Why Replace your VW Engine?
Many people like the idea of getting more modern performance, economy, or power out of their old VW’s. The power and performance of any VW horizontally opposed engine can easily be vastly improved above standard with the modern tuning technology available. However, rebuilding a standard VW engine to a high standard is very expensive. If you’re after better power or performance too, then the cost can easily be more than three times the cost of an exchange reconditioned engine, just to get the sort of power considered ‘normal’ in a modern vehicle. Also, particularly the watercooled T25 / Vanagon models tend to have a habit of outliving their engines, which are plagued with ‘head stud problems. If you want to retain the VW engine’s reliability, or match the drivability of a modern engine, or increase its economy, you would have to find a highly skilled engine builder, and will probably need an aftermarket engine management system too, all costing more. Whilst most people like the idea of retaining their VW air cooled engine, to swap it for something more modern can be much simpler, quicker, and more cost effective.
If you are looking for an engine conversion for your VW, you are probably looking for either the smoothness, power increase, and / or economy of a modern car, or for out and out horsepower. You are probably also concerned about having a high quality installation, which ‘looks right’ once completed. VW owners generally seem to take a lot more pride in the installation quality and attention to detail in the modifications that they do than modifiers of many other marques do. If you want a conversion which will look the part when it is finished, then this limits you to either other horizontally opposed engines, or maybe the ‘tilted’ in line four engines, like the diesels used in Type 25’s (Vanagon’s), if you’re converting a bus, Karmann Ghia or Type 3, with their longer engine bays. If you’re converting a Beetle and want to retain the original rear bodywork shape, then your only choices are another compact flat four engine or maybe a Wankel rotary engine.