Cylinder Head Reconditioning and Modification

The cylinder head will always be the key component of a performance enhancement package on any normally aspirated engine. The cylinder head has always been a reliable source of power that all successful race teams and manufacturers have utilised to stay in front of the competition.

Thanks to advancements in the industry, this technology is available to the man in the street at a competitive price and can be tailored to suit any specific need. Be it that you are looking for out and out horsepower or merely for improved fuel consumption and reliability, G&C has a cylinder head solution for all your Petrol or Diesel vehicles.

Ever wondered what it looks like when a Cylinder head gets skimmed. Have a look.

Posted by Goch & Cooper Auto Services on Wednesday, 18 July 2018

Inspection and Stripping

G&C are used extensively by leading agents for all their engineering needs.  This is a typical example of how we receive a head. Very rich fuelling causes such carbon build-up and in some cases lack of coolant in the cooling system also causes deterioration as the water channels of the cylinder head.

No job is too difficult for G&C and we have yet to turn someone away due to cracked heads, drop seats or guides or even bent valves which have caused combustion chamber damage.

Pressure Testing

When we receive a cylinder head, first of all a pressure test will be done. This is of vital importance as a defective head will not work well, no matter how well it is ported, polished, gas flowed or cc’ed.   We strip the head completely before we pressure test.  Each cylinder is sealed and pressure tested for any types of cracks, leaks or corrosion.

All ports, water channels and oil channels are also tested in the same way as well.

Cylinder Head Cleaning

Once we have determined whether the head is good, we acid-dip the entire cylinder head to ensure that all carbon, rust and sludge is removed from the cylinder head.The head is then sand-blasted and inspected further for any hairline cracks or imperfections.  If needed, we then repair any imperfections by the use of high impact alloy welding and then work down the repaired area to its original specifications.

It is essential that the modifications are carried out on a head that is as close to factory spec as possible.

Valve Seating

If we are happy with the performance of the cylinder head, we then proceed to the Serdi valve angle cutting machine.  Here we are able to accurately match the valve seat area after the valve guides are fitted. Various angles and seat thickness are available to optimize your valve seating for a better combustion chamber seal. Another flow bench test is then done to furthermore improve breathing.

With Serdi technology we are able to match valve angle to seat angle with the utmost precision.  This class-leading technology is at your fingertips during different stages of your cylinder head modification.

And back to the VR6 Cylinder head. A close up of Valve Seat Machining. Special angles to improve flow. The exhaust seat is critical as it transfers heat from combustion to the cooling system. Incorrect seat choice will cause premature damage. The inlet just as important. Perfection at its best.#GCENGINEERING

Posted by Goch & Cooper Auto Services on Wednesday, 5 September 2018

Porting and Polishing

Porting is done best on a stock cylinder head, as heads that have been worked out elsewhere, might not yield the desired results as that of one where work has been carried out on a standard head.  Bigger isn’t always better and with our extensive experience in cylinder porting, we can increase airspeed by up to 95%CFM (for those who do not understand this type of terminology, a standard head flows ± 80% efficient on the flow bench, so an increase in flow of up to 95% from that could be realised – we hope that this clarifies the process for those who are not in the know.)  This is what a head looks like after it has been ported.