Ask any engine reconditioner what the most important engine issue is and they'll mention cylinder heads.
This is because improving an engine's output has a lot to do with ensuring that the cylinder heads operate at the highest level of performance. When engine components like cylinder heads are in tip-top shape, things quite literally run a whole lot smoother.
An important phase of the engine reconditioning process is to closely examine the engine cylinder guides and seals. When the seals become worn out, you'll notice an increase in oil consumption. This is largely due to oil leakage, and can end up costing you much more in replacement oil than you'd otherwise have to buy. Worn guides are even worse, as this can lead to them failing to efficiently control valve movement.
Cylinder heads in bad shape can be detrimental to overall performance. When the combustion chamber isn't sealed, horsepower is lost to the exhaust system. As part of the reconditioning process, valve seals can be cut and positioned depending on the purpose of the engine. The angles of the valves will impact the output horsepower, so it makes sense – if you're looking to get the most out of your engine – to use an expert engine cylinder refurbisher.
When it comes to engines, it really is better to recondition than to replace. Too often under-performing engines are simply scrapped and replaced in the name of convenience. It might take a lot of work to recondition an engine to manufacturer specification, but this will work out a lot cheaper than buying a new engine. The truth is that engines weren't designed to break and be replaced, so companies can save money and resources by choosing to recondition instead.
The engine reconditioning process can involve – depending on the specific job – milling, re-engineering, and/or replacement of parts. While there are engine refurbishing processes that can be done at home using specialist kits, this might not guarantee getting the best performance out of the engine, or worse – this might end up damaging the cylinder heads if not done properly. For this reason, if you value your engine and would prefer not to risk damaging it beyond repair, rather let expert automotive engineers handle your engine reconditioning.