nippon pistons?

[MellowVR4]

What do you guys think about these pistons, their on ebay. I just wanna see if anybody has had any luck with these piston. Let me know

 

[Andy_S]

I used them. Nice pistons. Word on the street is they are the same pistons made for manufactures, but with different packaging.

 

[MellowVR4]

they didnt crack, or pop a hole in it right, no lose of compression

 

[Andy_S]

Well thats what the stock pistons did. I haven't had much time on these since I rebuilt the motor, so they haven't really been able to prove themselves in my case. They did seem to be made well and the rings where very consistent. Install went smooth and engine has perfect compression after break-in. For the price, they are very good.

 

[belize1334]

If you shop around for OEM pistons and compare pictures you'll see that they are in fact NPR pistons.

 

[MellowVR4]

so they are basically oem pistons.

 

[MellowVR4]

im gonna buy some stosk evo8 pistons, i heard these come forge from the factory, and they have a compression of 8:8.:1.

 

[belize1334]

^^ That's true. The only problem with them is that the engine spins the opposite direction so the pins are offset to the wrong side. You can flip them around but then the valve clearances are mismatched. People have run them with no problems but there is a theoretical "flaw" in the design when putting them in a 6-bolt.

 

[MellowVR4]

Has anybody had any problem with these evo pistons in your 6bolt with this theoretical flaw? BELIZE1334 what do you have to flip the piston or the pins in order to make this work.

 

[belize1334]

Point of clarification...I haven't done this. I'm simply relaying the info that I gathered when I was thinking about doing it.

My understanding is that the wrist pin sits slightly off center in order to help even out the wear on the cylinder wall since the rod is in a different position on the way down during the combustion phase and thus one wall bears more side-load than the other. Because Evos sping in the opposite direction as DSMs, the wrist pin offset is on the opposite side of the combustion chamber (ie firewall vs. radiator). To fix this, you simply flip the piston around. But that means that the piston dome is seeing intake valves where it expects exhaust valves and vice-versa. You don't have to DO anything other than install the pistons backwards. The machining of the 1G rods goes just like it would with 2G pistons and the install is the same.

It's just that there is a theoretical mismatch of the valves to the dishes which causes...I don't know what. Maybe it's more knock prone... Maybe you're more likely to bend a valve if the timing gets bumped by a couple of teeth...

 

+1 ^^^ I've seen it done, it's doable. but like belize1334 said, it's technically not correct.

 

[Vman911]

I'm running a set of evo8 pistons and rods in my car right now. Except I have a 1G 7 bolt motor. Yes the pistons index the opposite way. Arrow pointing towards the back of the motor.
The evo rods are pretty much the same as 2G rods. So to put them on 1G rods I believe the wrist pin needs to be bigger.

 

[MellowVR4]

Quoting belize1334:
Point of clarification...I haven't done this. I'm simply relaying the info that I gathered when I was thinking about doing it.

My understanding is that the wrist pin sits slightly off center in order to help even out the wear on the cylinder wall since the rod is in a different position on the way down during the combustion phase and thus one wall bears more side-load than the other. Because Evos sping in the opposite direction as DSMs, the wrist pin offset is on the opposite side of the combustion chamber (ie firewall vs. radiator). To fix this, you simply flip the piston around. But that means that the piston dome is seeing intake valves where it expects exhaust valves and vice-versa. You don't have to DO anything other than install the pistons backwards. The machining of the 1G rods goes just like it would with 2G pistons and the install is the same.

It's just that there is a theoretical mismatch of the valves to the dishes which causes...I don't know what. Maybe it's more knock prone... Maybe you're more likely to bend a valve if the timing gets bumped by a couple of teeth...



So just have the evo pistons pointing the flywheel side instead of the timing side. or have the arrows pointing the timing side little confused. /ubbthreads/images/graemlins/dunno.gif

 

i though both engines turned clockwise like everything else but honda engines. its the head being reversed that causes the valve reliefs to see the wrong set of valves. am i wrong?
wiseco catalog says that the 2g eclipse and 03-07 evo use the same piston but the evo ends up with higher compression. the pistons are also marked with a dot that needs to be oriented towards the timing side. so it seems to me the pistons dont need flipped around.

 

[MellowVR4]

so just install them as i would install a set of 2g pistons with the arrow pointing to the timing side, as the 1gs 6bolt pistons arrow points towards the timing side.

 

thats what i would do. anyone else?

 

[524of1000]

Broxma has a write up on how his were done. He's running evo8 pistons on 1g rods...

 

[MellowVR4]

i dont wana put these pistons on the wrong way, that will suck.