Nippon NPR pistons.

[Hmong_1G]

I have searched with no true answer to my question but those mk3 owners like myself on a budget, anything cheap sounds good. My block has 170k and I'm thinking about just new rings, but if NPR's are this cheap I would go over bore. Problem is that being an ex-dsm owner and knowing for a fact that NPR pistons have weak ringlands... and is seemly a on going problem for 4g63T. So my questions is can they be constructed differently from Nippon for the 7mgte? Any insight on this would be greatly appreciated. I know that the machining work is just as important and critical as any other part on a vehicle. I'm looking into probe forged ones also, only if I can get this D series Jackson supercharger sold.



PS.... Im searching and found that any supra produced from 90-92 has larger intake and exhaust head ports. TRUE?

 

[rayall01]

A lot of the npr products you see on ebay, and elsewhere, are cheap chinese knockoffs. Stay away. I got my pistons, rings, and bearings, on ebay, but the manufacturer was Evergreen autoparts. Seen at least one other guy on here with that brand of parts, and never saw anything bad about them. They're working fine in my car at the moment. Only problem, I don't see that set on ebay anymore, so I don't know if they're available anymore.

 

[BrandonW]

i was checking out the npr pistions also to do a .020 over driftmotion has them on their site so they are not some knock off or cheaper version but i believe many on the forum here have use them, maybe they will say something

 

[Mr.PFloyd]

i use them. i had my car set up at 350whp and 18 psi of boost for 6 months, then winter storage. no signs of blow by and compression is even across the board.
I would use them again.

FYI, the Casting process of anything now a days isn't really different from manufacturer vs manufacturer.

 

[rayall01]

I'm just saying lately that I've seen posts concerning NPR knockoffs, and you should avoid ebay and other cheap sites. I didn't say NPR itself was a bad brand.

 

[bluezone]

i used a set of NPR's last year. no problems so far. they seem to be reinforced the same as factory pistons and were about 10 grams lighter than stock.

 

[Velocityfreak]

im not dissing NPR pistons or any of you guys that have them, but ive never heard of them, by the sounds of it, they are a major piston manufacturer and they make a good product. Personally I would go with the probe or JE slugs - they are proven, and way lighter than stock anyways, and if you are doing a build that is more important than skimping on cheap parts.

 

[Doward]

I have to say - with Probes so cheap, why not go forged?

 

[Hmong_1G]

Thanks guys... I really appreciate your fast response. Fact is that I'm not building a high HP machine. I love my supra and in stock form, already kicked good azz. 170k on factory HG with little to no blowby. Not bad huh??? Babied it when purchased from an old old lady. Owned it since 90k... 8.5 yrs. =)

 

[rtrdpenguin]

I used them in my engine and have no problems

 

[grimreaper]

I have to say - with Probes so cheap, why not go forged?

^ this

 

[7M-KDL]

is there a way to tell if they are knock offs or not? the reason i ask it bc i already have a set, came with my car, that are supposed to be .20 over. if they are the real ones and better than stock i might as well bore and use them right? btw im pulling the motor in about two weeks to do a semi rebuild...

 

[CyFi6]

They are just stock replacements. Im not sure about Chinese knockoff ebay pistons, im not sure where people are getting that information or what backing that has, or if the "knockoffs" are of any less quality to begin with. I ordered a set of 1mm oversize pistons/rings from Mizumo (they sell on ebay) and my pistons came from this "Evergreen" auto parts as well.

 

[7M-KDL]

They are just stock replacements. Im not sure about Chinese knockoff ebay pistons, im not sure where people are getting that information or what backing that has, or if the "knockoffs" are of any less quality to begin with. I ordered a set of 1mm oversize pistons/rings from Mizumo (they sell on ebay) and my pistons came from this "Evergreen" auto parts as well.

yeh i have a whole gasket kit in evergreen packaging and a set of npr pistons and rings, which i assume are from mizumo as that is the only place i have seen them, i need to measure the pistons to make sure of what size they are, i was told they were .20...



EDIT: I just went and looked at them and they have 050 stamped on them. is that .50 over or something different entirely?

EDIT2: checked the box they came in, says they are from Mizumo Auto.

 

[gixxer750]

I have to say - with Probes so cheap, why not go forged?

because a forged engine, more often than not will have mild piston slap and extra noise that may mess with the knock sensors. Generally a built engine will not last as long as a stock component engine.(of course, these NPR pistons aren't oem either).


In the 2jz world, I've had built and oem shortblocks now. In all honesty I would rather have a stock shortblock if it meets the requirements of my power goals.
the 7m-gte stock pistons are pretty strong. Possibly stronger than the rods.

 

[gofastgeorge]

A lot of the npr products you see on ebay, and elsewhere, are cheap chinese knockoffs. Stay away.

2nd that !
I have personally traced some NPR rings back to a chinese manufacture.
Also,
I never believe a seller who says that 'their' NPRs are not chinese,
when they have other chinese parts listed on their site.
And seeing that 95% of supra parts on eBay (chinaBay?) are chinese,
Then most likely the NPRs listed there are knock-offs.

 

[grimreaper]

because a forged engine, more often than not will have mild piston slap and extra noise that may mess with the knock sensors. Generally a built engine will not last as long as a stock component engine.(of course, these NPR pistons aren't oem either).

Come on, thats a bit of stretch! Youd have to get lucky to hit the frequency the knock sensors are looking for with piston slap. Not to mention if it doesnt go away once warmed up... somebody built it to loose.

A properly rebuilt motor should last just as long as stock, how does stronger parts = shorter life span?

 

[gaboonviper85]

Come on, thats a bit of stretch! Youd have to get lucky to hit the frequency the knock sensors are looking for with piston slap. Not to mention if it doesnt go away once warmed up... somebody built it to loose.

A properly rebuilt motor should last just as long as stock, how does stronger parts = shorter life span?

when referring to pistons it would be because there is much more heat expansion and contraction....more clearance for parts to move around on cold start which accelerates wear....good machinists can minimize this but there is a reason why very very few cars come with forged pistons if any....forged has more power potential and is a much stronger mfg process but it does indeed have its downside and generally that is lifespan.

 

[CyFi6]

yeh i have a whole gasket kit in evergreen packaging and a set of npr pistons and rings, which i assume are from mizumo as that is the only place i have seen them, i need to measure the pistons to make sure of what size they are, i was told they were .20...



EDIT: I just went and looked at them and they have 050 stamped on them. is that .50 over or something different entirely?

.50 mm = .020"


And about tracing the NPR rings back to Chinese manufacturers... can you find anything wrong with that really? Obviously they are in an NPR box, and sent out by NPR (Unless you are saying they are illegally ripping them off) and condoned by them, good enough to put their name on it. Is there any proof that the Chinese made ones are bad?

 

[gofastgeorge]

And about tracing the NPR rings back to Chinese manufacturers... can you find anything wrong with that really? Obviously they are in an NPR box, and sent out by NPR (Unless you are saying they are illegally ripping them off) and condoned by them, good enough to put their name on it. Is there any proof that the Chinese made ones are bad?

The chance of them actually being in a 'real' NPR box is slim to none.....

Look at all the counterfiet Walbro & Bosch pumps, and the horde of counterfiet Denso, Lucas, and who knows what other injectors that pop up on eBay on a regular bassis.
All with 'official paper work, packaging, etc..

If you want to nickel & dime a rebuild, and hope that you have one that stays together,
go for it.