Performance engine preparation Improving reliability Connecting rods tensile

Performance engine preparation Improving reliability Connecting rods • • tensile loads reduce reciprocating weight improve fasteners aftermarket rods

Performance engine preparation Improving reliability Pistons • light and strong • . 200” crown thickness • end gaps with hypereutectic pistons • coated piston skirts • effects of increased clearance? • more cam for less clearance

Performance engine preparation Improving reliability Rings • • frictional losses thin rings reduce friction Moly rings for less scuff and friction more end gap for second ring

Performance engine preparation Improving reliability Springs • • increased pressure increased strain on valve train parts friction dampers generate heat oil cools springs, but adds to consumption

Performance engine preparation Improving reliability Pushrods and rockers • • shafts are more stable than pivot balls pushrod guide plates stud girdles help stabilize rockers increased rocker ratios increase area under curve - also increase wear

Performance engine preparation Improving reliability OHC valve trains • some have rocker ratios • spring pressure much less than OHV

Performance engine preparation Improving reliability Oiling systems • larger pan, windage tray, baffles • high volume pumps to maintain pressure • volume up 5 x for 2 x increase in clearance

Performance engine preparation Improving reliability Bearing properties • corrosion resistance • strength • wear • embedability • conformability

Performance engine preparation Improving reliability Bearing materials • Babbitt Conventional – poor strength Thin – poor conformability & embedability • Sintered copper-tin-lead Poor corrosion resistance & wear Metal powders on steel backing

Performance engine preparation Improving reliability Bearing materials • Cast copper-lead Heavy duty applications Excellent strength & corrosion Other properties good • Non-overplated aluminum Wear & corrosion - good

Performance engine preparation Improving reliability Bearing materials • Overplated aluminum Uses silicon for durability Used by OEMs