forged vs cast

[literbikedoc]

I think there is a bit of confusion here ... Neither crank is in fact FORGED!!

One is cast Iron (narrow parting line) the other is cast STEEL (wide parting line).

a FORGED crank is manufactured from a BILLET and 100% machined

ie Many of the 327 SBC's in the 50's/60's ran a cast STEEL crank ie the 375hp 'fuellie engine along with some of the higher hp 350's such as the Z28 / LT-1 etc.

FoMoCo also ran a steel crank in some of it's engine such as the 4AMa etc.

so we all know :)

[65ShelbyClone]

@literbikedoc

The only confusion here is on your part.

[literbikedoc]

@65ShelbyClone Clearly you are not experienced in engine building my friend. Moroso / Eagle / Scat / Crower / Iskandarian /GM / FomoCo / Chrysler etc will all tell you the same thing I have!?

'Cast' and 'forged' relate to the method of creating the product from the original base metal NOT the material of composition!!

When you actually see a FORGED crank for yourself you will suddenly realise what I'm saying! I would suggest you check your facts prior to commenting in future .

Regards :)

[65ShelbyClone]

@literbikedoc

I suggest you heed your own advice.

carcraft.com/techarticles/116_­0308_crankshafts_how_to/index.­html

[literbikedoc]

@65ShelbyClone

'Forged' errr ... STEEL crank in the vid has a WIDE parting line vs a std crank's (Nodular cast iron) narrow .. true???

And this is or is not created during the CASTING PROCESS ?????

A FORGED CRANK HAS NO PARTING LINE AS IT IS FORGED FROM A BILLET!!!

End of story dude :)

[65ShelbyClone]

@literbikedoc

You have such a poor grasp on what you're talking about and so little desire to improve that this is where I walk away and let you continue on your merry way in blissful ignorance. Have fun and remember, those people aren't laughing "with" you.

[2jzgtejza80]

@literbikedoc

A forged crank is low-medium carbon steel, a cast crank is cast iron (usually ductile or even better austempered=ADI). The cast iron has excess carbon in the microstructure that acts like a vibration absorber. The steel doesn't have excess carbon and therefore less vibration damping. Some older cranks were cast steel, but they still will not ring like the forged will, not because of excess carbon, but because of the dendritic microstructure. Cast steel cranks are pretty rare today

[literbikedoc]

@2jzgtejza80 Thank you for a factual and somewhat informative take on the subject. How refreshing :)

[2jzgtejza80]

@literbikedoc

You probably doesn't have experience in production of cranks, and you are not in metallurgy, as I am, so I must say, that you and your buddy are wrong. BOTH cranks are made of steel, just left cranks is cast, and right is forged. Cast crank has sharp parting line (cast in sand mold), while forged has wide parting line (high press forged into steel mold). Also surfaces on cast are sharp, and on forged are rounded.

[boobtube56]

The way to tell is forged stays in one piece at 8000 rpm better than cast

[boxer3main]

another way to tell is with hard alloy wheels. they will sing like a bell. True story...

[boobtube56]

Forged cranks also have a wider parting line along with the high pitch ring

[musiclovr2]

put a flywheel on both of them

the ring is not getting deadened from the flywheel

then try this

[elencza]

Thats rirgt MvComeaudoc

[MvComeaudoc]

Thanks.... I have learned something....such a simple test that tell a whole lot!!

[MvComeaudoc]

I assume the one that rings like a bell is the forged crank???