TWIN CAM ENGINES

  Twin cam, 88 1450,  bore 3.750 strock 4.000
  Bath tub shaped ccombustion chambers
  3.7500 X 3.750 = 14.06 X 4.000 = 56.24 X .7854 = 44.17
  X 2 =88.34   88.34 X 16.39 = 1447.89
  1447 ÷ 2 = 723 + 85 Lcc head area + 11 Lcc head gasket
  area + 4 Lcc piston value pockets and piston- cylinder
  ring area and piston not flat with cylinder top.
  1447 ÷ 2 = 723 + 100 Lcc = 823 ÷ 100 = 8.23 to 1
  Harley manuel specification is 9-1 standard.
  If necessary deck head .010 at a time and recheck Lcc.
  Have value job done before necessary checking.
  The grinding of value and seats can add 1-2 Lcc to formula.
  Engine at different rpm will strech rod and pistons .040,
  if it happens it will just go into head gasket area.
  Average 1450 & 1550 stock gasket is .055 to .060 thick.
  Installed head gasket is a little less .005 to .010.
  Install HD adjustable pushrods and cover kit it will make the job easyier,
  and all lifter will have the same preload.
  Install S&S HL2T spacer in hydraulic lifter, spacers will stop lifter
  bleed down at high rpm and engine starting up easyier.
  Always use oil marked motorcycle oil.
 
 

TWIN CAM

  Twin cam 95  1550  bore 3.875 strock 4.000
  3.875 X 3.875 =15.02  15.02 X 4.000 =60.08  60.08 X .7854
  =47.19 X 2 =94.38,  94.38 X 16.39 = 1546.89
  1546.89 ÷ 2 = 773.45 + 100Lcc ÷ 100 = 8.73-1
                                              98Lcc ÷   98  = 8.89-1
                                              96Lcc ÷   96  = 9.06-1