Plastigage MPB1 For Measuring .004 to .009 Clearances

• Clearance measuring tool
• Flattens precisely to give a quick and accurate way to check Main and Rod bearing clearances
• For measuring 004 to .009 clearances
• Specially formulated oil soluble plastic material
• Blue
• Sold Each.   12 per case

Plastigage can be used as a quick way to check clearance. To use plastigage correctly, first assemble the upper bearing shell into the housing, then install the crankshaft. Lay a strip  of plastigage lengthwise across the center of the bearing journal.

Install the lower bearing shell and cap, and tighten the fasteners to the specified torque. Loosen the bolts and
remove the bearing cap and lower shell, being careful not to rotate the crankshaft. Compare the thickness of the now compressed plastigage strip to the chart on its package to determine the bearing clearance. Carefully remove all traces of plastigage from both the  crankshaft journal and the bearing before final assembly.

High performance engine applications may require different bearing clearances than unmodified engines. Many engine builders target a clearance range between .0022" and .0027". Clearances greater than .003" are not normally recommended. Some engine builders like higher oil pressures than a standard oil pump can provide, particularly at lower engine
speeds. Large bearing clearances will lower oil pressure, and may require a high volume oil pump. An engine should maintain a minimum oil pressure of 10 lbs. per 1000 RPM.

Plastigage is also used by machine manufacturing for checking clearances.  Pumps, Generators, Industrial equipment of all kinds can be checked using this procedure.  Also used in the injection mold businesses.