Is there any huge advantages to forged pistons (toda, endyn) over cast pistons (ctr or balanced jdm itr) on an all motor car? I haven't seen any thing happen to cast pistons that didnt happen to a forged one. Also, I would think that the coating on the honda type r pistons would actually be advantageous compared to a forged piston. Basically, is the extra $600 actually worth it?

 

Stock cast pistons have weak ringlands. Also why not sand off the rough edges and coat your forged pistons?

EDIT: Do you do track events or drag race? If just drag, I'd go with cast. If you road race and your engine has to put up with sustained heat I'd do forged. Either way forged pistons are just extra insurance and I believe in doing things once, the right way.


[Modified by Reid, 2:18 PM 5/8/2002]

 

Forged pistons stand up much better to heat and stress.

 

Anybody consider that forged pistons don't seem to seal very well?

I'm just asking this as a general question.... I have forgotten if high silicone content is what you would be looking at for a moderately tuned "street car"

and low or zero(?) silicone for max durability and less expansion for the ***** to the wall race cars.....


I suppose rings also play a pretty big role in all of this?

 

Just to be clear, don't you mean silicon? Silicon added to aluminum makes an alloy that is stronger than plain aluminum.
<edit>I was mistaken. Silicon added to aluminum lowers the melting point but also makes it more wear resistant. Hence its application to pistons.</edit>

Silicone is the stuff in breast implants and rubber treatment.




[Modified by Gansan, 9:23 PM 5/8/2002]

 

GAHhhhhhh.... didn't proof read my post.... let it be known.....I'm a breast beast.....

 

One thing to add here, a few aftermarket pistons have redesigned oil drainage. This is good for high rpms because as the B18C oil jets spray oil up at the bottom the piston to cool it down, the oil increases the pistons weight. I know that TODA has redesigned oil drainage so the weight of the pistons don't increase at high rpms.

 

First of all, silicone content doesnt apply to strength.
Silicone content will determine expansion rates. Low silicone content will
be stronger but will expand more under heat. This makes them louder
when they are cold.

As far as oil drainage goes, the oil jet thing is irrelevant.
Oil control is for sweeping the oil off of the walls as the piston moves.
Not to drain as the oil is sprayed onto them.

And forged pistons dont seal as well??

 

Well Steve thanks for clearing that up....

I was curious and merely asked based on some motors I have seen which consumed more oil and just happened to use forged pistons....

Now I call your next step and the people I knew probably didn't build their motors correctly.... they probably didn't.... but an inquiring mind had to know....

here's a hammer for you too.....

 

silicone is for breast implants

silicon is derived from sand and added to alloys to limit heat expansion as Stephen stated....and too much of it actually causes the piston to be more brittle (less detonation resistant).

ITR pistons are forged according to Fumiyasu Suga, Type R's assistant chief engineer ( http://integra.vtec.net/carboy.html) but has higher silicon content than the aftermarket pistons. Everyone seems to be eager to jump on the low silicon content forged piston bandwagon like Ross pistons or Arias pistons and put up with the diesel engine-like rattling on cold starts from loose piston to wall clearances....
Cast pistons are wicked brittle...




[Modified by Michael Delaney, 11:44 PM 5/8/2002]

 

looks like he's a breast beast too then....?

 

Low silicone for FI since temps are hotter, and high for NA genrally


I like real ones myself... no silicone for me.

 

Forged pistons are also way lighter than cast ones - which will reduce the mass of the rotating assembly - especially if one uses forged rods as well. This improves the speed at which the motor can rev, and allows the engine to rev higher more safely (assuming it is all balanced properly).

 

So whats the verdict. Are ITR and CTR pistons actually forged or not? They sure look the same as all other B-series pistons from the underside.