I  rarely  turn  my  motor  more  than  6500rpms, shift  at  6000rpms....It  was  recommended  to  freshen  the  motor  up  at  least  every  30 hrs., I  just  never  got  around  to installing  an  hour  meter, too  busy  running  the  car  I  guess, so  my  estimate  of  40 to  50  hours  is  just  that,an estimate, but  I  think  it  is  pretty  close  to  the  actual  running  time....
I  did  install  an  hour  meter  just  before  I  pulled  the  motor,had  it  in  the  car  for  the  last  race  of  the  season, just  to  make  sure  it  works  properly, put  1.3  hours  of  running  time  for  one  day  race, normal  for  a  race  for  me........
From  now  on, it  will  come  out  every  30  hours  at  the  longest,unless  I  have  a  problem, hopefully  not....this  time, it will  get  new  cylinder  heads, rings,bearing, afterwards  I plan  to  change  out  the  valve springs  every  other  time....I  change  the  
oil  every  other  race, that's  11  quarts  of  20/50  Mobil 1  and  an  HP  
oil  filter, runs  about  me  about 70 bucks....need  an  
oil/fuel  sponsor..
 
  
  
 
  a  tire  sponsor  would  also  be  nice....
 
  
  
  
 
David