NPR Pistons and Rings. Good for a turbo application?

[LuizHGato]

Hey guys. I've bought these pistons with 9CR and serching on web i read that they weren't for turbo applications.
I'm gonna use a 16G turbocharger with ethanol (E100) with 25PSI and i'm aimming to 450HP. The higher CR is what I need because of the ethanol.
Will it work well on this build? Are these pistons durable?
Here are pictures of them:

http://img690.imageshack.us/i/95964117.jpg/
http://img193.imageshack.us/i/22804012.jpg/

Thanks!

 

[4g64fiero]

This is really interesting....

I wonder if these are the pistons from the EDM n/a 4g63 2g eclipses....

Are these going in a 7 bolt? You need to make sure the wrist pin is the right diameter. If so, I would measure the ring land and compare that to a stock USDM turbo 7 bolt 2g piston and if its the same, I would use them.

NPR is a good brand.

 

[Bender]

They will work for a turbo application, but you wont be able to run as much boost or timing because they give you a higher compression ratio.

With that said, genuine NPR pistons are probably the highest quality cast pistons you can get.

 

[LuizHGato]

Well. I'm gonna use them inside a 1G 6bolt engine because I'm trying to get more CR to use 100% ethanol. This fuel don't run good without higher CRs.

I saw that NPR (nippon piston rings) is another brand instead of Nippon Racing. The first one is chinese (taiwan) and the second is Japanese. What about the quality of them?

I saw ITM ones being sold 1 by 1 and the price is almost the same. Could you compare them?

4G63 N/A Pistons Set 1989 - 4/1992 Mitsubishi and Hyundai
4G63 Piston with rings N/A, All normally aspirated engines

If I was able to run gas, I'd probably use the original ones but with ethanol I'm gonna have too much problem on low rev and to tune it by myself.

Thanks for your help.

 

[fastbike02]

I bought a set off ebay for $98 shipped. They look just like OEM except they don't have the mitz logo on the side. I hope they hold up for my 275-300hp build!

 

[whiteboyz]

I bought a set off ebay for $98 shipped. They look just like OEM except they don't have the mitz logo on the side. I hope they hold up for my 275-300hp build!

I bought the set you are talking about, and The Dsm Graveyard sells the same set aswell. i have about 100miles on the rebuild and so far so good . the quality looks good.

 

[donniekak]

Do all of you realize he bought non turbo pistons? They should work ok on e-85, but any cylinder pressure spikes will crack a ring land.

 

[4g64fiero]

Do all of you realize he bought non turbo pistons? They should work ok on e-85, but any cylinder pressure spikes will crack a ring land.

Thats what I was getting at in my first post.

Are these pistons 2g EDM n/t or are 1g 7 bolt usdm n/t?

This matters, the wrist pin is a different diameter.

 

[donniekak]

Thats what I was getting at in my first post.

Are these pistons 2g EDM n/t or are 1g 7 bolt usdm n/t?

This matters, the wrist pin is a different diameter.

They are stock replacement 2.0l 1g n/t pistons. 92.5-94 were 7 bolt.

 

[4g64fiero]

If thats the case, I would sell them^^^^.

 

[Bender]

If he gets a spike on alcohol it is going to crack a ringland on any cast piston. Doesn't matter if it is turbo or non turbo.

 

[LuizHGato]

Well, the seller sold them for 6bolt rods.
You guys are saying that they won't work because of the pressure/hp or because of the fuel?

Because ethanol needs higher CR and have a better cooling property.

If they won't work with this system (16G turbocharger trying to get 450HP), I'm gonna pass them.

I'm just trying to avoid a worse product then stock ones, that are known to work well with 500HP.

Thanks!

 

[4g64fiero]

The n/t pistons are weaker. Their ringlands are thin and prone to cracking from even minor detonation at low boost.

 

[Bender]

Granted they are weaker, but E85 doesn't knock. It just goes straight to blowing up. In that case, whether they were turbo or nonturbo pistons, it wouldn't matter. You want to use forged pistons with E85 for that reason. It can be done with cast, but it will be a time bomb either way.

Also, if you use E70 or E78, you can get knock, but that is not what I am talking about.

 

[TofastForU_99]

NPR's are great pistons. if you dont want to break the bank definitely go NPR.

 

[LuizHGato]

Like you guys said, or I could understand, these pistons aren't a good choice for my project as they are weaker than stock ones.

There's another alternative that is buying from JNZ tuning MD129922, that are non-turbo pistons but are OEM Mitsubishi (Nippon Racing).

So now, these ones will resist for 450wHP on E100?

 

[Bender]

I would say these are stronger than stock ones. It's just that I wouldn't run E85 on cast pistons.

 

[4g64fiero]

Huh? NPR is oem. OEM n/t is nowhere near as strong as turbo OEM pistons.

Can you clarify what your saying?

 

[donniekak]

I would say these are stronger than stock ones. It's just that I wouldn't run E85 on cast pistons.

You must be confused. The only way to run high boost on cast pistons is e-85, or race gas. I run 30 psi daily on stock 1g pistons, i also have knock retard disabled in my ecu. I would only do this on alcohol.

 

[Bender]

You must be confused. The only way to run high boost on cast pistons is e-85, or race gas. I run 30 psi daily on stock 1g pistons, i also have knock retard disabled in my ecu. I would only do this on alcohol.

I have been tuning for over 6 years, and I have a vehicle in which I run alcohol. I am in no way confused. The problem is that E85 doesn't knock, so you wont get any warnings beforehand. It will just go straight to blowing up. With cast pistons being weaker than forged, if you get any of these spikes from E85, it will crack the piston. I am not talking just about running lean. If you have a dirty injector with an improper spray pattern, or even if you are running too rich, the alcohol will puddle on top of the piston, and detonate all at once when spark is introduced.

Huh? NPR is oem. OEM n/t is nowhere near as strong as turbo OEM pistons.

Can you clarify what your saying?

IIRC, NPR pistons are coated, whereas OEM are not. Granted, there is less support on the ringland in N/T pistons, and they are weaker than turbo pistons. IMO (again, my opinion.. I can't prove this) is that if you run into trouble running alcohol, it will break a cast piston.. whether it be a turbo design or non turbo design. For this reason, I only recommend forged pistons when running E85, E98, or E100. E70 and E78 wouldn't hurt by seeing forged pistons, but should work fine with cast. However, this is not what I am talking about since the OP specifically said E100.

 

[mobythevan]

It wouldn't bother me to run on cast pistons, I am doing it at low boost 14psi on 12:1 compression. I would be careful with tuning and take it slow on timing and boost. Otherwise it isn't hard to change pistons when they crack up so I would go for it. I bet it will last longer than you think on E85. Just my 2 cents. I am all for experiments, even if it causes cracked pistons. Makes you cautious on tuning.

 

[KelTsi90]

I'm using these pistons for more than 1 year holding 28-30psi of boost. The car is my DD. They are in excellent shape. Still have 155 of compression. They are a good option.

 

[ramsack]

NPR are the ones who originally made our pistons. i doubt they would be allowed to get 4g63 cast into them (like what you see when you crack open an original engine) if they didn't. they don't come coated, but they make them coated as well.

i would stay away from non-turbo pistons on a turbo. just not good news. once i tear my engine down in the future we will see how mine held up.