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NPR versus OEM Piston Rings?


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I joined today just so I could look for old posts of any bad experiences anyone might have had with NPR rings, then learned your search engine has some kind of weird rule against three letter words like "NPR" or "OEM" :wacko:

I have two '97 EJ25 DOHC motors sitting in my garage and a Kennedy Engineering VW adapter kit ordered for my rail buggy. The first motor was a running 200k+ mile 97 Outback that I bought for $300 with brand new tires on it and stripped all the way down to just a running wiring harness and motor- But I think it was leaking some oil and/or coolant onto the top of the block under the intake, probably from a head gasket, The other motor is a pick-n-pull engine, very clean but hit in the front and busted up a little around the pulleys and covers, also has some Northern rusty bolt issues around the timing covers. I'm aware I could run into some bent valve issues on it...

 

I'm trying to do a quality minor overhaul on the p-n-p engine and save the other one for parts, and I ordered a digital Suby Service Manual link on Ebay today. So far I'm looking at ACL bearings and either Fel-Pro or Ishino gaskets.  My question is whether I should pay $170 for OEM rings, or approx $45 for the NRP ones? (1/4 the price). Its a stock build that will probably never be stressed since it should have 3 times the power of the old air cooled motor I'm running now. I like to build things right the first time and have it run for years, but am also on a tight budget. Will a set of NPR rings last just as long as the OEM ones, or is it worth the piece of mind of putting the OEM ones in now and not worrying about them again? Has anyone had any experience with a set of NPR rings that wore out/started smoking sooner than they should have?  I found multiple posts about this same question on honda-tech.com when Googling it, but for some reason my computer wouldn't actually open any of the discussions...thanks..

Edited by donbarnes
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Another question I had about the NPR rings is whether they are all the same for a specific application, or could there be different levels such as cast/moly/chrome, ect ? For example, if looking at NPR rings on Ebay for the 96-99 DOHC 2.5, should all the NPR listings be the same set?

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I hadnt found any bad reviews on them either, but hadn't found anybody talking about how many miles they got on an engine with them. Nowadays a lot of people seem to think all rings are the same, but years ago a guy I worked for used to buy those old $100 rebuild kits for 350 Chevys and they would be smoking again within a few months, but my stepdad built a motor for him and insisted he get genuine rings from the dealership- And twenty-some years later that old 2-ton truck is still on the road, so I guess I'm a little biased toward OEM rings and leary of something that is way cheaper than OEM...

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id use them make shure you reberring the engine as the berrings are way weaker on it than the rings and new rings will put more load on the rod berrings i use aftermarket rings all the time try to make shure they are made in japan. I do use alot of hastings rings and top line both seem to work fine. Also the drilled oil ring feed holes get pluged up must be cleaned out and if the pistons are scratched i knurll them or replace them or they will slap

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I plan to put new ACL bearings in it, haven't decided yet on the rings- I suspect that I would enjoy saving $100 on them right now, but a year down the road I would be wondering whether were they really as good as good as OEM.. I got the right side head off this morning, the one that had the upper pulley broken in a wreck, and everything looks good. No scuffing or marks of any kind to indicate a valve touched a piston on that side, and it already had a 4-layer MLS head gasket on it- so I'm assuming someone has been into it before...it is also very clean on the outside, has a little bit of white powdery corrosion scattered around on the aluminum, but no oil...

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carefull have had many bent valves that did not look bent spin them in a drill and you will see or have them ground i have a valve grinder and you see a bent on right away when it up to the stone. I realy like the hastings rings no problems and have many new engines with over 100000kms on them 0 smoke /blowby

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Two of the valves on one cylinder have a slight mark on the piston and the valves where they made contact after the wreck, and when held to the light just right I could see light shining through where they aren't seating correctly, so will have to change those two... I got it all disassembled last night and one of the pistons had just a little bit of scuffing on the side, I wouldn't have thought twice about putting it back in most of the engines I've done, but since these have a rep for piston slap and I don't know what causes that, I went ahead and ordered a new set of NPR pistons and rings- couldn't find any negatives anywhere on them..

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I got in a set of the NPR pistons yesterday and they looked good, coated skirts, and the piston rings looked really good. But I had some concerns with them being in a plain yellow box with no brands and no country of origin, so I emailed Mizumo Auto that I got them from. They answer emails immediately, and said they buy palletts at a time directly from NPR, and some of them come in the plain packaging and some with the brand on it, but are the exact same parts. Without me even asking her to do anything the lady said she was Next Day Airing me a set with the brand markings and a return label to send one set back. To me thats some amazing customer service..

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