You should set the maximum wear to some obscenely high value with a line like:
setMaxWear(kmToMaxWear(990000000000000000000000000000000.0));
this line should go to the constructor of the block under the
super(id);
line also the noreshade version of the exe fix under LINK has a setting for this named WearMultEngine which scales the damage to engine parts (though all the engines are affected by this)