NPR Pistons

[Shift_Otaku]

Has anyone bought a set of the NPR pistons and given them a try?

http://cgi.ebay.com/ebaymotors...ories

I know NPR does make OEM parts for other car makes and models.

Im rebuilding one of the KA's I have lying around, and was just going to use the existing pistons because they are in pretty good shape and thier isnt any need for new pistons. But I always see these things around and I am quite curious as to the quality of them. I was just wondering if anyone has tried them before and what kind of luck they had with them.

Edit: After doing some research if found a list of manufators that use them for thier piston rings and such.

"TOYOTA Motor Corporation, NISSAN Motor Co., Ltd., MITSUBISHI Motor Corporation, MAZDA Motor Corporation, HONDA Motor Co., Ltd., ISUZU Motor Ltd., FUJI Heavy Industries, Ltd., DAIHATSU Motor Co., Ltd., SUZUKI Motor Corporation, HINO Motor Ltd., NISSAN DIESEL Motor Co., Ltd., MITSUBISHI FUSO Truck & Bus Corporation, YAMAHA Motor Co., Ltd., KAWASAKI Heavy Industries, Ltd, Daimler AG, BMW AG., MITSUBISHI Electric Corporation, MITSUBISHI Heavy Industries, Ltd., KOMATSU Ltd., KUBOTA Corporation, ISEKI&Co., Ltd., MITSUI Engineering & Shipbuilding Co., Ltd., Hitachi Zosen Disel & Engineering Co., Ltd., Akasaka Diesels Ltd., KOBE DIESEL Co., LTD., HANSHIN DIESEL WORKS., LTD., HYUNDAI HEAVY INDUSTRIES Co., Ltd., MAN B&W DIESEL A/S "

The only question that occurs if these pistons are from the actuall NPR..

Edit(again): Seems like NPR dosen't make pistons. Atleast I couldn't find anywhere on thier site that said they did. Seems like thier just unknown brand pistons being sold with NPR Piston rings.

Im still curious as to the quality of the pistons, but like they said, curiosity killed the KA-T.

Still if anyone has tried them, let us know.

Modified by Shift_Otaku at 4:03 PM 3/18/2009
Modified by Shift_Otaku at 4:09 PM 3/18/2009

[240dx]

Bump.

[seang]

IDK, I think they are the same pistons that come with the Ebay rebuild kit if I'm not mistaken. I would like to compare them side by side with a stock KA piston, particuarly the ringlands.

I have had my eye on the 9.1:1 SOHC Nismo pistons. Now if I only had that job...
Modified by seang at 2:22 AM 10/27/2009

[VRoy]

We have a set laying around the shop we have not be able to use so far(stock size). The ringlands look good. They seem to be a fairly clean casting when compared to the stock pistons. Although looks really dont go to far in the strength department. I would think under "normal conditions" they would be just fine. Ours did come in a yellow box marked NPR with rings and a warranty card. So i don't know if they are real or just a real good fake. Might have to call that number on the warranty card if i can find it.

*edit* Also if anyone wants to know, had them installed on stock rods at the machine shop with the wrist pins they provided. Everything came into spec as per our machine shop. Guess that is a plus. Even though we decided to go with a bigger piston

[seang]

We have a set laying around the shop we have not be able to use so far(stock size). The ringlands look good. They seem to be a fairly clean casting when compared to the stock pistons. Although looks really dont go to far in the strength department. I would think under "normal conditions" they would be just fine.

Good to hear, thank you! "Normal" conditions? Haha, is there such a thing? I must say, even stock pistons seem like they hold up okay. Mine seem alright, and I'm not always easy on it, but if I'm gonna rebuild, why not go with something a little better. I like the idea of not spending a s***load of money on some pistons, and forged pistons are a s***load of money. The Nismo ones aren't that bad at 58 bucks a piece, and I can almost guarantee 99% that those are quality.

I remember DeviousKA ran 91.1mm pistons from a Mitsubishi 2.6. He milled them down to clear the deck, and had 10.5:1 compression with a PDF 404 cam, and said it pulled nicely from 4-6k. He couldn't believe it was a ka24e. The pistons were 25 bucks a piece including rings, which is just fantastically inexpensive. The only part of his theory that I didn't like was that the cylinder walls looked thin at that diameter (91.1mm), and even though he said it went great even after 2yrs of service, I want way more service life than that, like 15 or even 20 years.

Now that I think about it, I wonder how old Devious's budget built KA is doing after all this time. After all, it was build in 2003.

For those of you that don' know what the DeviousKA budget build is, here you go... the car has been running for a week now, and running strong. i picked up my 90 fastback with 105k for 900 and decided to build up the knocking but clean ka24e. i decided to go with a n/a setup because of my type of driving, price, and just plain coolness. the prices for any kind of custom forged pistons are outrageous from my standpoint. i did a little researching and brainstorming and ordered myself some mazda b2600 91.1 bore 36.1 compression ht. flat top pistons with a 22mm press fit pin (very, very cheap ). obviously the pistons will come above deck ht, the bore is HUGE (especially for ka24e), and the pin is 1mm larger. i view all of those as positives . okay first i tackled the deck ht. problem. the edge of the piston (where compression ht is measured) was machined down to allow relief for the headgasket and combustion chamber. the mazda pistons have much lower ring lands then the ka24e as well as 2 2mm compression rings. once the piston was modified to clear up top i noticed the piston skirt came extremely close to the counterweight on crank. after a little die grinder work and piston weighing was finished it has plenty of clearance. the rods were honed out to 22mm (some of the copper bushing is left in) and the pins were pressed in. After many calculations and double checking my c/r is right where i wanna be 10.5:1. my crank was full of plastic shavings due to a shredded timing chain guide, and due to the factory installed ball plugs impossible to clean. the ball bearings plugs were drilled out and allen plugs installed, nice. during this whole process i had been dreading the fact of having to fly cut my pistons (myself most likely ) to accomidate the tall compression ht. as well as my pdm c.404 cam. well after a little rediscovered fun with some modeling clay, i find out i have over .080" of piston to valve clearance (exhaust valve, intakes clear by a mile) so that really cheers me up. the rest of the engine was rebuilt and had performance grind on the valves, no porting, stock exhaust manifold. i had to buy 3 headgaskets to get the fit that i wanted and finally settled on the ROL. i bought new headbolts and a steel-backed timing chain kit. i put it in last week with some new injectors and super-nice k&n filtercharger system. i hope to get it on the dyno soon with some ecu and fuel tuning. i am mixing my own gas. i have a 90 coupe that was rebuilt recently and i thought it was fast. this engine pulls so hard from 4000-6000rpm is is unbelievable it is ka24e. total cost ~700 including cam, pistons, machine work, and the rest of rebuild kit
Modified by seang at 10:09 PM 10/28/2009

[seang]

Here are some NPR's I found outside the rebuild kit. 130 dollars including rings and piston pins. Up to .040 (1mm) oversize.http://www.perfectengine.com/N...6.htm

Now if I only knew how much the head could be shaved...