Forged Piston looks cast

[ka67_72]

I purchased a replacement L2256F 030 piston. It's listed as forged, sold as forged, but looks cast. I contacted the seller. They had me send pics and responded, "The L2256F30 is a forged piston. This is evident from the machining on the top." If it is forged it has been shot peened or something. Have any of you seen any of these?

Thanks,
Kevin

[TheSilverBuick]

I've never figured out the clues to look for on a piston to tell if they are forged or cast. I don't "think" it's as cut and dry as cranks and rods because they are aluminum. I've kinda wanted to know because the pistons in my OHC six engines have been replaced and wouldn't it be cool if they magically had forged replacements? Unfortuntately I don't know. =/

That being said, I have cast pistons in my Buick and they are just as shiny on top. I forget what the bottoms look like and don't have any pictures.

[yellomalibu]

Evident by the machining on top?? All pistons are machined on top - and just about everywhere else, so the fact that it's machined on top is evident of nothing but it's a piston.

[ka67_72]

All the other Speed Pro/TRW forged pistons I have, including the broken one with the same part number this is replacing, have distinctive flow lines. The JE's I have, and other high end ones I've seen don't have lines. They're just pretty, but one of them is about as much as a set of Speed Pro's. This one looks like sand. At $34 ea I think I might just buy another one from the other big parts house and compare them.

Thanks,
Kevin

[squirrel]

one clue is that there are no "hidden" places on the inside. The forging process won't make them. Cast pistons usually have recesses inside (like at the top of the pin boss) that indicate that it's cast.

The finish is different from one the older forged pistons, apparently they shot peen them or something before machining

Since there are no mold lines inside the piston, I'd feel pretty confident that it's forged.

edit: I suppose it's possible that it's a chinese sand cast forgery...hard to say without looking at it

[ka67_72]

Evident by the machining on top?? All pistons are machined on top - and just about everywhere else, so the fact that it's machined on top is evident of nothing but it's a piston.

That's what I was thinking. I think the tech guy didn't see the pics and the sales guy doesn't know.

[ka67_72]

one clue is that there are no "hidden" places on the inside. The forging process won't make them. Cast pistons usually have recesses inside (like at the top of the pin boss) that indicate that it's cast.

The finish is different from one the older forged pistons, apparently they shot peen them or something before machining

Since there are no mold lines inside the piston, I'd feel pretty confident that it's forged.

edit: I suppose it's possible that it's a chinese sand cast forgery...hard to say without looking at it

There aren't any undercuts or mold lines. It does have a slight draft to the majority of it.

Thanks

[TC]

edit: I suppose it's possible that it's a chinese sand cast forgery...hard to say without looking at it

I'd have to agree, I've never seen forged pistons with valve pockets like that, and the fact that the rounded part of the valve pockets is wavy and not uniform, other than that the "F" in the part number dictates it as a forged piston.....

[Beagle]

Speed Pro's with an F at the end of the part number and before the oversize number should mean forged... I think they picked that nomenclature up from TRW.

[Loren]

That is an odd looking piston. As Squirrel says, it looks forged by the underside shape but the texture ain't quite right. A forged piston will be relatively smooth as it comes off the polished dies.

[Loren]

I "The L2256F30 is a forged piston. This is evident from the machining on the top."
Thanks,
Kevin

On some more thought...

You know, that is a dumb-ass thing to say, coming from a supplier. They themselves may not actually know what they have.

[ka67_72]

I just ordered one from Jeg's. We'll see if it matches the other guys'.

[Huskinhano]

I'm no expert but my $.02 says cast. Look at the nipple on the underside, too crisp for just as fordged, too much detail. Also the valve reliefs don't look right. They look as though they are cast. A fordged piston IMO would need a lot more machining. Any piston is going to need machining though.

Not saying they're cast for sure but to me, I'd say cast IMO.

[Scott Liggett]

I purchased a replacement L2256F 030 piston. It's listed as forged, sold as forged, but looks cast. I contacted the seller. They had me send pics and responded, "The L2256F30 is a forged piston. This is evident from the machining on the top." If it is forged it has been shot peened or something. Have any of you seen any of these?

Thanks,
Kevin

Those look like my cast pistons in my 383. The bottom shot is looks exactly like sand cast aluminum as well as inside the valve reliefs. Could be just a mis-marked set.

[Barry_R]

They are forged. No question about it at all. But they moved the manufacturing of those pistons to India, and they shot peen them to "improve" the cosmetics...