The maximum horsepower figures of most car engines have been high for many decades.How long would an engine last on the dyno when making max HP ? How would this expected life drop when aftermarket performance mods are added? Would large old V8 motors like stock chev 350 be better in this respect? When I would see Vintage petrol engines used in generator sets the max cont KW output of the generater was more than half of the BHP of the engine . These old gensets were setup to make 50Hz running at a governed 3000rpm.The old engines that I have seen ,are Flathead ford V8.Coventry climax in line 4,Austin 36HP OHV inline 4.Would modern car engines have to be derated for such service?