Engine & Transmission Tips • Issue 44

Fraser Manufacturing

Part 2 - A Closer Look At The Cylinder Head

Details Are Critical In Refurbishing A Cylinder Head

UTH Cylinder Head AS180771193In this second installment of our three-part series on the new Fraser Manufacturing services, wer are going to continue detailing our engine remanufacturing process by taking a closer look at our cylinder head refurbishing process.

The cylinder head, often referred to as the “head” is located on top of the engine block, and closes in the cylinders below, in the case of a “V” engine, there are two cylinder heads. The cylinder head provides passages, or ports, that feed fuel and air to the cylinders, and allows exhaust to escape after combustion. The head commonly provides mounting for valves, spark plugs and fuel injectors.

The most common problems with cylinder heads is cracking, which is a direct result of engines overheating. A cracked cylinder head can cause a multitude of other problems like coolant leaks, oil leaks, loss of engine power, and ultimately an engine rebuild.

As we noted in the overview, (Part 1), Fraser’s remanufacturing process focuses closely on restoring all engine parts, including the cylinder heads, back to their best possible performance state. 

This remanufacturing involves the cylinder head’s disassembly, cleaning, diagnostic testing, and refurbishment.

The first step is the removal of the cylinder head from the engine block. Over time, all engine parts accumulate carbon and sludge build-up, as well as remnant engine oil and coolant. All of these contaminants are removed throug a series of scrubbing and high-pressure washing. Once fully cleaned, the head is inspected for pits and cracks. No matter how hairline, Fraser will use a high-heat epoxy to fill any openings in the head. If applicable, the camshaft is also processed, including a fine measurement to ensure tolerances are to spec.

All parts associated with, or installed on, the head are also closely examined, including rocker arms, valve guides, and studs. Should any issues be found, the part is replaced.

Some cylinder heads require more attentions than others, due to excessive wear. In these cases resurfacing by flat grinding or milling is done. This removes a layer of the cast iron on the side of the head that meets the engine block, allowing the new head gasket to seat perfectly, providing a better seal and higher compression. Fraser uses the industry standard Roughness Average (Ra) specification for this process.

Again, in certain cases, Fraser provides highly-specialized grinding for specialty cylinder heads, but milling with polycrystalline diamond tools is a faster, and more consistent process for refurbishing the head contact service.

After all of the tooling, the head is cleaned once again, and reassembly begins with the valves being installed and tested for position and operation. Once the entire head is complete, it is re-mounted on the engine block

Fraser Manufacturing is proud to focus so intensely on the rebuilding of our engines. It is our goal to repair or replace every single part to return the engine to OEM (original equipment manufacture) tolerances, or better.

We believe Fraser Manufacturing’s attention to details in the reconditioning process saves our customers money by the improvements we make to the engine, which improves performance, reduces fuel waste, and increases the life of the engine.


Fraser manufacturing Logo

Summary of Fraser Manufacturing services offered:

  1. Full Engine Remanufacturing
  2. Engine Boring and Honing
  3. Precision Machining
  4. Cylinder Head Resurfacing
  5. Cylinder Head Seat Grinding
  6. Crankshaft Reconditioning, Grinding and Polishing
  7. Camshaft Welding, Grinding and Polishing
  8. Cleaning by Magnaflux, Ultrasonic and Hot Tank

To contact Fraser Manufacturing, call 800-731-3177, extension 120.


Fraser Engine Rebuilders specializes in remanufactured engines. Any diagnostic computers in your car will operate exactly the same with our products. Visit our home page to find the right engine, if yours is ready to retire. They’re less expensive than you might think and come in different options and warranties!

Thinking about building a replica with an american-made engine? Fraser has the right engine ready for you!