OUR Project Citi Golf has had all. Burn more important than volume the preventative work, as well as a major service, completed by Steve's Auto Clinic (SAC). Now as promised, it's time to get into piling on the horse- power.

The first stage of this process focuses on the cylinder head and camshaft - the most important area for the serious tuner to consider. And good news is that SAC are the ideal guys for this job, being one of the only independent workshop groups to offer their own in-house full engineering facility.

A cylinder head will always be the key component of performance enhancement packages on any normally aspirated vehicle, and its design is crucial.

There is no way in which high horsepower can be obtained if the head won't flow efficiently and in turn burn the air/fuel mixture efficiently.

Airflow figures tell very little about how well a head has been modified. There is no point in forcing high volumes of mixture into an engine unless you can burn it at the right time, and if you try too hard to get high flow figures, you could easily end up with a combustion chamber that won't burn effectively.

Most people also seem to think that a cylinder head conversion means turning a perfectly running vehicle into a racing car or a unreliable lumpy idling, impossible-to drive monster.

Unfortunately some tuners do end up producing this sort of result, but SAC have a far more professional approach.

Their motto has always been "Achieve reliable power". As the cylinder head is a proven source of reliable power utilised by all successful race teams and manufacturers to stay in front of the competition, SAC has adapted this technology for the man in the street at a competitive price and tailored to suit any driving need.

Whether you are looking for out-and-out horsepower or merely for improved fuel consumption and reliability, SAC stock a host of replacement new and reconditioned cylinder heads that are fully gas-flowed or in standard trim.

Alternatively, they can remove your car's existing cylinder head and repair it, recondition it and gas-flow it at any one of their branches country wide.

This is what we opted for on our Citi Golf and we now have a 1,4 litre powerplant that breathes better than most 1,8 litre engines.

Backing up this service, SAC also offer a full range of other engineering facilities such as pressure-testing of heads, repairing of heads, and sourcing and making the various internal parts in the head. They even cut cams and manufacture valves.

Catch us next week Saturday in CitiMotoring as we fit a proper performance branch and exhaust system to the Golf.