Aluminum has its strong points, for sure, You pointed out some of them, and in certain applications, I'm sure you are right, particularly the repairability issue, where cast iron is just a living nightmare to deal with.
Chrysler gave up on the aluminum /6 production when they had foundry problems too frequent and too numerous to deal with; it wasn't that the motors didn't perform well... it was just production issues that killed it. They managed to send 60,000 copies out the door, before changing over,completely, to cast iron though, so, they're out there, somewhere, if that's the direction you want or need to go.
The parameters involved in putting together a high-boost /6 are more about rigidity, resistance to flex, and general strength of the block and head, though, and that's where the tensile strength of the iron castings seem to shine. They are just super-strong where they need to be. No other engine that I know of, has the capability to absorb high boost levels without incurring trauma to the basic infrastructure, as the /6. Its basic design features (thick deck, 84-pound cylinder head, forged, crank, big bearings and small bores seem to beg, "TURBO ME!!!! YOU'LL LIKE IT!!!"
The only thing they missed on, was the inherent design limitation of 4 head bolts instead of 5. That's a shame, but ARP makes some stronger studs (220,000-pound-per-square inch material, instead of the standard 180,000-psi) that may take care of that problem. They also have some REAL exxpensive 260,000-pound material studs, if that doesn't fix the "head-lifting" problem, down the road.
We'll see....
Chrysler gave up on the aluminum /6 production when they had foundry problems too frequent and too numerous to deal with; it wasn't that the motors didn't perform well... it was just production issues that killed it. They managed to send 60,000 copies out the door, before changing over,completely, to cast iron though, so, they're out there, somewhere, if that's the direction you want or need to go.
The parameters involved in putting together a high-boost /6 are more about rigidity, resistance to flex, and general strength of the block and head, though, and that's where the tensile strength of the iron castings seem to shine. They are just super-strong where they need to be. No other engine that I know of, has the capability to absorb high boost levels without incurring trauma to the basic infrastructure, as the /6. Its basic design features (thick deck, 84-pound cylinder head, forged, crank, big bearings and small bores seem to beg, "TURBO ME!!!! YOU'LL LIKE IT!!!"
The only thing they missed on, was the inherent design limitation of 4 head bolts instead of 5. That's a shame, but ARP makes some stronger studs (220,000-pound-per-square inch material, instead of the standard 180,000-psi) that may take care of that problem. They also have some REAL exxpensive 260,000-pound material studs, if that doesn't fix the "head-lifting" problem, down the road.
We'll see....
