hey ive beenreading a lot of good things bout NPR pistons...

questions i had:

dsm tuners were saying how NPRs are OEM pistons without the mitsubishi markup in price.. is that true? did they also make OEM pistons for honda?

anyone on here use them? any good or bad stories to tell? (and what hp numbers/boost were they stressed under)


my h22a1 needs new rings/pistons. i wanted to put a set of upped compression Type S replicas in...

the price isnt bad, people say theyre cheap, but the last time i called honda regarding pistons, they were 50$ each..and OEM is always sort of expensive so idk

many people ive read have done numerous rebuilds with them and loved them. i did read a story about a guy who had one crack in his gsr(i believe) after a couple thousand miles..idk if the guy was boostin tho..

also, are they tougher than OEM quality? i dont know much about the hardening/manfacturing process of pistons, but someone said that they were T6 heat treated??

not looking for an expensive set of pistons to go into the engine, just a reliable set that can get macked on occasionally.
anyone have any helpful information? thanks.

 

No. NPR is their own company, they do not make Mitsu pistons, nor honda. They make replicas in cast, so perhaps that's where the interpretation gets lost, but hehe.. no. not true.

This is a company set that if you so feel inclined might have to be experienced by yourself. I'm afraid many of us can't give you an accurate frame of reference.

 

/forums/cylinder-head-short-block/230673-nippon-pistons

https://honda-tech.com/forums/honda-prelude-4/nippon-pistons-rings-r-they-any-good-3015032/


heres two out a few threads i found regarding them. i wonder if they are any good..they seem to be a good piston for an average allmotor setup and many claim they are slightly better than stock so im not too sure... id hate to gamble on something like this but im not really trying to blow any more money on this car than i have to lol... bump to see about any new experiences with these.

 

if you buy please post overall summary of pistons will b looking for new ones for spring

 

Used them in my LSV, (used the PR3 pistons) with rings, no issues after 45k miles, will be sprayed on and skunk2 tuner 3s here shortly. As well as used them in a mild GSR motor rings as well no issues. I stand by them.

 

Ive used them in a gsr rebuild with no problems

 

cool beans..im kinda leaning towards choosing them over some of the higher priced competitors...i've only read one person that said he had a bad bad experience with them saying "he cracked a piston in his gsr after after a few k miles" but who knows what could have caused that.

anybody else? really curious about any new information on these.

 

i might run them as well in a b20v 11:5 82mm on spray

 

Aftermarket "replacement" pistons. Tougher then OEM quality? IMO yes... strictly based on the fact that you wont have issues with the ring lands on the aftermarket pistons. They are still cast pistons however, typically of a much more durable quality then OEM, but I dont know if anyone is fully certain of what OEM pistons are made out of or what heat treating process is done to them. NPR's like RS machines and YCP are all 336 cast (AC8A in the japanese grading system) which means they are a higher silicon content aluminum cast piston, not toughened by the forging process. The thing that makes them tougher then regular cast would be the T6 heat treating process they under go, which makes their tensile strength much higher, closer to that of 4032 aluminum alloy, which is what most low expansion forged pistons are made out of.

Let me know if you need a set, i have YCP's in 84.5 for a B20 im trying to unload.

 

wow great post. thanks for the info.