Valve head dia., intake valve .... 1.767 to 1.777 in 44.88 to 45.13 mm Model 2120 Tractor TM-4252 (Dec-70) Engine 20 Cylinder Head, Camshaft and Balancer Shafts 10-9 IMPORTANT! Make sure that the keyway of each balancer shaft gear is vertical to the cylinder head. If this is not the case, both shafts have been mixed up and must be reinstalled in the opposite bores. Install all engine and tractor parts removed to facilitate removal of balancer shafts (see removal). Valve stem dia. (standard) .................... 0.3715 to 0.3725 in 9.43 to 9.46 mm SPECIFICATIONS Dimensions of Wear Tolerance New Parts Clearance between bore and valve stem ...............
0.002 to 0.004 in 0.05 to 0.10 mm CYLINDER HEAD Valve stem oversizes, stem dia. larger than standard by ..................... 0.003; 0.015; 0.030 in 0.076; 0.381; 0.762 mm Bore for valve stem 0.3745 to 0.3755 in 0.001 in 0.025 mm 9.51 to 9.53 mm 0.006 in 0.152 mm Valve seat angle 45° Angle of valve faces 43.5° Concentricity tolerance of valve seat (max.) 0.002 in 0.05 mm Valve head dia., exhaust valve ................... 1.570 to 1.580 in 38.88 to 40.13 mm Valve seat width 0.057 to 0.073 in 1.45 to 1.85 mm Valve length ..........................
5.144 to 5.169 in 0.005 in 130.66 to 131.29 mm 0.13 mm Valve clearance Intake valve 0.014 in 0.35 mm Exhaust valve 0.018 in 0.45 mm Printed in Germany