AAN Stock Pistons

[Jcarrick]

So I've gotten some mixed review on what the stock pistons can handle. I know rods will do up to 400whp, but gonna replace those with some forged rods. I've been told that the stock pistons will handle 600whp. My ultimate goal with this motor is between 450-500whp. Should I replace the pistons, or will the stock ones do just fine?

[JP]

You'll need to drop compression using either stacked gaskets or an off the shelf thicker gasket to make 500whp otherwise you just can't run enough timing advance on stock pistons to get to that figure. The pistons will take it if they are the forged ones.
Depending on the year of production of your engine will dictate whether they are forged I5 pistons and or cast ones as used int he later years.

600whp I haven't personally seen anyone do I've seen 600flyhp which equates to a high 400whp so yes end target of 400-500whp is achievable providing they are the forged pistons.

hth

[rash]

I know a few cars with stock pistons and over 500HP and one with +700HP on rollingroad...

[Jcarrick]

RWD19T,
Mine is a 1993... Would this have the forged pistons in it? How would I know what pistons it has?
And yes, I will probably end up drilling the rivets out of the head gaskets and stacking them.

Rash,
I've heard the same thing. Thats why I'm wondering if I need to put new pistons in it when I do rods? The most I would want out of it is between 450-500awhp

[Jamo]

The pistons themselves can handle the power, what you are talking about is can the engine at that compression ratio make power with the timing without detonating.

Two completely things that are being confused.

As said use a compression dropping gasket from 034 or skim the pistons taking CR down to 8.5 and the stock pistons setup will make your power.

[JP]

If it's a 1993 definitely forged.

Can't see any issues with big power figs on them providing ignition timing is correct and fueling is correct.

[euro_urs4]

just would like to add to this topic i have a 1994 audi s4 aan, would this motor also come with the forged pistons?

[Rocco]

just would like to add to this topic i have a 1994 audi s4 aan, would this motor also come with the forged pistons?

+1 for know about the July of 1992 3B engine

i did not knew nothing about diferent pistons installed in our factory engines..

[JP]

^^^^ iI couldn't be 100% but so far the only engines I have found the cast pistons in are late 1995/96 AAN engines in the UK. Where they have are a considerable weight difference of around 10 grams and a different manufacturers stamp on the underside. Yet they all have the same part number from Audi go figure

[twoqu]

^^^^ iI couldn't be 100% but so far the only engines I have found the cast pistons in are late 1995/96 AAN engines in the UK. Where they have are a considerable weight difference of around 10 grams and a different manufacturers stamp on the underside. Yet they all have the same part number from Audi go figure

Not wishing to discount what you have found and indeed measured but are you sure these other pistons are not also forged?
I would guess that there were two OE suppliers, KS and Mahle. It would not make any economic sense to tool up again to produce inferior cast pistons for a limited and short production run.
I have seen pics of both and I seem to remember that the Mahle ones has simplified valve relief cutouts than the KS and differences to how the bowl was machined. Whether that accounts for the 10g difference or not I don't know!
I have only seen KS ones in stock engines although its possible that Mahle was used towards the end of the production run if the ones you have seen are stock sized.
There are bound to be pics on here somewhere of both types of piston!

[chipsenter]

Zero problems pushing out 500+ hp on stock pistons ! I had 620 Whp stock pistons

[chipsenter]

Its a reason the lemans race diesel cars have the MAHLE logo in the front

Keep pushing eh.

No need to buy expensive forged pistons when u allready have it mate.

[Rocco]

Its a reason the lemans race diesel cars have the MAHLE logo in the front

Keep pushing eh.

No need to buy expensive forged pistons when u allready have it mate.

and do you know how long could be the original pistons life with more than 500hp??

or they are for ever if the engine work always perfect ?? piston rings will have to be replaced and upgraded true??

[chipsenter]

Ofcourse the rings should be replaced and polished to correct measures.

We got guys over here pushing over 650 easy on stock pistons.
Its good ****, only disadvantage is the valve pockets in stock pistons. ur not able to have high lift on cams. my last cam adjustment with 7A cams 2,2mm Intake cam 1.6 Exhaust cam from this setup u will get nice respons and fast spool up

Good luck eh.
J

[Rocco]

and did you skimed them for get lower compression ratio??

9´3:1 it is the original CR...so how many distance to skim for 8´5:1CR with the same 144 rods and original metal head gasket??