My bad on the mix up. Actually yeah, you're right, the block is iron, the pistons are aluminum and have one nitrided and one chromed compression ring on each piston. The crankshaft and rods are steel. Come to think of it, if they are steel that probably means they are forged...right? I don't know much about forged stuff other than my golf clubs. Well one thing I do know, the main journals on the Supra are frickin' huge and there are seven of them so flex doesn't come into play at just about any amount of power.

 

The RB26 has an iron block also.

 

Thank you, I'm not sure what gave me the idea that the RB26 was aluminum. Is the SR20 an aluminum block?

 

Yeah the SR20 is aluminum. But its predecessor CA18DET that was in the 180sx/silvia had an iron block and was considered the RB26's little brother.