Thank's Volkdent, that's what I call big answer
To be honest, I wasn't asking why intercooler increase engine life, because I have different opinion about that, and before I say it, I waited for You to say yours
I believe that;
intercooler serves as a charger (when we make things as simple as possible). It's main rule is to cool air, so we can put more of it into cilinder and get more power and that is by making engine more efficient. OK, so it's true that colder mixture cools heads better, but the volume of mixture that enters the cilinder is bigger, so combustion temperature is higher (which make our engine more efficient). With intercooler, we always get bigger temperature oscilation, because burned mixture is hotter, and prepared mixture is colder. All we do, is making more temp. oscilations which is (in theory at least) not good for engine life. Remember the reason why Porsche water cooled their engines? Because of the uneven head temperatures and heat oscilations. 959 had hybrid cooling. Cilinders are cooled with air, and heads are water cooled.
We all agree that intercooler increases HP. No argue about that. And that is by making engine more efficient. Modern turbo diesels over here in Europe (VW lupo 3L 1.2 TDI) have efficiency of 43 percent. Good gasoline engines in Europe have 30 percent efficinecy. Diesels efficiency comes with turbos, intercoolers, big compression ratio AND bigger temperature to cope with. They are unbelievely economic and they make big torque. That's the reason why we haven't had a diesel made completely of aluminum until recent (heads are rarely aluminum, but crankcase is ollmoust allways cast iron). Gasolines are often made of aluminum. Toyota made first diesel aluminum engine, 1.4 D4D. Why? Because cast iron is far stronger and it can whitstand that kind of heat which was raised to get more efficinecy. The point is, engineers raised heat to make more efficient engine, like we do with intercoolers. Toyota's engineers reduced compression ratio so aluminum can be used, and less weight achieved.
Intercooler = more efficiency = more heat = decreased life
I agree that intercooler may on some engines increase life, but decreases in most applications. There's too many things that has to be cosidered, so we cannot say that in general intercooler increases life. Actually, I would say the opposite is true, but I don't want to "generalize" things.
Cheers!
