22844848 Volvo.Penta Sprocket

Height Of The Piston Above The Cylinder Block
Table 1
Required Tools
Part Number Part Description Qty
8T-0455 Liner Projection Tool Group 1 If the height of the piston above the cylinder block is not within the tolerance that is listed in the Specifications Module, "Piston and Rings", the piston and the bearing for the piston pin must be replaced. If any of the following components are replaced or remachined, the piston height above the cylinder block must be measured:
Crankshaft
Cylinder head
Connecting rod
Bearing for the piston pin
PistonThe correct piston height must be maintained in order to ensure that the engine conforms to the standards for emissions.Note: The top of the piston should not be machined. If the original piston is installed, ensure that the original piston is assembled to the correct connecting rod and installed in the original cylinder.Six grades of length of connecting rods determine the piston height above the cylinder block. The grade of length of a connecting rod is identified by a letter or a color. The letter or the color is marked on the side of the connecting rod. Refer to "Inspection Of Connecting Rods" for specifications of the connecting rods.
Illustration 1 g00323908
8T-0455 Liner Projection Tool Group
(1) 1P-2403 Dial indicator
(2) 1P-2402 Gauge body
(3) 1P-5507 Gauge block
Use the 8T-0455 Liner Projection Tool Group in order to measure the piston height above the cylinder block. Use the gauge block (3) to zero the dial indicator (1) on the face of the cylinder block.
Position the gauge block (3) on the cylinder block. Rotate the crankshaft until the piston is at the approximate top center. Ensure that the flame ring of the cylinder liner does not interfere with the gauge block or the dial indicator.
Illustration 2 g00326383
Measurement of the piston height
(1) 1P-2403 Dial indicator
(2) 1P-2402 Gauge body
Position the gauge body (2) and dial indicator (1) in order to measure the piston height above the cylinder block. Slowly rotate the crankshaft in order to determine when the piston is at the highest position. Record this dimension. Compare this dimension with the dimension that is listed in the Specifications Module, "Pistons and Rings". Inspection Of Connecting Rods
These procedures determine the following characteristics of the connecting rod:
Length of the connecting rod
Distortion of the connecting rod
Parallel alignment of the bores of the connecting rodNote: If the crankshaft or the cylinder block are replaced, the piston height for all cylinders must be measured. The grade of length of the connecting rods may need to be changed in order to obtain the correct piston height. If the grade of length must be changed, one of the following actions must be taken:
New connecting rod assemblies that are the correct grade of length must be installed. Refer to "Length Of A Connecting Rod".
New piston pin bearings must be bored after installation in the original connecting rods. Refer to "Piston Pin Bearings".Note: When the piston pin is installed, always install new retaining rings on each end of the piston pin. If the piston pin cannot be removed by hand, heat the piston to a temperature of 45 ° 5 °C (113 ° 9 °F) in order to aid the removal of the piston pin. Heating the piston to this temperature may also aid the installation of the piston pin. There is a recess on the face of the connecting rod. The recess is for the piston pin. The recess must always face the same side as the bore for the journal bearing.Length Of A Connecting Rod
CRL is the length of the connecting rod. Refer to Table 2 for each grade of length of connecting rod.In order to ensure that the piston height above the cylinder block is correct, six grades of length of connecting rods are used. The grade of length is identified by a letter or a color which is marked on the side of the connecting rod. The longest grade is marked with the letter "F". The shortest grade is marked with the letter "L". The difference in length between each grade of connecting rods is the following value: 0.046 mm (0.0018 inch)The grade of length of a connecting rod is determined in the factory by machining an eccentric hole in a semi-finished piston pin bushing. Therefore, the grade of length is determined by the position of the center of the hole in the piston pin bearing. There is a hole that is in the connecting rod for the piston pin bearing. The grade of length is not determined by the position of the hole that is in the connecting rod for the piston pin bearing.If the connecting rod must be replaced, a new connecting rod assembly must be purchased and installed. Refer to Table 2 for more information. A new piston pin bearing is installed in the new connecting rod at the factory. The bore of the piston pin bearing is reamed to the correct eccentricity.Piston Pin Bearings
Note: This procedure requires personnel with the correct training and the use of specialized equipment for machining.If the piston pin bearing requires replacement but the original connecting rod is not replaced, the following procedures must be performed:
Determine the grade of length of the connecting rod. Use one of the following characteristics:
The mark
The color
Measuring the lengthNote: The length of the connecting rod is measured when the following items are completed: Remove the bearing for the crankshaft journal. and Install the original piston pin bearing in the connecting rod. Refer to "Measure The Length Of A Connecting Rod".
Ensure that the connecting rod is aligned parallel and that the connecting rod is not distorted. Refer to 4 in this module.
Remove the piston pin bearing from the connecting rod. Install a new bearing in the connecting rod. The new bearing is partially finished. The new bearing must be bored off-center to the correct diameter. This off-center position is determined by the grade of length of the connecting rod. Refer to Table 2. The correct diameter of the bore in the piston pin bearing is found in the Specifications Module,