Hi guys ive googled the **** out of this and cant find anyone who has actually ran these pistons on frm.
Are they ok to use ?

Also i keep hearing 11.5+ cr is dangerous on frm ! Any truth in that ?

 

got a link to nippon racing pistons? last i knew that was an obx brand for their wheels.

 

Theres lots on ebay dude. On my galaxy so no link !
There advertised as teflon coated and anodised top and i have seen there quality because i stupidly bought a set before i realised h22's are frm....yes i should have researched but ive owned bseries before so assumed the same steel liners.

There a cast piston rather than forged which is why i got them. I did come across stuff on forged pistons killing frm .

 

From what I recall, they advertise as being an oem replacement, but are not actual "oem". Most people stick with oem or Mahle in the FRM sleeves, or re-sleeve and do forged pistons.

In regards to FRM, the compression ratio makes no difference at all, it is all in compatability of the piston material to the sleeve, and piston-wall clearances when assembling the engine. There are a few guys out there making 500+ WHP on FRM sleeves with the Mahle pistons, but they were assembled very well, exaclty to the given clearances.

If you want to rebuild with oem pistons, I wouldn't trust the Nippon pistons personally, just find some oem type-S pistons. Probably the easiest to find would be a set of overbore sized, which would require a machine shop well versed in honing FRM liners, as it is much different than other engines. I have a set actually, but decided to not mess with my block, and use more standard sized pistons and deal with a little less compression.

 

I plan on machining the block anyways there are some small scrathes on the bores.
Tolerances will be blueprinted close to the tightest honda recommend.
Lots of people have made good results in power and reliability on steel sleeved blocks so im not worried about quality its just will they eat the liners even when toleranced correct and if so how long do i have !ha

My nippons are .25 over btw

 

oh i thought you were referring to some other brand, didn't realize you meant NPR (nippon piston ring co.).

I cannot speak for the h22a, but I know for every other Honda engine they work great. NPR is also a HUGE oem supplier (and afaik have been a Honda supplier)but I cannot verify that they supplied the original pistons for the h22/h23.

 

Yeah they supply headgaskets and the like.
I'll give it a shot and let you guys know how i got on