Available Installation and Alignment Instructions
Allowance for Expansion due to Thermal Growth
Cast iron has a thermal expansion coefficient of 0.0000066 in. per in. per Degree F (0.000012 mm per mm per Degree C). Steel has an average thermal expansion coefficient of 0.0000063 in. per in. per Degree F (0.000011 mm per mm per Degree C).
The engine mounting system must allow for this expansion through the proper use and placement of clearance bolts, fitted bolts, and dowels. Failure to allow for thermal expansion will result in driven equipment misalignment and engine block distortion.
Compensation offsets must be incorporated into alignment procedures to accommodate this growth when alignment is performed cold.
Thermal expansion = Expansion Coefficient × Linear Distance* × Delta T
*Linear distance is the length or width of engine for horizontal growth and the distance between the mounting surface and the crankshaft centerline for vertical growth.
Examples: 3606 - Cast Iron Block, Length of block between rear fitted bolt and front clearance bolt in 87.6 in. (2226 mm). Delta T = 130°F (72°C). Expansion allowance required is:
0.0000066 (0.000012) × 87.6 in. (2226 mm) × 130°F (72°C) = 0.075 in. (1.9 mm)
Collision Blocks for Marine Engines
When marine classification societies or local marine practice requires the use of collision blocks, they should be located with sufficient clearance to allow for thermal growth of the engine. Prefabricate the collision blocks and install them while the engine is at operating temperature with approximately 0.005 in (0.12 mm) hot clearance. Collision blocks are recommended to resist the shock loads encountered in hard docking collisions and groundings.
Types of Misalignment
Parallel or bore misalignment occurs when centerlines of driven equipment and engine are parallel but not in the same plane.
Angular or face misalignment occurs when centerlines of driven equipment and engines are not parallel.
Dial Indicator Quick Check
When both shafts are rotated together, the algebraic sum of the readings at D and B should equal the reading at C. This check is useful for identifying improper indicator setup or procedure. The example shown is out of alignment.
Required Foundation Depth for Stationary Installations
Calculate foundation depth to equal generator set weight by:
FD = foundation depth in feet (meter)
W = total wet weight of generator set in pounds (kg) Use 125% of actual weight if vibration isolators are not used.
D = density of concrete in pounds per cubic foot (kg/m3)
NOTE: Use 150 for English unit and 2402.8 for metric unit.
B = foundation width in feet (meter)
L = foundation length in feet (meter)
Pressure on Supporting Material
Where: P = Pressure in psi (kpa)
W = Weight in pounds (kg)
A = Area in square inches (m2)
Pressure imposed by the generator set weight must be less than the load-carrying capacity of supporting material.
General Torque Specifications
The following charts give general torque values for fasteners of SAE Grade 5 or better and Metric ISO Grade 8.8.
Torques for Bolts and Nuts with Standard Threads
Torques for Taperlock Studs
Metric ISO Thread