How do you adjust rod bearing clearance?

The commonly accepted rule that most crankshaft manufacturers prefer for street and performance engines is 0.0010-inch for every 1-inch of journal diameter. So for a 2.45-inch small-block main journal, the bearing clearance would be 0.0024-inch.

What kinds of problems can increased rod bearing clearance cause?

The oil light on the dashboard may illuminate due to low oil pressure caused by a loose rod bearing, leading to increased clearance between internal engine parts. The check engine light may also illuminate.

What would happen if main bearing clearance is too loose?

Too little clearance and you’ll have trouble keeping your oil temperatures in check, and a spun bearing is much more likely. On the other hand, if the tolerance is too loose you hemorrhage oil out from around all the bearings.

Why do engine bearings have clearance and what happens if the clearance is too much or too little?

Higher pressure comes from greater resistance, while lower pressure is the result of less resistance. When it comes to bearing clearances and their effect on oil pressure, a looser clearance will reduce flow resistance and lower the oil pressure.

How accurate is Plastigage?

Tech Tip: Be sure to always use the inch side of the Plastigage package. Most good micrometers will measure down to 0.0001 inch (one ten-thousandths of an inch), which is plenty accurate. Our mic and dial-bore gauges came from Powerhouse.

How do you measure connect rod clearance?

For these reasons, bearing clearances are specified as “vertical clearance” and must be measured at 90 degrees to the split line. The best method of measurement is with a dial bore gage that measures the bearing inside iameter when the bearings are installed at the specified torque without the shaft in place.

What is normal clearance of bearing?

Radial bearing clearance is broken down into several groups: C1, C2, CN, C3, C4, and C5. CN is the “normal clearance” and is defined by DIN 620 and ISO 5753 and is used for bearings in normal operating conditions; C1 and C2 class bearing have radial clearances smaller than CN.

How do you check Plastigage bearing clearance?

Tear off a piece of plastigage. Open the paper to remove the plastigage, and place the plastigage across the surface of crankshaft. Position the plastigage in the center of the journal surface. Install the bearing cap and torque the bolts to specification.

How long is Plastigage good for?

Shelf-life: 3 years. Plastigauge is manufactured in the United Kingdom.