Glossary “roll axis” Definition:
The longitudinal axis of a vehicle defined by an imaginary line running through the front and rear roll centers.
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roll bar
Glossary “roll bar” Definition:
A tubular bar behind the cockpit of a race car to protect the driver in case of a rollover.
roll cage
Glossary “roll cage” Definition:
A tubular, cage-like structure surrounding the cockpit of a race car to protect the driver in case of a rollover and to add strength to the overall structure of the vehicle.
rodding out
Glossary “rodding out” Definition:
When a radiator becomes plugged, this is done by a radiator shop to clean its cooling passages.
roll
Glossary “roll” Definition:
1). To turn over and over. 2). To tip or sway side-to-side. 3). The motion of a vehicle body toward the outside of a turn when cornering or changing directions suddenly.
rod journal
Glossary “rod journal” Definition:
Crankshaft journal the connects to the connecting rod.
rod length ratio
Glossary “rod length ratio” Definition:
The center-to-center length of a connecting rod divided by the piston stroke.
rod out
Glossary “rod out” Definition:
To clean a radiator, using a small rod to clean out the cooling passages.
rod ratio
Glossary “rod ratio” Definition:
Term used for the rod length ratio or rod-to-stroke ratio.
rod small end
Glossary “rod small end” Definition:
The end of the connecting rod through which the piston pin passes to connect the piston to the connecting rod.
rod bolts
Glossary “rod bolts” Definition:
Bolts used to secure the cap to the rod at the big end.
rod big end
Glossary “rod big end” Definition:
End of the connecting rod that attaches around the crankshaft.
rod bolt protectors
Glossary “rod bolt protectors” Definition:
Pieces of soft plastic or rubber used to protect the crankshaft from nicks during engine disassembly and reassembly.
rod bearing
Glossary “rod bearing” Definition:
Bearing at the crankshaft end of a connecting rod.
rod bearing journal
Glossary “rod bearing journal” Definition:
Parts of the crankshaft that the connecting rods attach to. They are also referred to as crankpins.
rod
Glossary “rod” Definition:
A steering arm or an engine connecting rod.
rocker arm geometry
Glossary “rocker arm geometry” Definition:
The angle of the rocker arm in relation to the valve stem. Rocker arm geometry is correct when the center of the rocker arm tip contacts the centerline of the valve stem when the valvetrain is at 30 to 50% of its maximum lift.
rocker arm ratio
Glossary “rocker arm ratio” Definition:
The difference between the upper movement of the pushrod, acting on one end of the rocker arm, and the downward movement of the rocker arm acting on the valve stem. Rocker arm ratio is usually around 1.5 to 1 (1.5:1).
rocker arm shaft
Glossary “rocker arm shaft” Definition:
A shaft in each cylinder head on which rocker arms are arranged and pivot..
rocker panel
Glossary “rocker panel” Definition:
Sheet metal along the bottom of an auto body, beneath the doors, and between the front- and rear-wheel openings.