WHITE METAL BEARINGS

Guaranteed Fault Free For Life

Formhalls Vintage & Racing Ltd are worldwide suppliers of White Metal Bearing services to the restoration industry, engine manufacturers, Museums, machine shops, racers & private enthusiasts. All our bearings come with a lifetime guarantee against casting and material faults for the life of your engine.

What Are White Metal Bearings?

A white metal bearing is a soft, anti-friction layer bonded to a hard backing of bronze or steel. Its purpose is to protect your crankshaft by allowing fine abrasive particles in the oil to embed below the surface, preventing crankshaft wear.

These bearings offer excellent resilience, absorbing high momentary overloads (such as during oil surge), and they adapt to minor misalignments—helping to avoid sudden failure. Even though oil cleanliness is important, white metal bearings are generally more forgiving than other bearing types.

One set of our bearings has completed over 60,000 miles of competitive driving—a testament to their durability

The Importance of a Proper Bond

For a bearing to perform correctly, the white metal must be uniformly bonded to its backing shell. If oil seeps between the lining and the shell, it creates an insulating layer, disrupting heat transfer and risking failure.

We use several proven methods to verify bond integrity:

  • Ring Test
    Tapping the bearing and listening for a dull tone, which may indicate poor bonding.
  • Dye Penetrant
    A two-step dye system that can highlight surface cracks or defects.
  • HOYT Bondmeter
    Our preferred method. It measures electrical current through the shell to detect weak bonding areas.

The Formhalls Bearings Process

  1. Crankshaft Inspection – We begin every job by inspecting the crankshaft for cracks, straightness, and wear. If required, we grind and polish the journals to the minimum necessary tolerance.
  1. Housing Preparation – Main bearing housings are checked for contact and nip using marking blue and feeler gauges. Ovality is measured—if it exceeds 0.010″, we recommend line boring and producing new bearing backs.
  1. Shell Preparation & Casting – The bearing shells are stripped of old white metal and cleaned. We use only new Hoyt 11R or 11Z3 white metal ingots. Shells are tinned, and the moulds and pots are preheated to ensure uniform temperature. Metal is poured and left to cool naturally.
  1. Rough Machining & Fitting – After casting, bearings are:
  • Cleaned and drilled
  • Rough bored and grooved
  • Carefully fitted to the housing, with nip adjusted using feeler gauges
  1. Final Line Boring – The block is mounted on a specialist line boring machine and aligned with the main tunnel. Bearings are machined in incremental steps down to 0.0005”, ensuring a perfect, scrape-free fit to the crankshaft. Once complete, bearings are de-burred and trial fitted.

Need Advice?

Whether you are planning a complete rebuild, exploring bearing suitability for a rare application, or need support with machining or redesign—we are here to help.

Contact us today at Formhalls for expert guidance on your white metal bearing requirements.

Call: 01725 511241
E-mail: enquiries@formhalls.com

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