today I ask the tech world a simple question,
what do I need to do to my h22a1 engine to make it push 400whp + on a dyno?
drop in mahle golds with arp head stud kit, that's all I can think of, if anything else please feel free to drop a comment

 

Mahle golds are met with very, very mixed success. 80% of what I've seen ends up in an expensive disaster. Full sleeve + proper pistons is the only way to be sure it's reliable.

Nippon Racing makes cast turbo/nitrous pistons made from a more suitable alloy for that sort of thing. Compatible with stock sleeves. Rated for 350 but have been pushed much higher with a lot of success. They only come in Type-S spec, 11:1, so hope you have a good manifold and knock resistant fuel available if you go that route.

 

I ran a cast piston in NA h22 that wasnt OEM, it swelled up and essentially melted to the cylinder walls. It was a high compression motor and ripped.... for a minute. I would sleeve a H22 if I were going that route again.

 

Cast shouldn't swell noticeably under normal circumstances. You may have been running it lean and gotten too much heat into it.

I too recommend the sleeving route though. It's the only way to make it properly reliable for high horsepower.

 

Whether it’s a B, D, K, H, F series etc. forged pistons, forged connecting rods, and sleeves are recommended. People have achieved 400whp with less than pistons, rods, and sleeves, but it’s highly recommended.