npr pistons

[hornet7288]

I bought some 20 over npr pistons off of ebay for my turbo build. I have heard that these are known to break apart under boost loads that are not incredibly heavy. Is this true and if so what is a good set of pistons to put in that are a fairly decent price?

 

[bombinuass]

i dont know much about them at all, but if what i read is correct, npr is what comes OEM in a gte? i may be wrong but maybe someone can help me on this...

 

[hornet7288]

I just want to make sure that this is true and it didn't happen to one person and that's what I am hearing about.

 

[bombinuass]

i understand. how much more work you got left?

 

[hornet7288]

other than possibly getting new pistons I am just waiting on the MHG to come in and I should everything. Here are some random pics of the build.

 

[bombinuass]

wow thats clean looking, who machined the block? hp goals? build thread coming? how come you missed the meet!!!??

 

[hornet7288]

school has had me really busy. I am just going with a stock CT, but if I could eventually do 350 to the wheels on an upgraded ct i'd be happy. It will be mostly stock besides a 3 inch full exhaust with ddp. I got some ARP head bolts and the mhg of course. I don't want to blow the head gasket haha. Hills machine shop near warner robins. They did a really good job on everything!

---------- Post added at 01:59 PM ---------- Previous post was at 01:58 PM ----------

and yea I am going to start a build thread once things start moving a little faster. What is going to kill me the most is not having all of the right bolts.

 

[bombinuass]

talk to metaphysico he just parted out a parts car and may have the bolts you need. when i need them thats where i go lol. but he may not but its worth the shot too see. you had the 3in exhaust at the last meet right? or was that not your car and your the one that was riding?

 

[stevenr816]

Could have always spent 300-400 on semi forged probe pistons. But my friend didn't crack a NPR till 21psi on a 60-1 racing a c5 vette

 

[hornet7288]

talk to metaphysico he just parted out a parts car and may have the bolts you need. when i need them thats where i go lol. but he may not but its worth the shot too see. you had the 3in exhaust at the last meet right? or was that not your car and your the one that was riding?

that was my roommate. He has 3 inch full exhaust. I had my supra out at the meet but decided to ride with him to helen. I have the black 89.

---------- Post added at 02:55 PM ---------- Previous post was at 02:53 PM ----------

Could have always spent 300-400 on semi forged probe pistons. But my friend didn't crack a NPR till 21psi on a 60-1 racing a c5 vette

wow...looks like I should be ok

 

[bombinuass]

ahh ok. i remember now. cool, well hope to see you at the next meet for sure.

 

[super.secret.supra.club]

i broke a set that was thermal coated. 1,3,4,5,6 pistons had cracked ring lands. i pulled it apart yesterday and putting in some probe pistons.

 

[hornet7288]

i broke a set that was thermal coated. 1,3,4,5,6 pistons had cracked ring lands. i pulled it apart yesterday and putting in some probe pistons.

what kind of mods did you have done?

 

[dubsupra209]

check out my build thread ive been running 9psi on 57trim no problems here...ive already put 10k on them

 

[mecevans]

Sounds like you had a fuel problem to crack nearly all of them. Im stuck between NPR or Clevite/Mahle pistons. The NPRs come coated thought.

 

[hornet7288]

I don't want to put them in just to crack one or a few of them, but it sounds like these crack if something goes wrong. They are on the cheaper side so I got worried that they would not do too well because of that.

 

[northwestsupra]

Sounds like you had a fuel problem to crack nearly all of them. Im stuck between NPR or Clevite/Mahle pistons

Or extremely bad luck with a bad batch

sent from my ultimate droid

 

[stevenr816]

that was my roommate. He has 3 inch full exhaust. I had my supra out at the meet but decided to ride with him to helen. I have the black 89.

---------- Post added at 02:55 PM ---------- Previous post was at 02:53 PM ----------



wow...looks like I should be ok

Ya his cars basically a full hks catalog 7m so the electronics are kinda old. With think it's from heat soak, hugh egts, and knock. The hks stuff doesn't change any timing and the hks exhaust is pretty restrictive

 

[D.J.T.]

You should've bought CLEVITE pistons. I got the stock replacement ones. Shouldn't be hard to find a official retailer in your location. I live in Arkansas at the moment & I found one in Arkansas.

 

[supraguy@aol]

Could have always spent 300-400 on semi forged probe pistons. But my friend didn't crack a NPR till 21psi on a 60-1 racing a c5 vette

Semi-forged?