As the title mentions, which pistons would you choose for your engine builds? I'm mulling over which pistons to choose for my personal engine build. Can't really decide between the two different choices of alloys out there. 4032 or 2618. On one hand, the strength of the 2618 alloy is great, the piston slap brought on by the greater clearances required isn't. Will the 4032 alloy pistons stand up to constant boost levels of 2.0 bar?

I'm not talking about the various pistons as supplied by the many vendors on the EvoM forums, but more regarding the different manufacturers and their choice of alloys. Please vote and explain your choice.

Thank you

 

I chose the wiseco because they are being used currently and in the past of several built 4G63 short block motors in the 400 and up HP range. Their top design has been also been said to help the EVO with the 5000-5500 rpm knock sensitivity. I am only choosen these though becuase of the proof I have seen. I can't really speak for the others first hand.

 

Here's an interesting article I came across while researching Venolia pistons. It's somewhat specific to the 3000GT/6G72 motor but I'm sure 90% of the information applies.

http://www.stealth316.com/2-pistonguide.htm

In short, 4032 alloy is a silicon-aluminum alloy. It has better wear characteristics but if in the case that a crack begins due high stress, it won't stop cracking until catastrophic failure occurs. 2618 alloy will wear more quickly but if it begins to crack, the crack will travel to an area of lower stress and is less likely to suffer catastrophic failure.

One interesting tidbit of information on that site is the mention of hypereutectic cast pistons. This is the stock Evo piston type. The high silicon content of these types of pistons leaves them very brittle and prone to breaking when subject to detonation.

Anyway, I'm bench racing here. Flame away.

 

You are correct so you kind of give one for the other, the 4032 will last a lot longer but if they fail they will go all the way. The 2618 won't last but 30-40k at the most and if they crack they can keep taking some abuse before they kill other things. This is why you are seeing people with broken pistons, it is from detonation probably 80-90% of the time.

 

Ross makes a piston with a off set pin. It's a bit quiter on start up with less piston slap. I'm sure it will hold anything your throw at it.

Eric

 

I use the Pruven / Arias pistons - had them in my engine for 13,000 miles of 500 plus whp use and many drag events - they looked like new when I took them out - they get my vote

 

Truth

 

are you doing this buildup yourself or having someone do it? If you are paying for it to be done, use whatever your machinist recommends...that alone pays big dividends if there are issues down the road.

 

Probably just me and a mechnically inclined friend.

Machinist here doesn't really have any preferences, just as long as its forged. I guess they are more like a machine shop where they follow the specs given and do the work accordingly.

Previous experiences with 2618 alloy pistons have had problems with oil consumption. Guessing that the machine shop went with the larger clearances, but dun wanna take chances with that, so I'm trying to draw on the experiences of the members here and find out if what pistons have worked for them.

Cheers

 

I've used Arias and Ross in my own cars without incident - no unusual "slap" - this is exactly why I have never liked the JE's...every one I have heard has been noisy, though without knowing the skill level of the person doing the assembly, it's a shot in the dark to some extent.

JUN uses Cosworth pistons (I now because we are a dealer), Tomei I can find out - have to talk to them tonight anyway

 

Cosworth = yummy!

 

i second that, that's why i chose Jun. But at a price of 1500 for a piston set i think i'll pass.

 

CP is really good as well.
that's what i use in my motor

 

anybody know the difference between the ross and wiesco pistons?

 

My mate used Arias 4032 pistons on his EJ25 build and it's been pretty good so far. No unusual piston slap ala JE and it's been holding 1.8 bar (26.5 psi) no problem. He tried Ross on his previous rides before and has nothing but good words for them.

Tomei pistons are pretty popular where I'm at, but as with JDM parts, expensive, but they definitely work for sure. Just saw an Evo with their piston/rod combo on the dyno running 2.0 bar (29.5 psi) and it was holding up no problems, quiet as hell too. I know their GT-R pistons are very popular since they have that 'cooling-channel' design on that series of pistons but don't think Tomei has that option on the Evo though. So what have you heard from Tomei?