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Evidently you got into stroken's stash, step away from the pipe charles. Aftermarket forged rods are a good upgrade from stock but they are not as strong as billett no matter how many funny brownies you eat :pointlaugh:
I got to look at the rods that are/ were in Cales block that came apart. Brian said all the rods were straight and reuseable but they opted not to put them in the new build and went with another set of Hmax forged. Brian said that the forged rods are stronger than the typical billet rods and that is why they use them. Who's billet rods are machined from a block of forged steel, anyones? I would think forged billet would be the strongest if they are available.
 

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I got to look at the rods that are/ were in Cales block that came apart. Brian said all the rods were straight and reuseable but they opted not to put them in the new build and went with another set of Hmax forged. Brian said that the forged rods are stronger than the typical billet rods and that is why they use them. Who's billet rods are machined from a block of forged steel, anyones? I would think forged billet would be the strongest if they are available.
If this were to be done you would not want to start with a forged "block" of steel. You want to start with a forging that closely resembles the rod that you plan to machine it into. The advangages of a forging is that the grain structure of the material flows around the big end and small endof the rod. With a billet rod you cut through the grain structure when you bore the two holes into the material.

Fact of the matter is a standard billet or aftermarket forged rod is already overkill as has been proven already. The extra cost probably isn't worth the effort.
 

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I would think forged billet would be the strongest if they are available.
I've wondered about that too. I don't know if it's correct or not, but I've been told that a forged piece would still be stronger because the grain structure following the shape of the forging. A forged billet piece is usually not forged into a specific shape, but instead into a block and then machined into the shape you want from there. If the billet piece were actually forged into the shape you want and then machined to spec you would think that it would be stronger. Who knows.
On edit: I was 2 minutes late posting, looks like Eric said basically the same thing.

Justin
 

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IMO "billet" and "forged" are contradicting terms and therefore a forged billet is does not make sense.

Billet (to me) means machined of a solid piece of steel or whatever material

Forged means hammered into shape.

Forged will be stronger/harder and billet will be more tolerable to flexing.

Anyway, what advantage is there to forge a shape purposely oversized and have to machine it? Besides raising the cost for no advantage.

Correct me if I am wrong.
 

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The problem with a forged rod also comes from the act of forging. The forging process leaves an inconsistent, rough surface on the rod. This roughness creates a multitude of stress points on the rod. "If you disregard the fasteners, most failures in a connecting rod are generated from some sort of inclusion or stress riser on the surface, "It's like putting a notch in a coat hanger. When you bend it, it is going to break at the notch."




A billet rod is created by literally machining the rod out of a solid chunk of metal. The machining process creates a smooth surface that is (unless there is a problem in the manufacturing process or simply a bad design) free of surface inclusions. By avoiding the forging process altogether you have avoided a weakness, but you haven't been able to take advantage of strength by influencing the grain flow

Not that forged cant be made as strong as your run of the mill billett but billett can be made stronger than forged if the right steel and process is used such as used by your higher end perf manufacturers. Carrillo,crower,and R&R etc.
 

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The problem with a forged rod also comes from the act of forging. The forging process leaves an inconsistent, rough surface on the rod. This roughness creates a multitude of stress points on the rod. "If you disregard the fasteners, most failures in a connecting rod are generated from some sort of inclusion or stress riser on the surface, "It's like putting a notch in a coat hanger. When you bend it, it is going to break at the notch."




A billet rod is created by literally machining the rod out of a solid chunk of metal. The machining process creates a smooth surface that is (unless there is a problem in the manufacturing process or simply a bad design) free of surface inclusions. By avoiding the forging process altogether you have avoided a weakness, but you haven't been able to take advantage of strength by influencing the grain flow

Not that forged cant be made as strong as your run of the mill billett but billett can be made stronger than forged if the right steel and process is used such as used by your higher end perf manufacturers. Carrillo,crower,and R&R etc.
Shot peen a set of Forged rods, which is what the suppliers of high performance forged rods do and you have removed the surface stress factors.

Another thing to consider is that billet rods usually have thicker sections to compensate for being "weaker", which adds to the rotational mass and that can be a negative factor for some engine building goals.

Apples to Apples in terms of design, if the 2 rods in question have all of the same dimensions a forged rod is stronger.
 

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All things being equal (i.e. the physical dimensions of the rod, material type, etc.) a forging will ALWAYS be stronger than a piece made froma a "billet", or from casting.

The forging process changes the internal grain structure of the piece. These "grain lines" follow the shape of the piece, making it strong.

When you cut a rod from a "billet" (a solid block of material), the grain lines in the piece all run parallel to each other. The machining process cuts through these grain lines, thus making a weaker piece (again, all things remaining the same).

Here is an example of grain structure in a forged piece, and how forging vs. machining cuts the grain lines. (Couldn't find a pic of a con-rod, but you get the idea):



The forging process DOES leave a rough suface finish, which can create "stress risers" and cause a surface-stress fracture. Shot-peening and polishing of the rod's outer surface removes most of this, which further increases the strength. Heat treating is last step in creating a hi-strength forged piece.

The problem with forging is that it is expensive, requiring dies, large presses and big heating equipment.

Cutting a piece from a solid billet is relatively inexspensive, particularly with todays modern cad-cam milling machines: throw the piece in and let the machine run it's program while you sit back and read the paper (well, maybe not that simple, lol...but you know...)

Lastly, "forged billet" is kind of a joke, IMO. Yes, you can have a billet block that has been forged instead of the more conventional roll-forming, but the machining of the piece will still cut through the grain structure of the forging, so there is little advantage to this...other than it sounds cool...
 

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Enter what is commonly known as the "fully machined" rod. This process produces the strongest rod (gauging material strength only) by taking the best traits of the forging and billet processes and combining them. A fully machined rod starts out as a large forging (over six pounds in the case of most of Carrillo's rods) and then is machined into its final form much like a billet rod. This produces a rod that has the optimum grain structure of a forging along with the smooth exterior that you find in billet pieces. It's the best of both worlds
 

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Now do the hypermax rods come shot-peened and polished?
 

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so if I got a set of OEM forged rods got them shot peened and cryo treated I would have a rod that would handle my HP goals all day long (500)
They'll handle 500 without doing anything to them with the proper tuning. They still won't be as strong as some of the aftermarket forged rods like Hypermax. They're not as beefy.

Now do the hypermax rods come shot-peened and polished?
Definitely shot peened, I'm sure polished too. They are also cryo'd.

Justin
 

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Discussion Starter · #35 ·
I just fined it hard to stomach the cost of 2600 american

thats a good chunk of change not to mention what the rest of the motor will cost. if your gonna spend that much on rods might as well balance the crank and get a good set of pistons and throw in a main girdle or that sexy swamps bed plate.

even with all those goodies a guy is right up there near 10k
 

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Dont forget that billett is also lighter than forged while still keeping its strength, which is the biggest benefit when building a performance engine. Strength, durability, and lightweight = Expensive :D
My Hypermax rods weigh less than stock, and they should be more than capable of enduring what it would take to rip my block into pieces around them.

I believe the billet options all weigh more than the stock pieces. Some of them considerably more.

You had to have just read that the billet rod will have to be dimensionally larger than the forged rod to produce the same rod strength when equal material is used.
 

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My Hypermax rods weigh less than stock, and they should be more than capable of enduring what it would take to rip my block into pieces around them.

I believe the billet options all weigh more than the stock pieces. Some of them considerably more.

You had to have just read that the billet rod will have to be dimensionally larger than the forged rod to produce the same rod strength when equal material is used.
Billett is dimensionally bigger but lighter than forged considerably, not really rocket science.
 
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