supersal

iTrader: (1)

I think a lot depends on the tuning and set-up of the cars - most of my experiance is with in-line fours and not Subaru boxer engines so I cant speak for failures on them but in the Turbo Opels I've had we have seen factory Mahle's last just as long as 2618 pistons m aking similar power... There are also stock Evo pistons holding plenty of power on good knock free tunes...

But to each their own - like I said I got nothing against 2618's have run them before without issues on a couple of my motors...

.

RSMike

iTrader: (1)

I'm sorry, i didn't realise JE and Wiseco do 4032 alloy pistons. I googled it but didn't come up with anything.

I will look into JE models, But they do not offer a 86mm bore is the SRP Pro series. I'll ask for a "normal" 4032 piston.
Supertech do not make a 86mm piston for 100mm stroke.

Ok here are some numbers

EVO130385I19 - Mahle 86mm bore, 100mm stroke, 22mm pin, 9:1 comp ratio, 280 gram.
http://www.us.mahle.com/C1256F790053...20complete.pdf

K596M86 wiseco 310gram. 9:1 comp ratio

k627m86 wiseco 1400HD 305gram. 9:1 comp ratio
http://www.wiseco.com/Catalogs/ProTr...eteCatalog.pdf

Mahle pistons look very nice!
And very light!!

laramie_05MR

iTrader: (20)

I use Mahle as well in all my builds. Import and domestic.

RSMike

iTrader: (1)

JE have replied back stating that a 4032 vs 2618 only expands 15% less. Very Negligible.
Piston to bore clearance is recommended at 3thou, with people running them as low as 2.5thou with 500hp and very good tune.

My tuner runs his HKS pistons at 0.04mm clearance! 1.6thou!
And having it this tight, there is LESS wear on the skirt because less of a chance for them to rock in the bore.

Looks like Mahle it is, they have recommended clearances from 1.6thou to 2.4thou.

RSMike

iTrader: (1)

I got very very comprehensive email replies back from Mahle.
I have decided to try them.

If you want more info i can post here and/or PM you.

Cheers, Mike

RSMike

iTrader: (1)

My 86mm Mahle pistons have landed.
They are a very nice piece of kit!
277grams each, 122grams per pin.
411grams total (piston, pin, retainers and rings)

Does anyone know if the Mahle pistons are made to suit 1mm oversize valves as standard?

Also the piston to bore clearance is 0.002" to 0.0024" straight out of the box (assuming 86.000mm bore). I measured them myself.

wreckleford

iTrader: (2)

Pics?

RSMike

iTrader: (1)

i can get some for you on the weekend. Will update the thread then.

sparky

iTrader: (1)

I can't wait. Don't forget to post up those pics, GL

RSMike

iTrader: (1)

Are there any pics you want specifically?
I.e. how the 2nd ring land lower support (i.e. crank side of 2nd ring) is actually a smaller diameter than the top ring land? (why the hell do they do that? lol)

ZMX

They make low expansion pistons. They're called hypereutectic. They break more easily.

Why do you want that?

RSMike

iTrader: (1)

They (Mahle) make both kinds of alloy pistons (2618 and 4032)
Yes they break more "easily" than the softer 2618 alloy.

Does that worry me? No.

I like the tigher piston to wall clearances. 3thou, yes please

ZMX

The piston to wall clearances on a 2618 piston won't be small once it's heated up.

btw, 4032 alloy pistons aren't hypereutectic. They won't best fit your standards of cool engine PtW clearance (I still don't know why you care).

SeanC

iTrader: (7)

The SRP Professional series pistons above from JE were specifically made for street cars in the 500hp range and under. If you're looking for a high quality, forged piston for your street car...these are the ones. These parts were a clean sheet design, designed using finite element analysis with the specific load conditions experienced in our engines. AMS has them listed here:

http://www.amsperformance.com/cart/J...r-Pistons.html

I'd say the SRP Professionals are the perfect street pistons but for that and everything else JE now has new asymmetrical pistons. They require less clearance, are very light, use 2618 alloy and are designed for heavy side loading associated with turbo engines. These parts have a contoured undercrown (thicker in center) that better handles the heat from combustion, an offset wrist pin (quieter and balances the piston), brushed crown (reduces likelihood of preignition) and uses a shorter stiffer wrist pin. Here's the latest info:

http://www.jepistons.com/Articles/10...d-Pistons.aspx



Both Buschur and AMS are using the asymmetrical parts...