How do you check bearing crush?
A procedure to check bearing crush is illustrated. Place shims of equal thickness (Ts) along both sides of the split lines. Lay a strip of plastigage or lead wire on top of the bearing shell along the shaft axis. Install the bearing cap or strap and tighten all split line bolts.
How do I know if I have big end bearing 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.
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.
What is a rod knock?
Rod knock is the sound of one or more of your rods “knocking” against the crank as it changes direction through its rotation. The connecting rod (we’ll just call it the rod from here out) is connected to the crank, and between the two there’s a bearing made from a softer material than either the rod or the crank.
How do you remove Plastigage from a bearing?
How do you remove Plastigage? “Ideally you should remove the PLASTIGAUGE stripe with a clean oily cloth or industrial de-greasing solvent, but users may be assured that any PLASTIGAUGE left behind is oil soluble and cannot harm the engine in any way”.
What is Plastigage made of?
PLASTIGAUGE is comprised of a rod or thread of a compliant plastic material of accurately determined cross-section – either circular or square. The surfaces between which measurement is to be made are first separated, PLASTIGAUGE is inserted (see fig. 2) and the surfaces are returned to their standard position.
How is crush fit determined for engine bearings?
To accurately determine crush fit, bearing manufacturers use a special block gauge to measure the bearing after it has been installed in a bore with a known size the cap has been torqued down to specifications. If crush fit is correct, the bearing will be held snugly in place without too much deformation that could cause clearance problems.
Why are the bearings on my big end engine worn out?
Big End engine problem – WORN OUT Pre maturely worn out bearings can be the result of dirty or diluted engine oil. When unsure and a cause must be established, take a sample of the used oil from the engine in a clean glass container and have it analysed. The result of the oil analysis will give definite answers to the cause of the failure.
What should I do if I have spun bearings in my engine?
If an engine has suffered a spun rod or main bearing, and the engine is rebuildable, it will require resurfacing the crank journal, possibly re-machining the main bore or big end rod bore (or replacing the rod) depending on the damage that has occurred.
How is the clearance of an engine bearing determined?
Just remember that bearing size needs to be uniform. Also, a general rule of thumb for determining oil clearance is .001 of clearance for every inch of shaft dia. Ex .001 x 2.00 shaft dia. = .002 oil clearance. Higher engine operating temperature, due to decreased oil flow Lower engine operating temp, due to increased oil flow