I was working on a high effort X3 engine the other day and thought...what if SXS engines were cast iron instead of aluminum?
I know I know…it’s way heavier and it will rust. That’s dumb.
But is it though?
What is a leading cause of death of SXS engines? Heat. Aluminum moves A LOT at high temperatures. Bearing journal dimensions run astray. Round cylinders turn egg shaped. Head bolts fight for their life. Cast iron is more dimensionally stable at high temperatures.
Cast iron is cheaper than aluminum. Cast iron is better at dampening vibration than aluminum.
At the extreme end of the performance spectrum we break aluminum blocks, yank head studs out of them, or they flex to the extent of causing engine failure; so we extensively modify them with thick sleeves, thick billet girdles, and in some cases machine entire engine blocks from a billet for added strength and stability.
What if they were just iron?
Yes that would add weight, and we don’t like that, but now that larger model SXSs are well over 2,000lbs maybe it isn’t that big of a deal?
Aluminum dissipates heat more quickly, but cooling systems must already be designed to keep up with an engine covered in mud.
You know part of what made engines like the 2JZ so legendary? It was a big ole hunk of heavy iron that could withstand an enormous amount of power, and people made an enormous amount of power with them.
So maybe it isn’t a good idea. But maybe, just maybe, if an OEM gave us a tank of a cast iron semi-closed deck block capable of dependably harnessing new levels of horsepower, it too would become a thing of legend.
And we could all save a couple of bucks.
-Doug Butterfield
