Cylinder heads and cylinder blocks

Deciding whether to fit a new cylinder head or cylinder block to your car can be difficult. They’re not cheap, and it might be that the original head or block can be repaired, at a cost.

Sometimes minor issues with heads and blocks can be repaired, but it is difficult to guarantee the longevity of the repair and how effective it will be. When there is any doubt, we advocate fitting a new cylinder head or block, which is why we manufacture these for both small and large horsepower cars. The cost of fitting a new head or block can be vastly more economic in the long run compared to trying to repair the original.

Original blocks and heads

Sometimes original blocks can be cleaned and repaired, however the descaling process alone can be a long and costly process - 80 years of deposits, anything up to 2 kg worth(!) can take many man hours. If this is not done thoroughly, you might not find out until it is too late. Only once the deposits are removed can one assess the state of the 80 year old casting beneath, and often discover the material is cracked or too fragile to repair. By the time you decide the block is not fit for repair you have already incurred substantial costs for cleaning and testing.

Original heads and blocks often suffer from cracks which are visible on the outside of the casting. However, there may be cracks deeper within the casting which can be harder to detect and which can be difficult if not impossible to repair. In order for any repair to be successful the structure of the part must be strong enough to withstand the repair process. If a repair is being contemplated we do not advocate any welding process, but recommend that a cold stitching process is employed.

If you’re considering repairing your existing head or block, or investing in a new one, get in touch with us to discuss your options. Call us on +44 (0) 1367 810 438 or email us, and don’t forget we give a discount of 15% on all Fiennes manufactured parts fitted by us in our workshop.

Bentley cylinder head manufactured in our workshops

Silver Ghost cylinder block manufactured in our workshops