Now the internet jockey engine builder says it is irrelevant

Castings can be partially forged btw

 

We pushed the stock pistons to 680whp before the rod bolts let loose. I would highly recommend upgrading the rod bolts if you stick with the stock pistons and rods.

Michael

 

First of all, I wasn't even talking to you. At all. But since you made some asinine comment, I'll feel free to address it since this is a relatively "open" forum.

Learn how to read. I clearly stated that this info IS relevant to what the OP is trying to grasp. You look like you're arguing with yourself here.

Forging and casting are two mutually exclusive processes. Some casting processes approach the strength of forgings, and there are multiple different processes for forging. I've never heard of a forged casting or vice versa.

Michael what are your opinions on the stock piston and rod design? Just looking at the rods, they seem of a slightly more robust design than the Evo 4G63 and 4G64. Can't tell on the pistons, but the top ring lands/crowns seem shorter/thinner than those of a 4G63. I do know the top ring end gap is around 8 thou which is really, really tight. I've built several turbo engines with 22-24 thou up top with similar bores, so 8 thou just seems crazy. But so long as combustion chamber temps are kept in check, that gap will never causes any issues. I suppose the 4B11 runs cooler internally since it's an aluminum block engine...

 

please read
pistons on page 20
http://www.tomeipowered-usa.com/usa/...1_report_e.pdf

 

We've all read that before... your link is broken anyway:

http://www.tomeipowered-usa.com/usa/...1_report_e.pdf

But thanks... the photos included there are even more evidence that they're cast.

That grid pattern on the bottom of the piston is a dead giveaway that it's a cast piston. That whole center channel on the underside of the piston would have to be machined on a forged piston, yet the roughness of it implies it is cast. You cannot have fine-grain detail like that forged into a piece. You, however, can have them in a casting. Forged pistons come out as a slug which is roughly the size of the finished piston, and are machined down from there. You can notice the same on forged crankshafts and rods. They're very rounded and almost amorphous compared to cast pieces, and you can always note the large parting line from the forging. Parts of these pistons look that way, but the underside looks like a casting.

I honestly cannot say for certain without holding one in my hand or having some really good photos. Everything I've seen of the stock pistons and that I've read from tuners other than Tomei makes me think they're just a quality casting like every Mitsubishi piston in the past. They almost look identical to the Evo VIII-IX ones except they are full floating and the dimensions differ a bit.

 

What drove you to go the nitrous route instead of a larger turbo or something similar? Just trying to change it up a bit? I don't see many evo guys running N2O that's all.