Didnt post anything here to offened anyone just posting my opinion on this subject and nothing else! I feel that when I build a street engine for myself or a customer that it should last as long as a factory engine and we all know that these rods will shorten the service life of the engine. During the period that I have been dealing with engines all engines I have known of a few guys that run aluminum rods in their street cars but only very limited miles per year. And they were all manuals. I know the allison trans likes to aid the truck in stopping by down shifting and this is where I feel that the aluminum rods are the weakest. The rod bolt where it attaches to the rod will fail the aluminum isnt strong enough to hold the bolts in the threads. Thats the only reason that they wouldnt work I feel. If you had a manual trans and didnt let the engine slow the truck It word work just like any other rod.
Well, one saving grace is that our engines don't have much compression braking, hence less negative load on the rods.
My gut feeling is that if alum rods were a viable replacement for steel, you'd have seen them by now from an OEM. A modern engine is mostly aluminum, and some even have titanium rods.
For a race-only app, or a weekend warrior, they might be a good choice. But for the majority of us who use their trucks as trucks, steel is known and well tested. It would really suck to find out they get shorter or oblong over time, which is what aluminum does under impact loading. There is also the concern with temp. 7075 is a very high strength alum, it's even used for armor plate on the M113, and many aircraft frames. But at 300°F it loses roughly 1/2 it's strength if my reading is correct. It's why the SR71 had to go with a titanium airframe. Not because the alum melted, but because it lost too much strength at relatively low temps.
Who knows? I might try a set. But to be honest, if steel pistons are coming, I'll probably wait until then.
