Yes, forged piston won't give you anything if they are at the same compression level as stock... However, a forged "high compression" piston will make the squish area more dense and will generate significantly more power if the rest of the setup is dialed in and tuned properly... it's like the whole "anti-Gude" approach to a solid n/a setup... you can either mill the head, ie Gude, or you can go into the block and change pistons to raise the MEP.... we can go up to around 12 to 12.5:1 w/ the right tuning... and that will equal a "significant" power increase....Pimpstecy said:actually no if he would have said Forged Pistons... i woulda said ok.. but "PERFORMANCE" pistons... Just cus u have Forged pistons wont give you 10hp... its just gonna make yur engine stronguer and more durable... how can a Piston increase Performance? Catch my drift??
Wow Pimp, I thought you were more knowledgeable than this... First of all, compression is a function of several factors, on of which is volume... So, why do you think when you see "low compression" pistons they are usually dished or concaved? b/c they allow more volume in the squish zone and thus, less compression is induced given the same rate of flow (ie cam timing, etc) and stroke length... A "high compression" piston built for performance usually takes two avenues to increase compression: they are usually dome shaped and/or they utilize different wrist pin placements to get the piston further up the cylinder... Dude, it's basic geometry... if you have a cylinder w/ a given volume and you increase or reduce the surface area of one of the ends of the cylinder, the volume changes... so if you have a given stroke length you get a different volume as you shove that one end up into the other end... Please tell me you don't really think that higher compression pistons are called that b/c they can "take higher compression" :shock:Pimpstecy said:oh my god dude... yur Dumb.. (Edit: Im over-reacting)
"High-Compression" Pistons dont ADD compression/preformance/hp...
its High Compression Pistons meaning it can TAKE a higher compression. (i.e. Turbo or any other forced induction system.)
now shaving a bit off yur Head would highten the Compression... but I dont recommend it.
ok... unfortunately im already strapped for cash, so as it is i have to rebuild this beast one piece at a time lol, paychecks every 2 weeks instead of every week sux ass. anways, my point being that i cant afford to get a b20 block, not to mention i cant afford to pay to have sleeves put in. also, while im talkin bout sleeves, i read something in someones post last night that the b21a1 blocks are sleeved already from the factory. i just tore mine apart today and i can definately say theres no sleeves there. just a normal block. ive seen the inside of a 1.5L crx motor and i can definately say those are sleeved stock. so mine looks nothing like that. anyway why would i want to sleeve it, wouldnt it make the bore a lot smaller? i may be way out of the loop but it just doesnt add up to me. so now with the understanding that i want to just use my existing stock b21 head and block, what pistons should i use? OEM oversized, or aftermarket, or forged? also keep in mind in addition to eventually later on turbo'ing it, at the time of rebuild i am going to try to get my hands on some stage 2 or 3 cams if such a thing is made for the b21. i hope to god i can find some.To run forged pistons in a B21 it must be sleeved.
You are better off buying a b20a5 block and putting forged bits in that.
The stock honda pistons and rods are good for at least 230-250whp with good to excellant tuning.