Mercury MERCRUISER - Cylinder Bore; Engine Specifications; Oil Pump; Piston Bore Clearance

Description Specification
Block Cast iron (two bolt main bearing caps)
Rods Forged steel
Crankshaft Forged steel
Pistons Cast aluminum
Camshaft Steel
Intake manifold Aluminum
Engine Specifications
Cylinder Head
Description 6.2 Liter (377 cid)
Surface flatness
At exhaust manifold deck 0.05 mm (0.0020 in.)
At engine block deck with
an 150 mm (5.90 in.) area
0.05 mm (0.0020 in.)
At intake manifold deck 0.10 mm (0.0039 in.)
Intake manifold flatness 0.10 mm (0.0039 in.)
Cylinder Bore
Description 6.2 Liter (377 cid)
Diameter 101.009–101.018 mm (3.976–3.977 in.)
Out of round
Production 0.012 mm (0.0005 in.) maximum
Service 0.05 mm (0.0020 in.)
Taper
Production—thrust side 0.012 mm (0.0005 in.) maximum
Production—relief side 0.025 mm (0.0010 in.) maximum
Service 0.025 mm (0.0010 in.) over production
Oil Pump
Description Height
Oil pump dowel pin 8.067–9.683 mm (0.3175–0.3812 in.)
Piston Bore Clearance
Description 6.2 Liter (377 cid)
Production 0.055–0.083 mm (0.0022–0.0032 in.)
Piston Rings
Top Compression
Description 6.2 Liter (377 cid)
Groove clearance Production 0.030–0.075 mm (0.0012–0.0029 in.)
Gap Production 0.38–0.52 mm (0.015–0.020 in.)
Second Compression
Description
6.2 Liter (377 cid)
Groove clearance Production 0.020–0.060 mm (0.0008–0.0023 in.)
Gap Production 0.63–0.82 mm (0.025–0.032 in.)
Engine Inspection and Assembly
90-8M0099748 eng DECEMBER 2015 © 2016 Mercury Marine Page 3B-3