Heat forging ls2 bottom end?
04-15-2018, 09:01 PM
#1
Heat forging ls2 bottom end? Ok so I've never heard of it before but a friends of mine knows a mechanic that forges stock parts? Something about heating, coating, reheating, coating, and a final heat? He charges $225 for crank and rods. Does anyone know anything about this and if its actually worth it? Other then this I'm going to be using stock ls2 bottom end with 129k miles. Looking to heads/cam it with this build and boost later. Thanks to anyone who understands what I'm even talking about.
Jason
Jason
04-15-2018, 09:10 PM
#2
TECH Senior Member
Ok so I've never heard of it before but a friends of mine knows a mechanic that forges stock parts? Something about heating, coating, reheating, coating, and a final heat? He charges $225 for crank and rods. Does anyone know anything about this and if its actually worth it? Other then this I'm going to be using stock ls2 bottom end with 129k miles. Looking to heads/cam it with this build and boost later. Thanks to anyone who understands what I'm even talking about.
Jason
Jason
04-15-2018, 09:34 PM
#3
That is NOT forging. It is more of some homegrown heat-treating/tempering(?)/coating process. Forging is the shaping of parts from VERY hot metal with forging dies. Not sure that mechanic even knows what he is doing. If it were an accepted metallurgical process, it would be far more common than what this sounds like.
04-15-2018, 09:56 PM
#4
TECH Senior Member
I would not, unless the whole process was an accepted metal treatment process and not something a machinist cooked up. Besides that, stock components are VERY tough, able to withstand 600HP or more, depending on the situation. Save your money for REAL forged parts, if you are so inclined.
04-15-2018, 10:16 PM
#5
That is NOT forging. It is more of some homegrown heat-treating/tempering(?)/coating process. Forging is the shaping of parts from VERY hot metal with forging dies. Not sure that mechanic even knows what he is doing. If it were an accepted metallurgical process, it would be far more common than what this sounds like.
I would not, unless the whole process was an accepted metal treatment process and not something a machinist cooked up. Besides that, stock components are VERY tough, able to withstand 600HP or more, depending on the situation. Save your money for REAL forged parts, if you are so inclined.
04-16-2018, 01:55 PM
#6
The study of metallurgy is as ancient as the rocks the metals are made from.
To understand what metals are capable of, you first need to understand what they are made of and HOW they are made.
I'll stick with the stock LS2 cast crank and powdered metal rods as an example.
Stock cast nodular iron crankshaft. What this means is that molten alloy is poured into a mold that creates the complete shape of the crankshaft with extra material in the journal areas that will be machined later to a final size.
When the material is poured at a molten state, it then cools and solidifies. The iron then has to go through a series of heat treat cycles at specific temperatures and times to transform the material grains and boundaries (bonds between the grains) to obtain the strength and ductility desired. The recipes of these heat treat cycles have been established for centuries and there's only so much a specific metal is capable of.
"Re-doing" these heat treat cycles will not add any additional strength to the material that wasn't there before. The only thing you can do is use a different "recipe" that may have a higher strength, but at the cost of ductility. Which means, the part will have a higher strength but be more prone to cracking. In a cyclic bending fatigue (think bending a coat hanger) the crankshaft has to be able to withstand these bending forces over time. You want to find the balance between strength and bending. I'm certain the automotive manufacturers have done their homework and have heat treated the crankshaft to the proper condition to have the best balance between the two. No amount of heat cycles is going to change that relationship. The only way to change the relationship between strength and ductility is by changing the material composition itself.
LS2 Powdered Metal Rods
Powdered metal is similar to cast material in that is has a uniform grain structure that does not have a direction. The strength is determined by the composition of the material and the heat treat process it goes through.
Think of metal like this, cast/powdered material is like a granite counter top. The grains are random and uniform. Forged materials are like wood. Forged metal starts of like a piece wood with grain flow in ONE direction. Then when the metal is heated and formed, smashed, bent, etc. the grains follow the direction the metal was formed. By having a grain direction, the metal will have different strengths with the grain flow and against the grain flow.
So, after dipping your toes in the metallurgy water, do you think a heating process of some unknown and unconventional sort is the best thing to spend money on? I'll leave that to you to decide.
To understand what metals are capable of, you first need to understand what they are made of and HOW they are made.
I'll stick with the stock LS2 cast crank and powdered metal rods as an example.
Stock cast nodular iron crankshaft. What this means is that molten alloy is poured into a mold that creates the complete shape of the crankshaft with extra material in the journal areas that will be machined later to a final size.
When the material is poured at a molten state, it then cools and solidifies. The iron then has to go through a series of heat treat cycles at specific temperatures and times to transform the material grains and boundaries (bonds between the grains) to obtain the strength and ductility desired. The recipes of these heat treat cycles have been established for centuries and there's only so much a specific metal is capable of.
"Re-doing" these heat treat cycles will not add any additional strength to the material that wasn't there before. The only thing you can do is use a different "recipe" that may have a higher strength, but at the cost of ductility. Which means, the part will have a higher strength but be more prone to cracking. In a cyclic bending fatigue (think bending a coat hanger) the crankshaft has to be able to withstand these bending forces over time. You want to find the balance between strength and bending. I'm certain the automotive manufacturers have done their homework and have heat treated the crankshaft to the proper condition to have the best balance between the two. No amount of heat cycles is going to change that relationship. The only way to change the relationship between strength and ductility is by changing the material composition itself.
LS2 Powdered Metal Rods
Powdered metal is similar to cast material in that is has a uniform grain structure that does not have a direction. The strength is determined by the composition of the material and the heat treat process it goes through.
Think of metal like this, cast/powdered material is like a granite counter top. The grains are random and uniform. Forged materials are like wood. Forged metal starts of like a piece wood with grain flow in ONE direction. Then when the metal is heated and formed, smashed, bent, etc. the grains follow the direction the metal was formed. By having a grain direction, the metal will have different strengths with the grain flow and against the grain flow.
So, after dipping your toes in the metallurgy water, do you think a heating process of some unknown and unconventional sort is the best thing to spend money on? I'll leave that to you to decide.
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04-17-2018, 08:49 PM
#9
The study of metallurgy is as ancient as the rocks the metals are made from.
To understand what metals are capable of, you first need to understand what they are made of and HOW they are made.
I'll stick with the stock LS2 cast crank and powdered metal rods as an example.
Stock cast nodular iron crankshaft. What this means is that molten alloy is poured into a mold that creates the complete shape of the crankshaft with extra material in the journal areas that will be machined later to a final size.
When the material is poured at a molten state, it then cools and solidifies. The iron then has to go through a series of heat treat cycles at specific temperatures and times to transform the material grains and boundaries (bonds between the grains) to obtain the strength and ductility desired. The recipes of these heat treat cycles have been established for centuries and there's only so much a specific metal is capable of.
"Re-doing" these heat treat cycles will not add any additional strength to the material that wasn't there before. The only thing you can do is use a different "recipe" that may have a higher strength, but at the cost of ductility. Which means, the part will have a higher strength but be more prone to cracking. In a cyclic bending fatigue (think bending a coat hanger) the crankshaft has to be able to withstand these bending forces over time. You want to find the balance between strength and bending. I'm certain the automotive manufacturers have done their homework and have heat treated the crankshaft to the proper condition to have the best balance between the two. No amount of heat cycles is going to change that relationship. The only way to change the relationship between strength and ductility is by changing the material composition itself.
LS2 Powdered Metal Rods
Powdered metal is similar to cast material in that is has a uniform grain structure that does not have a direction. The strength is determined by the composition of the material and the heat treat process it goes through.
Think of metal like this, cast/powdered material is like a granite counter top. The grains are random and uniform. Forged materials are like wood. Forged metal starts of like a piece wood with grain flow in ONE direction. Then when the metal is heated and formed, smashed, bent, etc. the grains follow the direction the metal was formed. By having a grain direction, the metal will have different strengths with the grain flow and against the grain flow.
So, after dipping your toes in the metallurgy water, do you think a heating process of some unknown and unconventional sort is the best thing to spend money on? I'll leave that to you to decide.
To understand what metals are capable of, you first need to understand what they are made of and HOW they are made.
I'll stick with the stock LS2 cast crank and powdered metal rods as an example.
Stock cast nodular iron crankshaft. What this means is that molten alloy is poured into a mold that creates the complete shape of the crankshaft with extra material in the journal areas that will be machined later to a final size.
When the material is poured at a molten state, it then cools and solidifies. The iron then has to go through a series of heat treat cycles at specific temperatures and times to transform the material grains and boundaries (bonds between the grains) to obtain the strength and ductility desired. The recipes of these heat treat cycles have been established for centuries and there's only so much a specific metal is capable of.
"Re-doing" these heat treat cycles will not add any additional strength to the material that wasn't there before. The only thing you can do is use a different "recipe" that may have a higher strength, but at the cost of ductility. Which means, the part will have a higher strength but be more prone to cracking. In a cyclic bending fatigue (think bending a coat hanger) the crankshaft has to be able to withstand these bending forces over time. You want to find the balance between strength and bending. I'm certain the automotive manufacturers have done their homework and have heat treated the crankshaft to the proper condition to have the best balance between the two. No amount of heat cycles is going to change that relationship. The only way to change the relationship between strength and ductility is by changing the material composition itself.
LS2 Powdered Metal Rods
Powdered metal is similar to cast material in that is has a uniform grain structure that does not have a direction. The strength is determined by the composition of the material and the heat treat process it goes through.
Think of metal like this, cast/powdered material is like a granite counter top. The grains are random and uniform. Forged materials are like wood. Forged metal starts of like a piece wood with grain flow in ONE direction. Then when the metal is heated and formed, smashed, bent, etc. the grains follow the direction the metal was formed. By having a grain direction, the metal will have different strengths with the grain flow and against the grain flow.
So, after dipping your toes in the metallurgy water, do you think a heating process of some unknown and unconventional sort is the best thing to spend money on? I'll leave that to you to decide.
No 😳. Stock is fine. Thanks for the information. I think you connected alot of dots for me.