ACL Duraglide bearings
ACL supplies an extensive range of automotive engine bearings for niche applications and the aftermarket worldwide. Although ACL manufactures several different materials to suit various applications, tri-metal copper lead DuraglideTM F780 is considered to be the premium material and is used extensively in many aftermarket applications.
The material provides the widest range of load carrying capacities with excellent durability, making it ideal for connecting rod and main bearings in passenger cars using gas and diesel, and high performance engines.
ACL DuraglideTM F780 bearings are a rugged solution to a rugged problem. Engine re-builders face an increasingly diverse range of engines with a variety of OEM bearing types. While these OEM bearing types and materials may be well suited to engines finished to modern engine manufacturers' exacting specifications, they are frequently unsuitable for used engines reconditioned and rebuilt in a flexible workshop.
The ACL F780 tri-metal material system, which is at the heart of Duraglide 780 bearings, was designed for and proven in a wide range of engine applications, both OE and aftermarket. The complementary layers ensure that the steel and sintered copperlead-tin lining provide superior strength, while the lead-tin-copper overlay provides excellent anti-seizure properties. This means confidence for the engine rebuilder – confidence provided by a tough bearing capable of high performance whether installed in a garage or precision workshop.
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1 - The lead-tin-copper overlay used by ACL is composed of approximately 90% lead, 9% tin, and 1% copper. For most automotive applications, overlay thicknesses range from.0005′′ to.0007′′. TM 2 - A lead-tin-copper overlay is applied to ACL's copper-lead-tin bearings. However, a nickel intermediate layer (barrier plate or dam) is required to maintain the overlay's optimum metallurgy under all operating conditions. ACL's superior quality construction and electroplating control eliminate the possibility of overlay flaking. 3 - ACL sintered copper-lead-tin alloys have a tough structure that can withstand high compressive loads while also providing excellent adaptability. 4 - Steel strip with powdered copper-lead-tin metal alloy applied. To bond the alloy to the steel backing, the strip is sintered and compressed. |
| Bearing Type Characteristic | DuraglideTM F780 |
| Strength Ability to assume prolonged, high fatigue loads. |
Babbitt overlay (<20HV) is supported by a strong copper lead alloy (>50HV) in turn supported by the steel backing. Strength is high as long as the overlay is thin (<.0008″). |
| Anti-Seizure Conformability Ability to adapt to assembly and misalignment errors. |
Very soft Babbitt overlay readily adapts. Copper lead alloy has moderate conformability and helps to adapt where shape errors are significant. |
| Compatibility Ability to accommodate shaft to bearing contact through thin oil films. |
Crankshaft journal finish is the dominant factor. Contact with the surface results in adaptation through wear of the Babbitt layer with no damage to the shaft. |
| Emergency Running Ability to continue operation during temporary oil film breakdown. |
The lead in the Babbitt and copperlead alloy has natural lubricity and can function as a dry lubricant. The low melting point on the alloy also allows it to provide a temporary liquid lubricant. |
| Anti-Wear Resistance to abrasion by shaft and dirt. |
Babbitt alloys are prone to wear (see above), however the alloy composition is carefully controlled to optimise the strengthening effects of copper and minimising the wear potential. |
| Embeddability | The soft Babbitt readily absorbs all kinds of dirt particles up to .0006″ without damage. Larger particles are adequately accommodated by the underlying layers. |
| Anti-Corrosion | Tin content in both the lining and overlay alloys provides protection from chemical attack. |
| Applications | DuraglideTM bearings provide a high combination of high strength and the ability to withstand harsh and demanding operating conditions. This makes them ideal for performance engines and rebuilds. |
source: aclraceseries.com