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As used in the automotive aftermarket world: A part that is machined from a solid block or "billet" of material. As opposed to parts machined from a casting or forging.
You can also Google for billet definitions to find it has a wide range of meanings.
Last edited by Torque1st; Sep 15, 2005 at 02:39 AM.
Like the other guy said. Essentially they machine a solid chunk of metal to the final product. Usually this means a LOT of metal is wasted, But, usually the resulting part is assumed to be stronger.
However, not all parts need to be aircraft quality machining and strength.
Billet almost always means expensive. For engine parts and stressed parts Billet is usually good and cost effective. For things like grills etc, you don't need it.
Actually a forging is much stronger. Billet is probably stronger than cast in most cases but it does waste a LOT of metal and machine time.
He Eric I used to think that way too, but the new aftermarket BBF cranks have me rethinking this, maybe you can explain it. the Billet cranks are first very expensive, and considered top end they cost $2500-3000 and are rated at 1500+hp. the new Forged cranks are looking to run around $1200, and rated at 1200hp so why if the forged are stronger are the billet rated to handle higher HP?
Also the foged rods are rated upto 700hp yet billet rods are rated upto 2000 depending on manufactorer.
Billet camshafts are a different animal completely - they are a basic cam form that can be fed into a lobe grinder and cut any way you want 'em. In other words, they don't have the lobes ground yet. Where you would see cam lobes, you instead see a round journal.
Stock cams have lift added by reducing the base circle, but billets can be cut to greater extremes from the beginning and are used by cam shops to make serious racing cams.
I don't think the material cost between cast and billet is much different. But the labor cost difference between the two is astronomical. On another note, it might be the material cost. But you are actually buying a whole lot of wasted material (chips and shavings). I can also easily imagine that depending on the shape of the component, you could end up with more chips than part.
Think along the lines of that Warner Bros cartoon where a giant redwood tree gets cut down, shipped to the mill and turned down into 1 toothpick.
He Eric I used to think that way too, but the new aftermarket BBF cranks have me rethinking this, maybe you can explain it. the Billet cranks are first very expensive, and considered top end they cost $2500-3000 and are rated at 1500+hp. the new Forged cranks are looking to run around $1200, and rated at 1200hp so why if the forged are stronger are the billet rated to handle higher HP?
Also the foged rods are rated upto 700hp yet billet rods are rated upto 2000 depending on manufactorer.
You nearly lost me there...
I think it must have to do with the materials and techniques involved. Forged always used to be the stronger (at least in cranks) because they are cast in one piece. Billet cranks may have critical flaws in machining, such that they fracture, or they used to.
The state of the art may have advanced is all I can figure.
A "billet" of material is also used to start the forging process. A billet or "chunk" of material is heated then squeezed or hammered into shape. This causes the metal to flow into the required shape which makes for a very strong part. It is then finished to the required dimensions. A forged part is readily identified by the grain structure.
All I know on the subject since I am not a metalurgist, is that the top end engines used in Pro stock are running Billet cranks, and finally someone is coming out with a crank for hte big block fords that is for those that need something inbetween the cast cranks, and the billet pieces (this would include me since in reality my engine puts out more hp than the rated capacity of the crankshaft I am running but most of the guys running the BBF strokers are in this catagory) and that new crank is a forged piece at less than half the cost of a billet piece with a slightly reduced hp rating.
BTW if you check with Jon Kaase on his prostock engines putting out 1600+hp NA at 815cid he doesn't use any forged steel parts it's a billet crank, and billet rods (oops he does use forged pistons but those are alum) and these engines are also turning upwards of 10,000 rpm