FA20 OEM pistons, are they Forged or Cast ?

[blu_]

Originally Posted by OrbitalEllipses

I don't recall specifics, but I know for a fact that the V7 EJ207 was the last with forged pistons. I just don't recall any engine EXCEPT the EJ207 getting forged internals. Even if the EJ257 or EJ255 have forged rods, they're decent, but nothing to write home about. I'd have to check NASIOC to be certain, but I'm fairly sure I'm right.

HomemadeWRX would know off the top of his head.

Even though this quote is very old. All of the USDM STI's comes with forged rods and and a forged crank.

[NESW20]

my 130hp 5sfe had a forged crank. which is handy when building a stroker 3sgte using said 5sfe crank.

i'm sure the crank on the FA20 is plenty durable.

[PERRIN_Jeff]

Originally Posted by blu_

Even though this quote is very old. All of the USDM STI's comes with forged rods and and a forged crank.

That is correct. The pistons are most likely hyperutectic type, which stronger than normal cast aluminum and expands much less. This is good for emissions, and plenty strong enough for NA engines. This is the same type of pistons used on the STI/WRX.

Realistically, pistons are not going to be a problem until we add boost. Even with 1000RPM more redline, I bet these will do just fine.

[3MI Racing]

I'm with Jeff on this one. Knowing Subaru, who did the engine, they'll be hyperutectic...which looks to be the case with the photo posted up above.

Can't wait to get my engine here so I can start working up the internals.

-Micah
'Homemade WRX'

[Matador]

Originally Posted by NESW20

my 130hp 5sfe had a forged crank. which is handy when building a stroker 3sgte using said 5sfe crank.

i'm sure the crank on the FA20 is plenty durable.

Watch this space

[Tradewind]

Originally Posted by Ishii Motors

Just Aluminum Alloy cast.
Side skirts have a resin coating.
The Top ring groove has a alumite coating.


The crankshaft is forged steel

Ishii

Well done on a very good post, facts and images!

[3MI Racing]

waiting for pistons and heads to land on my bench...driving me nuts.

[3MI Racing]

double post

[serialk11r]

Originally Posted by 3MI Racing

waiting for pistons and heads to land on my bench...driving me nuts.

Do you have the shortblock though? :O Any details? (cough cough rod length)

[Dimman]

Originally Posted by serialk11r

Do you have the shortblock though? :O Any details? (cough cough rod length)

Ishii Motors had rods out in another thread. He may know.

[DragosCarstea]

Hey man I'm so upset right now. I just got myself a turbo kit installed and after a boost leak test drive the mechanic noticed a clicking sound. Took the oil pan out to check what's going on and he found that one of the rods are bent. It's upsetting. 25 day until I come from my deployment and I come home to a brand new broke car...
Gent's if you boosting your car change your rods get some forged rods installed because this sucks. Now the engine has to come out and all that good stuff...

Oh and the car is on a base map so is pushing 300-350hp so nothing crazy

[s2d4]

Originally Posted by DragosCarstea

boost leak test drive

What?

[AVodka14]

I'd say if you are taking the motor out you might as bulk up other components while it's out. Especially pistons.

[Basket Case]

Originally Posted by DragosCarstea

Hey man I'm so upset right now. I just got myself a turbo kit installed and after a boost leak test drive the mechanic noticed a clicking sound. Took the oil pan out to check what's going on and he found that one of the rods are bent. It's upsetting. 25 day until I come from my deployment and I come home to a brand new broke car...
Gent's if you boosting your car change your rods get some forged rods installed because this sucks. Now the engine has to come out and all that good stuff...

Oh and the car is on a base map so is pushing 300-350hp so nothing crazy

Sounds like that's the problem...