Cylinder Head Skimming

Our extensive machine shop facilities and experienced technicians enable us to repair any cylinder head for any vehicle. We can, skim, weld or completely recondition your cylinder head usually by next day.

Cylinder Head Services:

Cylinder head washing, pressure testing of all cast and alloy heads, skimming of all cast and alloy heads, refacing valve seats and valves, setting up valve clearances – shimming, removing of Glow plugs, broken stud extraction and thread inserting, weld repair of alloy heads, removing of broken bolts, removing of injectors, etc.

Pressure Testing Of Cylinder Heads

The cylinder head sits above the cylinders on top of the engine block. If your engine has overheated or had a cooling system failure it could cause the cylinder head to be warped/distorted or cracked.

We always suggest that you have the cylinder pressure tested for cracks before you do any form of repairs. Some cracks can be repaired and some will be irreparable. It would be a waste of your money to pay for repairs to a cylinder head and then when the mechanic fits it back up to the engine you discover that there is still some form of leaking or power loss due to an internal crack. Once your cylinder head is removed we would always recommend a pressure test as a cracked head can be the cause or a symptom of overheating.

When we pressure test a cylinder head we are looking for any internal or external leaks. We do this by blocking the water outlets on the cylinder head and then pressurising the cylinder head with compressed air at 40psi. We would then confirm if the cylinder head is leaking.

Due to the constant thermal expansion and contraction of the cylinder head, any flaws in the casting can be exposed, causing cracks in the cylinder head. A pressure test can check if these cracks are leaking.

A cylinder head can crack internally, so even if no cracks are visible on the cylinder head, it is always worth pressure testing to confirm that the cylinder head is OK to re-fit.

Why Skim A Cylinder Head?

When a cylinder head is removed from the engine block due to gasket failure, overheating etc., it is essential that you check the cylinder head and block to see if they are flat. Generally you'll find that the engine block is fine due to the size of it and usually being made of steel, but the head may show signs of warpage or rot. The way most manufacturers recommend checking the flatness is with a long steel rule or straight edge. Check across the length, across the width of the head in various places, and also diagonally from corner to corner.

Skimming the cylinder head creates a flat surface for the cylinder head to fit perfectly on the cylinder block. It is also advisable to have the cylinder block checked as well, especially if it is an aluminium block. If the cylinder block is warped then the block will need to be skimmed.

It is also a good idea to check the waterways on the face of the head for any signs of rot. It'll look like grey rusting, and if it gets too bad it can fill your cylinders with coolant.

Contact us today for more information on our services!