Forged OEM piston?

[Evoluzione]

Does anyone know what car manufacturers and their engines had forged pistons fitted as standard?
I've found that Saab fitted them to the B234 engines, any more?

[AntiLagGC8]

Various Impreza's have had forged pistons.

There's been quite a lot over the years. I can't list all of the models as it will take some fact checking but examples are 22B, P1, Type R and various versions of the STi but not all models.

[Evoluzione]

AntiLagGC8 said:

Various Impreza's have had forged pistons.

There's been quite a lot over the years. I can't list all of the models as it will take some fact checking but examples are 22B, P1, Type R and various versions of the STi but not all models.

It would be good to see a piston from one of those if you knew which one it was.

[AntiLagGC8]

Evoluzione said:

AntiLagGC8 said:

Various Impreza's have had forged pistons.

There's been quite a lot over the years. I can't list all of the models as it will take some fact checking but examples are 22B, P1, Type R and various versions of the STi but not all models.

It would be good to see a piston from one of those if you knew which one it was.

Something like this?

http://www.airpowersystems.com/us_spec/subaru/sti/...

[PhillipM]

Honda s2000 pistons appear to be forged from the factory, as do the rods and crank.

Edited by PhillipM on Sunday 13th March 00:55

[BrownBottle]

I think there's been quite a few, currently the Peugeot RCZ R has them.

[Pumaracing]

Vauxhall XE 2.0 had forged pistons.

[anonymous-user]

some VAG 1.8t variants did with cranks and rods too.

[DVandrews]

Cosworth YB....

Dave

[Boosted LS1]

OP are you sure the saab has forged pistons? I know they use mahle's but didn't think they were forged.

[Evoluzione]

Boosted LS1 said:

OP are you sure the Saab has forged pistons? I know they use Mahle, but didn't think they were forged.

No they aren't forged, i've been given some duff information. I was chatting to resident Saab expert Mr Kitten earlier who confirmed it too.

[Pumaracing]

From a pic I found online yesterday the B234 piston is clearly a casting not a forging.

http://www.saabcentral.com/forums/showthread.php?t...

[Boosted LS1]

I think the ls9 has forged pistons but I've not opened one up yet :-)

[Evoluzione]

Boosted LS1 said:

I think the ls9 has forged pistons but I've not opened one up yet :-)

Aye, that's no chuffin use to me though is it

[Evoluzione]

Pumaracing said:

From a pic I found online yesterday the B234 piston is clearly a casting not a forging.

http://www.saabcentral.com/forums/showthread.php?t...

Yes I found the same and similar pics myself.

Some of the very specific suggestions are good (like the Vauxhall XE) so thanks to all who posted, maybe I can try to find one of those so I can measure it up. I do need one (probably good, used) in my hand.

[Pumaracing]

What is it you're trying to find out or achieve?

[jontysafe]

DVandrews said:

Cosworth YB....

Dave

These were pressure cast Mahles like the Saab

[Pumaracing]

There seems to be a lot of bum information in this thread. It's very easy to tell if a piston is cast or forged by looking inside it. The internal shape on a forged piston is made by a single piece tool so there can be no undercuts (that aren't machined in later), the entire internal surface of the piston will be smooth and without split lines although there may well be part numbers which are engraved into the forging tool.

Cast pistons are shaped by a multipiece tool consisting usually of either 3 or 5 sections.

The piston on the left is cast and you can see a split line running just this side of the far gudgeon pin boss. There will be another just this side of the near boss. That split line delineates the join between two parts of the casting tool. When the molten aluminium has set hard the central section of the casting tool withdraws first, then the two outer sections move in towards the centre and then withdraw. This allows undercuts to be cast in around the boss area to reduce weight. The cross hatch pattern you can see between the bosses is also typical of a cast piston.

The forged piston on the right has a homogenous smooth internal finish with no split lines and no undercuts. Simples.

[Evoluzione]

Pumaracing said:

What is it you're trying to find out or achieve?

Sadly (and I do mean that as I enjoy a good open debate) you'd have to PM me for that information.
I think it would interest you and you'd probably know the answer or have an angle on it.

Edited by Evoluzione on Monday 14th March 14:33

[sixpistons]

BMW N54, as fitted to 135i, 335i etc had forged pistons.