Hi, I have been hearing a lot that nothing is better than a stock engine as far as reliability is concerned. If I were to buy a used car and do a swap should I buy a used engine that hasn't been touched or something that someone already did a little work on. What mods decrease reliability.

 

mods that are mainly bolt on do not harm the engine unless its a SC, Turbo... like exhaust and intake and the like can do minimal damage to the motor. what damages a motor is wear caused by hard driving and no maintainence. reliability comes from knowing what wear is caused by your driving and counteracting it with the appropriate TLC and parts replacement schedule. I dont mean plugs and oil changes either, while that helps. If you beat a car, it can still last a long time if you have watched your levels, maintained good timing belt tension, watched the T belt tension, kept the timing under 18BTDC and kept a decent record of the maint you have done. as far as increased power, keep in mind anything will work well for a while but know why and how things wear as you increase certain parameters and you can extend the life of any motor.

 

Choosing the right Air filter system is very key. Dirt entering the engine acts like sandpaper scuffing internals. So, if you plan on modifying your intake, make sure you don't develop 1) Air leaks and 2) Buy a good quality filter.

Regards,

Oz