so i may have to go from 84.5mm to 85mm on my benson sleeved boost motor for a few possible reasons. damn cp pistons seem to be in the mid 600 dollar range for a set of 4. it seems that i can save about 100 bucks by buying je or wiseco. id imagine the most power this motor will see is 550whp fuel system limiting me there but most of the time will live on pump gas in the 400-425whp range. i know cps are fantastic ive been using them for years, but are they more than i need for my goals. no matter what brand, im going to try and get something thats like 10:1 compression.

i also noticed that the jes seem to have pretty small skirts on the exhaust side. how does this effect their durability? i think they are all 2618 alloys, id like to run them with a ptw between .004-.0045 at most so god forbid the rings dont seat i can deglaze quick with my 600 grit and keep the same bore. i dont know how much more than 85mm i can/should go on boost and quite frankly am getting too old and increasingly tired of spending tons of cash on my car. i think this could be my last crack at running a high hp motor and trying to crack a 10.9 et before i go on long term leave and try to buy a bigger house with more property..

what do you guys think of this piston situation?

 

Arias

/thread

 

I favor CPs over the other myself, but for customer cars we always use either Weisco or Arias. JEs are a budget piston in my opinion and. Are better trusted in all motor street builds.

 

you think je's are a budget piston? lol.

All of said pistons, arias, je, wisecos, cps all perform great, will take any amount of boost you throw at it... Id use any of these for a 900whp setup. Most are 2618 alloy. wisecos tend to be the cheapest. I bought a set of new 81mm wisecos for 400 shipped, Ive seen em cheaper.

I went with .0045 P2W clearance for my 500whp build.

 

read this whole post..

Wiseco vs CP pistons. Anyones advice? - NASIOC

 

Of the group of brands discussed here; CP,Arias,Weisco etc yea I would say JE is the bargain piston of the bunch.

 

saving the cash on je's over cp's basically gets me a free headgasket with the 100 bucks.

while id love to see 400 shipped, i think that 85mm is gonna be more just for the fact that there is more metal there.

 

Wiseco without question. Much quieter than similar 4032 JE forgings. I have had both at same bore sizes and PTW clearances and disliked the JE's personally.

Either way you need to do more research if you for sure want 2618 or 4032 forgings and which pistons are actually made of what. There is a lot of confusion going on in this thread. If you want longevity and aren't building something like an insane 1000+whp build, 4032 are more than capable. It all comes down to dome thickness, pin strutting, land spacing, etc. You buy the piston specifically for the application...

 

My experience with JE and large ptw are they slap so loud you would think it was rod knock. They are great but loud. And yes I would also consider them budget out of the bunch. The JE also will rock considerably in the cylinder because of the small skirts. If I use them again, I will coat the skirts or use inserts in the skirt to calm it down.

 

I'm a fan of Wiseco, but if you're looking for cheap and effective, have you considered Supertech?

 

i havent considered supertech. id like to build the block stronger rather than weaker who knows what ill do with it in the future. im sure with cp's even with the eagle h beams the block could hold up into the 600's.



this is likely ignorant, but i remember hearing that the srp's were the 4032 and really didnt hold up well with higher power 500+. that kinda had the idea of 2618 in my mind. im not willing to risk strength and durability for 100 bucks. however between 2 pistons of equal power capability could i save the cash?

what power level do you need upgraded wrist pins and not just the shelf ones?

what really happened was 2 years ago when first assembled i had rings that didnt seat for whatever reason. after about 1500 miles i took it apart and rehoned it in the backyard then put it back together. its been running great got me low 11s but it was at .0045 before i honed it and im sure i took a bunch too much off making it loud. i think it was wearing the crosshatch good from what i saw through the bore scope.

 

Can't go wrong with Wiseco pistons. I've built quite a few 85mm Wiseco turbo blocks (including my own, currently at 520whp/349wtrq) and they have been very reliable.

But with only $100 more for the CP pistons, I'd just go that route instead. Sure, it adds up quick, but $100 is nothing when it comes to building a car/engine, IMO.

 

If the truth be told almost all pistons are forged at the Weisco facility and are bought as slugs for other companies to craft.
The JE asymmetrical skirts are made to lower the friction and support the dome under extreme temps and pressure. The combustion pressure does not try to rock the piston but is evenly distributed across the dome at all times. The rocking/ knocking is from the crank and rod yanking it left and right. The rocking/ knocking, is a cold piston at low dynamic loading. That is part throttle or idle conditions that put it through a resonance rattle until warmed or loaded.
F1 motors barely have a skirt at all and run 20000rpm.

Go with what your budget allows and get the PTW right for your application.

 

Whoever told you 4032 forgings won't hold up after 500 - 600 whp is completely full of ****. I was going to rant for a while, but I figure I would just post the first link that Google provided in a search... (read both pages)

General Limitations of 4032 Piston Alloy ? Speed Talk

This is just one of hundreds. I assure you that 4032 can more than handle it's own. It is more about setting proper ring gap settings and PTW clearances than what the forging can handle. This would have to be changed no matter what unless you built it loose to begin with which means shorter longevity. 2618 forgings usually beat the bore up in 30k - 50k or less depending on clearances while 80k - 100k (or less obviously) isn't unreasonable out of 4032. The choice is yours!

 

no need to rant, i am more than capable of admitting i have been misinformed and do not know it all. constantly willing to learn. im sure i read it on here somewhere way back when and just have not looked at buying new pistons for a while to realize the misconception.

i highly doubt the motor will be together for even 30k miles, and if it is this is my 3rd car i only put maybe 3-5k a year on it.
so here is a question about cp's. do they undersize the piston so the ptw is built in at the set bore like 84 or 84.5mm etc?

took the head off today. there was a bit of oil in the #4 exhaust port but the stems of the valves are dry, so id have to assume it was coming from either the hg or the bottom end. found some actual scratches in the bores, and the typical wear on the intake side about an inch wide. that is most likely from cold starts and piston slap correct?

im gonna go read those threads now.

 

& Tyler.

Yep you are exactly right. My JE pistons would slap at idle and just under partial throttle. The second the engine saw load they were quiet.

 

Je pistons and wiseco are the same company,,, most cp employees use to work at je.. Most slugs are from the Dover company.. Personally I would not count je as a cheap piston. I did a case study and facility over view for one of my lean manufacturing courses,, Je was quite a place.. I have used je in two builds and were great. One turbo and one all motor. My brother built a b20 turbo build with wiseco. It's still running strong. I haven't used cp or arias.

 

Yes, but it is a tight clearance, like .0025 iirc
the measurement of the piston will be on the spec sheet, tho..and you may bore accordingly
(if you can find a machinist who can accurately hone, good luck with that)
And it's said that not much comes off with a dingleberry or whatever the backyard hone was. Measure it and see.

 

based off a new piston i had (same cp as in motor currently). the ptw was around .0035 on average. the error here is how much my currently installed pistons wore down.

i measured with the bore gauge front to back (side to side) and intake to exhaust thrust sides and then took the averages. i measured where the ringlands sit at tdc and just above the top of the piston at bdc. all measurements were less than 84.5mm or 3.32677".

#4:
- .00125" intake to exhaust
- .00225" front to back

#3:
- .00125" intake to exhaust
- . 00250" front to back

#2:
- .00025" intake to exhaust
-.00250" side to side

#1:
-.00075" intake to exhaust
- .00200" side to side

those are how far under or tighter than 84.5mm aka 3.32677" the cyls were.
the new piston at similar temp about 25 degrees Fahrenheit measured out at 3.3220" at the very bottom of the skirt

this leaves most of my ptw's theoretically .0025-.0035 ish but again cant assume it true since the installed pistons are possibly worn down a bit. as they sit in the motor they have been installed twice and cleaned with scotchbrite i may have taken a bit off in the cleaning process and then again from wear from running.


ok, are there any pistons that come right at 84.5mm to allow me to really clean up the cyl walls and work my desired ptw into it? im afraid to remove all vertical scuffs ill have to dig into the bore enough that the slightly undersized cp's would open the ptw up too much...i sure as hell wouldnt mid staying with 84.5mm if possible

 

.0015 egg shaped on #1
Did u check further down in the bore also for taper?
If you're gonna take off significant amount tho, maybe u should let a machinist try it with a real hone machine, unless you've had good, consistent results before with whatever tool you are using.
I think it's only about $40.

 

OP, I hope these links can help:

https://honda-tech.com/forced-induct...rance-2904081/


http://www.theoldone.com/articles/en...ata_sheet.html


Another good read:

https://honda-tech.com/all-motor-nat...stons-2721867/

 

the block is still together, im not even sold on taking it apart yet. it had 210 psi compression and didnt really push oil but the head is off to get cleaned up and new retainers. this is the time to do it but im just weighing options and ideas. id rather not have it let go or whatever in the spring/early summer and have it mothballed all year long.

i would probably have a machine shop hone this. the guy i use is good but takes ******* forever it could be there for months. ive honed in the yard a few times all those motors ran fine no issues but they all spec'd out good beforehand. hone and hot tank is a bit over 100 bucks i live in overpriced new york

 

You think $100 is bad for a hone and hot tank? Haha... around here it can be $80 for a hot tank and $20 a cylinder to hone... Just how long were you honing and how many stones did you go through? Just for fun one time on a Benson sleeved block I had we went through a brand new set of coarse grit stones and it only removed like 0.0003 - 5" IIRC. Those sleeves are some hard ****, not like stock sleeves at all. I highly doubt you took off even 0.0001" if you just honed until cross hatching appeared. (YES, my decimals and zeros are all correct.)

 

i have to flex hones, a 320 and a 600 grit. since it was only 1500 miles from the machine shop im sure i used the 600 but it was 2 years ago i dont remember offhand. i usually do 15ish seconds with the drill on foward, then another 15 on reverse. about one up and down per second to get the angle around 30-40 degrees. using a mix of atf and wd40.

 

anyone know of a piston manufacturer that makes them exactly at bore size and not slightly undersized? that could very well let me keep my current bore