Cast Crank VS Forged Crank

[murphystreeter]

I guess they do make cast steel cranks but I prefer to use a forged as they are stronger. Hypereutectic pistons are junk, they just don't hold up like the forged pistons. Mahle pistons are the best but forged work very well. Sorry, I'm rambling, but this video I believe shows a cast iron crank on top and a steel crank on bottom but I can't tell if it's forged or cast.

[murphystreeter]

The one on top is cast iron...there is a difference. Iron vs. steel (alloy) Iron is not alloy, it's just nodular iron and cast into shape. The steel is much stronger. Nodular iron is soft and will wear over time. (400 ford is the perfect example) The forged crank is much stronger and has a higher pitch. As for rings, cast rings are the best on the market today. Chrome rings lose their tension when they get hot. I must ask, though, do they make a cast steel crank?

[784plb]

its not grain structure, its carbon magonese density in forged producted. its basic physics, has nothing to to with how much grain the metal has. its the chemical process that changes everything. the carbon, magonese combine and joined and in larger molecule groups resulting in a forged product.

[cronos51101]

To some extent, the forged crank is cast, but while the cast crank is simply cast and ground, the forged crank is cast in a continuous process which usually involves metal with far superior chemical properties. After that, the metal is hot worked which improves its mechanical strength, and cold worked into the crank shape. The cold work creates a significant increase in mechanical strength due to the effect it has on the (already superior) grain structure and grain boundaries. Then it's ground.

[4mulas]

Cast = shape by sand molding

Forging = shape by press forces

[1magnit]

They're both cast.

One is cast iron, the other cast steel

[jcadlols]

@1magnit A forging is a casting, it is just heat treated and often a better alloy than cast iron.

[2jzgtejza80]

@jcadlols

Forging and casting are two totally different types of shaping metals.

[2jzgtejza80]

@1magnit

Steel is very hard to cast specially steel alloy for crankshafts, no one do that anymore. There's 3 basic types of making cranks;

1. Cast in sand mold (Ductile Iron, or better Austepered Ductile Iron-known as ADI)

2. Forged with high force press (1500-2500 tons) in metal mold made from Hatfield Steel 12% manganese.

3. Cast in billet, heated, forged billet, and than machined in CNC = (most expensive and the most precise proces)

[frau1234]

opino que ambos estan hechos para propositos diferentes, cierto?

[scl8114515]

well in the way of musical instuments the cast makes a prettier sound

[bestamerica]

'

yes i hear that 2 different sounds of metals,,,

what is different cast VS forged

[tunastrike11]

@bestamerica im not a expert but i think cast is molten metal in a mould and forged is like a solid peice of steel heated and forged into shape by some sort of press that,s what i think it is i know im pretty close or even right.

[bestamerica]

tunastrike11,

'

okay thank explain

[jhoags92]

@tunastrike11 Correct.

[1962polarbear]

Now, I ain't no metallurgist....but back when I was a kid my dad used to take me to the pawn shops when he was looking for tools. I never understood why he dropped them and listened to the sound until a few years ago..... forged vs cast! -and THAT is why those same tools will end up being passed down to my sons...

[gIGoN36]

huahuahuahuauh i can't stop laughing

[pyro8818ak47]

WOW IDIOTS, at the ford plant they take the cranks and throw them on a sheet metal loading tray and a skilled engine tech can tell if there is a crack in the crank from manufacturing just by the sound

[gunforme]

I think the idea here wasn't to show how much force they could take, but simply to show the sound and how one seems to be thicker, stronger, sounding while othe other produces a more weak hollow sound.

[faziljaved]

the one with the dull sound is cast and the one with the crispier more echoing sound is forged here the one coated in oil. forged is a little bit havier but stronger and has longer life.

[jayguy173]

isnt lighter better anyway and everything should be balenced

[luvyouinmouth]

@jayguy173

forged is more about the stregnth, yes lighter is better, but not when you are sacraficing for weaker components. balancing doesnt mean the part can handle the power, but you are correct in taht it should be balanced, but balanced with the paired pistons, rods, rings, and pins.

[ChrisHallett83]

@fungusamogus Yeah I really shouldn't post drunk...

[pimpb0tt]

Where are all the counterweights? Is this a crank from a really big lawnmower?

[piston335]

cast crank and forged crank better good?

[ABUNAI888]

forged = junk

[MrTakosSuprim]

if you thing forged parts are junk, and cast parts are good,

why dont you do the world a favor and go on jet airliner that has cast engine rings

cause we all know that forging metal makes it shit

you dumb fucking retard

[Samqdf]

@MrTakosSuprim tell me what structual force rings are under

[Samqdf]

@ABUNAI888 what the!? care to explain?

[dude9800]

bottom crank actually sounds cracked.

[ChrisHallett83]

Top is cast, bottom is forged.

[shimmyjimmy1994]

top one is forged

[randommagnum]

I'll take both of them, please...and a large Dr. Pepper...

[notoriousleb]

Bottom one sounds tougher..

[mikxr]

i would guess the bell sounding one would be forged but have no idea really.

[MRTOMSK1]

I'll name that tune in 3 !

[2800aaa]

figure it out.

[gixer912]

so which is better

[ripmeup]

You damaged the cranks doing that, you distorted them. Rubbish now for them.

[itdontgo]

You dont think something that is loaded by a piston doing 0 to 100mph and back to 0 again every half a cycle (not to mention the work load) can take a tap with the hammer?

[golbis]

good answer, i dont know if the question was serious, but this kind of tap to a crank is nothing compared to the stress it hold in operation...

[fopeano]

@golbis The two crankshafts are the same dimension/size. the cast one makes a lower pitched sound because the grain structure is more relaxed and there fore complies with applied forced more. The forged crank sounds higher pitched because the grain stucture is tighter and stiffer, causing the same effect as say a guitar string that plays a higher pitch when tightened, and also deflects less against a specific amount of force than if it was looser.

[sjem618]

@itdontgo Offcourse it can!

As long if you don't hit it to hard.

If this would cause it to break then quality testing hasn't been done right.

[AntillRS]

@itdontgo lol. needed to be said.

[lilcow418]

shut up u thick cunt

[musiclovr2]

bull shit hit the fuckers on the same side the cast snout is down,and it is deadening the sound

[Duckyistrippin]

does a tuning fork held upside down make a different sound?

[VayLoc310]

The crank on the bottom sounds like it would be the cast iron crank cuz it's dense, the gold crank on top sounds hollow, the forged steel piece...

[2jzgtejza80]

Right. And also the forged materials you can't brake like ''ripmeup'' think. It's totally new structure of steel.

[VayLoc310]

What did "ripmeup" say?, his comment got so many thumbs down, I can't see his comment lol....

[Duckyistrippin]

@VayLoc310 you know the only difference between casting and forging is the pressure on the mold right? neither are hollow. both solid as a rock. forging lines up the grain structure of the metal, casting leaves disorganized and open ended grains leading to weakness. a dead ring is also a good sign of a cracked crank.

[VayLoc310]

Well for one thing, a cast iron crank is not hollow because it is poured, iron is a soft, heavy metal, if the forged steel crank were solid as a rock, why does it ding like it's hollow?, you can hear the sound go thru the entire casting on the forged steel crank, I could have sworn the forged steel crank was exactly that, forged and cut by the cnc machine

[Duckyistrippin]

@VayLoc310 both casting and forging are "poured" its just how liquid the metal is and how much pressure is put on it that seperates forging and casting. Both produce rough blanks that need final machining. rarely done by a conventional cnc...though everything is automated these days. only the journals and snouts need to be machined, the weights are usually machined a little. flats make it fit, holes r 4 balanc

billet cranks start as solid chunk of steel and are entirely cut from a cnc machine.

[ChrisHallett83]

@Duckyistrippin Wrong way around brother. Casting results in the grains lining up, whereas forged (whether drop forged or hammer forged) 'scatters' the grain alignment, making the granular structure much stronger. See the boundaries between crystals (grins) are the weakest part of the metal, so if you have all these boundaries lining up, it creates a 'path' for cracks to travel along.

[Duckyistrippin]

@ChrisHallett83 no shit? learn something every day!

[ChrisHallett83]

@Duckyistrippin Well actually press forging does cause the grain to flow and the core will line up, but in the case of a crankshaft or high-tensile bolt, this is advantageous, because the grains line up along the body of the part, not across it. Hammer forging is the process that scatters the metals crystals, drop forging to a lesser extent also.

[brendanraymond]

@ChrisHallett83 I`ve never read so much garbage in all my life

you guys are all noobs.

brush up on you`re material science or gtfo

[ChrisHallett83]

@brendanraymond If you're so clever, why not share your infinite wisdom?

[dwhite1939]

The one that rings is the forged one.(the ting sound)

[GSxcsubroto]

which one does the ting sound? and which one does the tuk sound..