Engines for sale often have defects of their own and therefore a thorough inspection needs to be undertaken before any money passes hands. The reason we say this is because if you are looking to rebuild an engine, then why waste yourself or your engine rebuilders time as well as money. It is also essential that when gathering information about the engine you are interested in that you find out how it was stored. Reason being that engine blocks which have been stored outside fall prey to harsh weather conditions which can cause cracks and pitting.
When viewing the variety of engines for sale, it is imperative to find out if the engine block was previously machined. If it has, it is essential that you or the engine rebuilder inspect not only the cylinder bores, but the crankshaft main caps. If the person of company is telling you that the engine has not been machined, an easy tell is on the crankshaft main caps as they will often have a cross-hatch pattern from being honed. Non-machined engines will not have the pattern as they will have only have been bored in the factory. It is generally the norm that engines that have their original main caps will save you and the engine rebuilder both hundreds if not thousands of rands, but time as well as the cost and effort required for align boring and honing is high.
It has also been said that engine blocks are best inspected when clean as this makes any defects that the engine may have visible. So to sum it all up, the inspection of any engine that you are considering purchasing is imperative in order to save you both lots of time and money. Storage facilities, cylinder bores, and crankshaft main caps need to be inspected thoroughly on any of the many engines for sale.
The following video is a 3D animation on how a basic combustion engine works.