Whether you drive a modern or older car, it is possible to improve engine power and efficiency by fitting selected performance products which simply bolt on to the engine externals. High flow air filters allow the engine to breathe better which, coupled with adjustments to the carburation or injection, will provide an improvement in power and response. Most factory fitted ignition leads are carbon cored and these will deteriorate with age. Fitting a high specification lead set will restore engine performance (especially under heavy engine load conditions), and will also improve cold start operation. While on the subject of ignition, if your car is an older model, fitting an electronic ignition kit will ensure peak performance for all conditions - and there are no points to worry about. Engine driven cooling fans are renown for causing all sorts of problems. In the summer, in traffic, they allow the engine to overheat - in the winter they prevent the engine warming up properly - and driving those fan blades around absorbs a lot of useful engine power! The answer, of course, is to fit a thermo-statically controlled electric cooling fan.
The value of any improvement or performance upgrade will be determined by the 'health' or otherwise of the engine in question. The areas of improvement mentioned thus far are fairly modest but to venture much further along the road to high performance will be doomed to failure if your engine is not in a sound condition. Some bolt-on products such as carburettor conversions or engine management (chip) upgrades will increase the stress placed on an engine and can exacerbate any existing wear problems, so it is always a good idea to have the engine fully checked over and serviced beforehand. At the very least make sure the engine is treated to an oil and filter change using synthetic or premium quality oil.

Last, and probably one of the most popular bolt-on performance enhancing items to be purchased, is the exhaust system. Many original equipment exhausts are restrictive in their design and the full potential of any increase in engine power will not be achieved until the exhaust is replaced with a suitable free flow system. A very comprehensive range of manifolds and systems are available for most cars including the increasingly popular stainless steel types.

So let us now move on to the more serious aspect of engine modification. The next logical step is to modify the top end where, in most cases, substantial power gains can be achieved. Choosing the correct stage of cylinder head and matching this with the right camshaft is very important, and at Burtons we are always on hand to advise our customers on the best combination for their specific usage. Most modern engines are overhead cam (OHC) design and removing the head and cam can be carried out with the engine 'in-situ'. For older overhead valve (OHV) pushrod engines, a cam change will almost certainly require the engine to be removed from the chassis and at least a partial strip down of the bottom end.

Finally, any attention or modification to the bottom end will require a complete engine strip down. If the cylinders are to be rebored then an increase in engine capacity is always worth considering. Whilst on this subject, it should be recognised that one of the easiest routes to more power is to fit a larger capacity engine. Many cars have various engine options for any given model so moving up from a 1300cc to a 1600cc engine or a 1600cc to a 2 litre should give a very noticeable increase in performance.