type-s pistons std vs .25os

[DrLove'sKuDang]

i heard they both fit the stock bore of the h22 block, if thats true, then whats the difference with the .25os? does it actually serve a purpose? if not, then ill just get the standard size cause inlinefour has the piston/ring set for $360. if i can get the os pistons, then jhp has the set for $380.

so whats the diff, and would there be a difference in gains?


btw, some guy on ht was supposedly selling a stock shortblock w/os types's... just wondering how he put 25over pistsons in the stock sleeves, or if he was full of it.

[h22sparkle]

You can get the standard pistons thats if you didnt sleeve up the block. NO there arent any gains from the stock pistons but if you put the type s pistons in there perhaps with a thinner headgasket it should help. Reason being that your soon to be type s pistons love bigger cams than stock and your runnin the skunk2 stage 2's right. Higher compression pistons love meaty cams as long as they arent to big and tuned right.but yourll be goin from 10:6:1 to 11:1 with the thinner headgasket 11:5:1 with those pistons tuned = vtec fury

[clarksterdotcom]

i heard they both fit the stock bore of the h22 block, if thats true, then whats the difference with the .25os? does it actually serve a purpose? if not, then ill just get the standard size cause inlinefour has the piston/ring set for $360. if i can get the os pistons, then jhp has the set for $380.

so whats the diff, and would there be a difference in gains?


btw, some guy on ht was supposedly selling a stock shortblock w/os types's... just wondering how he put 25over pistsons in the stock sleeves, or if he was full of it.

yes they do fit the stock block, both of them. they OS pistons fall within the proper specs for a service hone on the h22 block (accrd. to the helms and a couple mechanics) youll want to hone the block when you get type s pistons regardless to give the pistons a "fresh" surface to "seat to."

youll need a hone because i have heard that the cylinder walls tend to "flare" making the top a bit wider than the base (this is just what i have been informed by a mechanic and have not seen them measure this in person)

JHP btw is a great price for those pistons.

gains are throughout your powerband. though i havent seen dynos after just a piston swap. they bump CR like h22sparkle said from 10.0/10.6 : 1 to 11.0:1 and this doesnt take into account what your other mods have done for CR.

i know i might seemed biased since im the one whos friend is trying to sell some type s pistons, but trust me...these are planned for my h22a as well.

i dont know how agressive the skank2 cams are but i know the type s cams w/type s pistons is a formidable combo on any h22

[clarksterdotcom]

i plan on using the type s pistons, flat faced valves, Rocket Motorsports custom or regrind cams (inc. head package), light head mill, and some serious engine management for my h22a, w/e i do though im shooting to get about 11.5-.6 CR for some good pulls on an all motor h22 (w/full interior 91 LX coupe)

[green5thgen]

i plan on using the type s pistons, flat faced valves, Rocket Motorsports custom or regrind cams (inc. head package), light head mill, and some serious engine management for my h22a, w/e i do though im shooting to get about 11.5-.6 CR for some good pulls on an all motor h22 (w/full interior 91 LX coupe)

Be prepaired to have 12.0:1 compression if you do this if not more. The pistons put you at 11.0:1, high compression valves(flat faced like you say) put you around 11.4:1 in an H22, and just milling the head .010 for a clean start will raise an H22 .27 more for a total of around 11.7:1. If you do any more to the head than .010 you'll be around 12.0:1 and that's pushing the limits of 93 gas if you have any decent cam. Just food for though, but an AEM stand alone would help out alot with the octane problem. Good Luck.

[DrLove'sKuDang]

actually i have crower 2's, but whatever. im gonna be getting a complete a4 block, but i need to put new rings in anyways, so i figured i would go type-s.


so lemme double check here, if i DONT sleeve, is there a power difference between standard and oversized pistons? will gettin the os pistons give it a tighter/better fit since i have to hone the block anyways? i dont wanna hone and then have standard pistons that have too much play.

[GrayCar]

You have to hone anyway with new pistons. The .25os pistons will require a bore also. The .25 overbore takes the sleeves out to the service limit. The os pistons are Honda parts for Honda motors, they don't want to sell you something that forces you to buy non-Honda parts.

Look at how much the overbore will increase displacement. How much torque are you going to gain for the cost of having your sleeves bored? Is it worth it?

As far as piston slap... honing isn't going to take that much off the sleeves to begin with.

[DrLove'sKuDang]

You have to hone anyway with new pistons. The .25os pistons will require a bore also. The .25 overbore takes the sleeves out to the service limit. The os pistons are Honda parts for Honda motors, they don't want to sell you something that forces you to buy non-Honda parts.

Look at how much the overbore will increase displacement. How much torque are you going to gain for the cost of having your sleeves bored? Is it worth it?

As far as piston slap... honing isn't going to take that much off the sleeves to begin with.

great, thanks alot. guess ill be sticking with the standards... dont have extra money to waste on boring.

clarksterdotcom: can ask your friend how much he'll let the type-s go for. i figured you would get to him sooner since i never see him online.
thanks.

[GrayCar]

great, thanks alot. guess ill be sticking with the standards... dont have extra money to waste on boring.

It's actually the same route I'll be taking with a motor I bought off an above poster. I won't say who, we'll see when it gets here.

[clarksterdotcom]

great, thanks alot. guess ill be sticking with the standards... dont have extra money to waste on boring.

clarksterdotcom: can ask your friend how much he'll let the type-s go for. i figured you would get to him sooner since i never see him online.
thanks.

ill see what i can do. im working a lot more and imtaking a shitload of summerclasses... will try though.

[h22sparkle]

also you better have your shit tuned right for 12:1 cr or else youll hearin ping,ping ping like marbles in a pot rattling around meaning its going lean better hope whoever is tuning your car knows how to tune.

[DrLove'sKuDang]

also you better have your shit tuned right for 12:1 cr or else youll hearin ping,ping ping like marbles in a pot rattling around meaning its going lean better hope whoever is tuning your car knows how to tune.

i wont be 12:1, the type-s' are 11:1... everything else is stock.

[bagoon316]

i know this is a lil off topic but 360 is overpriced...i jus called honda 2 days ago and they called me back cuz its special ordering...it was only 275 for all 4 type s pistons with rings. i then called another race shop that does all honda swaps cuz i thought that was way lowballed and asked them...they called me back cuz they had to call there japan dealer or some shit and they said 280 with rings...they also said to throw the stage 2 skunk 2 cams in with it cuz the jus the pistons wont do much...and the skunk 2 cams were only 100 more than the type 2 cams. jus a lil info for ya i hope it helps.