  with  eight  cylinders,  and  there  was  also  an  eight-
cylinder  engine  of  the  water-cooled  Vee  type.  In  1915  the
company  built  a  ten-cylinder  radial  design.
In  1916  the  plant  was  enlarged  for  manufacturing  the
S.  P.  A.  6-A  type.  This  engine  has  also  been  built  by  Ansaldo
San  Giorgio,  Breda,  Talomona,  and  the  Industrie  Mecchaniche
e  Ferroviarie  of  Arezzo.  The  6-A  engine  was  built  in  three
types,  the  normal,  semi  super-compressed,  and  the  super-com-
pressed.
Type  6-A  Normal.  The  S.  P.  A.  6-A  engine  is  a  six-
cylinder  water-cooled  vertical  type  of  135  mm.  (5.31  in.)  bore,
170  mm.  {6.69  in.)  stroke,  and  a  total  displacement  of  888.9
cu.  in.  This  engine  is  rated  150  h.p.  at  1600  r.p.m.  and  weighs
562  lbs.,  or  3.74  lbs.  per  rated  h.p.
