Metrology for Gasoline and Diesel Engine Lubricants Research

To help industry develop engine oils and lubricants to meet current and future requirements and challenges, Southwest Research Institute (SwRI) conducts detailed studies of used and failed engine parts. The Institute uses state-of-the-art metrology equipment and skilled technicians to meet industry requirements for rapid, precise, and reliable data.

Surface Analyzers

The Fuels and Lubricants Research Division uses surface analyzer technology in a variety of programs. One instrument uses laser interferometry to determine how varying component forms and surface textures affect fuel and lubricant performance in heavy-duty diesel engines. Components studied include piston rings, pistons, and cam lobe profiles. The staff obtains detailed data about surface texture variations in heavy-duty diesel engine cylinder liners and in preselected areas of the liner bore surface.

Researchers statistically assess liner bore surface texture variations.

Ring belt gas flow dynamics play a significant role in oil consumption. Using the Form Talysurf, SwRI assesses form and surface finish to calculate associated gas flow areas and estimate gas flow characteristics.

Surface analyzers are also used to study the piston rings from heavy-duty diesel engines. The Institute obtains detailed information about the form, profile, and surface texture of the ring face contacting the cylinder bore surface.

Ring Tension Machine

The Institute's Ring Tension Machine precisely measures piston ring tension in pounds-force at a preselected piston ring end gap. Using these measurements, SwRI attempts to ensure the consistency of oil consumption and blowby in heavy-duty diesel engines. The Sequence VI Fuel Efficient Engine Oil test utilizes this machine to document piston rings precisely during engine building. Ring tension is a major contributor to engine friction, so the correct combination of ring tensions is critical.

Federal Formscan®

The Institute measures roundness, concentricity, eccentricity, circularity, parallelism, and squareness of a variety of connecting rods, pistons, rings, and wrist pins with the Federal Formscan® 300 Geometry Gage. This device will also produce single diameter traces or digital-only readings without polar traces.

Using the Federal Formscan® gage, SwRI measures the form characteristics of a variety of parts for gasoline and diesel engine lubricant tests.

Coordinate Axis Measuring Machine

The CS Series Coordinate Axis Measuring Machine features a self-contained system providing dimensional inspection of new or used parts ranging from a few inches in size to very large engine or vehicle components. Part features, angles, distances, and forms are measured to a resolution of 0.00002 inch with repeatability to 0.00008 inch. The system is operated entirely by a computer touch screen. A stylus directly mounted into a probe produces a trigger signal when it contacts the components, producing exacting measurements. Successful component gaging depends on the stylus accessing a certain feature and maintaining accuracy at the point of contact. The size and type of stylus used depends on the component and features to be inspected. The Institute uses a variety of styli for the myriad of measurements made for Gasoline and Diesel Engine Lubricants Department projects.

The Institute's computerized Coordinate Measuring Machine facilitates the dimensional inspection of components.

Video-Scope Microscope

The Video-Scope Microscope combines a powerful microscope with an attached camera, video scope, and printer. The SwRI staff uses this device to check liners for surface scratches, cracks, and pitting. Research includes studying the effect and correlation of blemished liners and oil consumption. Images seen through the microscope can be printed instantaneously.

Geotze Keystone Angle Measuring Instrument

The Institute uses this instrument to measure piston ring keystone angles -- the angles enclosed by the two sides of the ring -- in accordance with ISO 621/2. A foot switch pneumatically positions the piston ring, and two measuring heads move up against the keystone side face. Two integral, inductive measuring probes separately measure the top and bottom keystone angles, and deviation, in minutes, from the gauge ring is digitally displayed. With the Goetze instrument, SwRI also performs 100 percent inspections by integral classifier units. Five different displays are available.

A Goetze Keystone Angle Measuring Instrument produces rapid measurements of the keystone angle of piston rings.

Additional Services

For complete characterization of components, the Institute uses a wide variety of facilities and equipment, including:

• J&L Epic-30 Optical Comparator
• Suntronic 3P Portable Surface Measurement Machine
• Unitron Series TM Measuring Microscope
• Dermitron Model D-5 Coating Measurement Apparatus
• Sturtevant Richmont Digital Torque Wrench Analyzer
• Cam Doctor Cam Profile Measurement Apparatus
• Sunnen AG-300 Precision Gage for Rod Reconditioning
• Raymond Engineering Bolt Gage II
• Rockwell Hardness Tester

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