Paccar 12.9 L

Paccar 12.9  2020

Cylinder Head

Short YouTube Video of Surfacing with CBN cutter 2020

Block liner counter bore machined for .25mm shims and .004/.007 protrusion 2020

 

Crankshaft balancing – non counter weight crankshaft style

Paccar 12.9 has no counter weights so we welded on the back rod in the factory balance holes.

Balance Weights   ROD    PISTON   ROD #

Piston kits 1834374

#1  10132 Grams  4784    5348         CY63

#2 10133 Grams   4807   5326         CY79

#3 10131  Grams  4789   5342         CY67

#4 10133 Grams   4801   5332        CY53

#5 10132 Grams   4800  5332         CY64

#6 10132 Grams   4784  5348        CY51

FINAL Balance on crankshaft

LEFT side 0.8 Oz/inches   RIGHT Side 0.8 Oz/inches  COUPLED 0.5 Oz/Inches

Crankshaft was RECEIVED at from the Factory

LEFT Side 5.5 Oz/Inches  RIGHT Side 3.5 Oz/Inches  (WAY OFF) Truck mirrors vibrated which is typical on Paccar 12.9 Truck motors and now no more vibrating!