The thick 1uz rods are indeed weak
02-01-08, 05:44 AM
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The thick 1uz rods are indeed weak
Hi guys,
I'm reposting this test performed by my firend Arnout in the Netherlands. From left to right, 2jz, 3sgte, 7m, and 1uz. Notice how the 1uz simply shattered.
From Arnout in e-mails about the subject:
"2jz is a very good rod
The 7M was weak but flexible.
The 3s rod was also strong but also because it’s not that lengthy"
Some good info right here.
Thanks Arnout for performing the test.
Eric
I'm reposting this test performed by my firend Arnout in the Netherlands. From left to right, 2jz, 3sgte, 7m, and 1uz. Notice how the 1uz simply shattered.
From Arnout in e-mails about the subject:
"2jz is a very good rod
The 7M was weak but flexible.
The 3s rod was also strong but also because it’s not that lengthy"
Some good info right here.
Thanks Arnout for performing the test.Eric
02-01-08, 06:59 AM
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I think this test is a bit mis-leading.
Torsional test shows the performance of modulus of rigidity.
Tension test shows the tensional strength of modulus of elasticity.
Under normal operation, that kind of torsional load will almost never occur to that amount of magnitude.
Just because the 1uz rod snap off doesn't necessary mean its weaker, it can be more brittle, less elastic, but NOT weaker. Carbide is brittle, it doesn't like to yield under stress, compare carbide to mild steel, the mild steel might elongate 3 to 4% of original length before it failed, but it doesn't mean Carbide is weaker. Carbide's ultimate strength is WAY higher than mild steel.
Personally, that is not a proper way to test the strength of material of connecting rod. Most rod fails at the rod bolts/cap, or the neck of the beam under tensional stress. Or fail under repeatedly compression and tension cycle (Fatigue). I would do a tension test instead.
But then again, assume all 4 rods are made out of the same type of steel, with exact alloy additive, and forged/cast under the same condition; the geometry of the rod will be the only factor and that will determine the winner
Torsional test shows the performance of modulus of rigidity.
Tension test shows the tensional strength of modulus of elasticity.
Under normal operation, that kind of torsional load will almost never occur to that amount of magnitude.
Just because the 1uz rod snap off doesn't necessary mean its weaker, it can be more brittle, less elastic, but NOT weaker. Carbide is brittle, it doesn't like to yield under stress, compare carbide to mild steel, the mild steel might elongate 3 to 4% of original length before it failed, but it doesn't mean Carbide is weaker. Carbide's ultimate strength is WAY higher than mild steel.
Personally, that is not a proper way to test the strength of material of connecting rod. Most rod fails at the rod bolts/cap, or the neck of the beam under tensional stress. Or fail under repeatedly compression and tension cycle (Fatigue). I would do a tension test instead.
But then again, assume all 4 rods are made out of the same type of steel, with exact alloy additive, and forged/cast under the same condition; the geometry of the rod will be the only factor and that will determine the winner
02-01-08, 07:57 AM
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I think this test is a bit mis-leading.
Torsional test shows the performance of modulus of rigidity.
Tension test shows the tensional strength of modulus of elasticity.
Under normal operation, that kind of torsional load will almost never occur to that amount of magnitude.
Just because the 1uz rod snap off doesn't necessary mean its weaker, it can be more brittle, less elastic, but NOT weaker. Carbide is brittle, it doesn't like to yield under stress, compare carbide to mild steel, the mild steel might elongate 3 to 4% of original length before it failed, but it doesn't mean Carbide is weaker. Carbide's ultimate strength is WAY higher than mild steel.
Personally, that is not a proper way to test the strength of material of connecting rod. Most rod fails at the rod bolts/cap, or the neck of the beam under tensional stress. Or fail under repeatedly compression and tension cycle (Fatigue). I would do a tension test instead.
But then again, assume all 4 rods are made out of the same type of steel, with exact alloy additive, and forged/cast under the same condition; the geometry of the rod will be the only factor and that will determine the winner
Torsional test shows the performance of modulus of rigidity.
Tension test shows the tensional strength of modulus of elasticity.
Under normal operation, that kind of torsional load will almost never occur to that amount of magnitude.
Just because the 1uz rod snap off doesn't necessary mean its weaker, it can be more brittle, less elastic, but NOT weaker. Carbide is brittle, it doesn't like to yield under stress, compare carbide to mild steel, the mild steel might elongate 3 to 4% of original length before it failed, but it doesn't mean Carbide is weaker. Carbide's ultimate strength is WAY higher than mild steel.
Personally, that is not a proper way to test the strength of material of connecting rod. Most rod fails at the rod bolts/cap, or the neck of the beam under tensional stress. Or fail under repeatedly compression and tension cycle (Fatigue). I would do a tension test instead.
But then again, assume all 4 rods are made out of the same type of steel, with exact alloy additive, and forged/cast under the same condition; the geometry of the rod will be the only factor and that will determine the winner
That pic is from a 1uz turbo making lass than spectacular HP with a T88 at only 6psi. On the other hand the 2jz stock bottom end just set a new RWHP record of ~1100rwhp. In the 2jz the rods bolts fail along side the rod. It seems to be a fair smattering of both. In the 1uz, the rods give out long before the bolts.
Below is the technician performing the test.
Like I said, the proof is in the pudding. We can talk about it all day long bouncing theories off of each other, but in the end the stock rods stand a chance of punching holes through your block when pushed while the other rods (especially the 2jz) are stout.
Eric
02-01-08, 08:27 AM
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so the 2jz rods are stronger than most any other stock rod? weird, i never heard that before. especially compared to a non turbo engine like the 1uz.
who really thinks that 1uz rods would be able to even come close to comparing? i know some people say this and that, but if i were intersted in boosting my 1uz, i'd eithe rexpect the rods to blow at some point or i'd just buy somthing forged to begin with.
who really thinks that 1uz rods would be able to even come close to comparing? i know some people say this and that, but if i were intersted in boosting my 1uz, i'd eithe rexpect the rods to blow at some point or i'd just buy somthing forged to begin with.
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02-01-08, 08:31 AM
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I see your point, and I'm not trying to debate 1uz rod is as strong or stronger than 2jz rod.
But that method of testing isn't really scientific, and the value of it isn't really in there. Like I said under normal rotational movement, you will almost never see torsional deformation like that, and yet alone to that degree of magnitude. Not to mention get a bigass bar and twist the rod until it fails doesn't really tell much, since the load isn't consistence.
Rating diff. rod in different engine with the level of power production isn't really a "fair" way IMO. hell, just the cylinder configuration already alter the power delivery and overall balance. Inline 6 engine are naturally internal balanced because of the distribution of power stroke and cylinder alignment. Some 90 deg v8 are naturally balance but there is the 2nd and 3rd resonance excitation that hard to suppress.
what I'm saying is, that 1uz might fail because of bad tuning, detonation put abrupt cylinder pressure that really tear things up. but whatever.. interesting stuff regardless
thanks for sharing the pics
But that method of testing isn't really scientific, and the value of it isn't really in there. Like I said under normal rotational movement, you will almost never see torsional deformation like that, and yet alone to that degree of magnitude. Not to mention get a bigass bar and twist the rod until it fails doesn't really tell much, since the load isn't consistence.
Rating diff. rod in different engine with the level of power production isn't really a "fair" way IMO. hell, just the cylinder configuration already alter the power delivery and overall balance. Inline 6 engine are naturally internal balanced because of the distribution of power stroke and cylinder alignment. Some 90 deg v8 are naturally balance but there is the 2nd and 3rd resonance excitation that hard to suppress.
what I'm saying is, that 1uz might fail because of bad tuning, detonation put abrupt cylinder pressure that really tear things up. but whatever.. interesting stuff regardless
thanks for sharing the pics
02-01-08, 08:48 AM
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I agree with gunluvS14, just because something twists and breaks doesn't mean it is necesarily weaker in the application of an engine. I mean if we were talking driveshafts or camshafts, then yeah torsional strength is a big deal...but in engine applications tensile strength is a bigger deal than torsional...rods aren't twisted they are compressed and extended, and the relative speed and thus force of these compressions and extensions is what will break your rod, not some dutch guy sneaking into your engine and twisting your rods....
An example of this brittleness versus strength is if you take a hardened steel (hardened carbon) hammer versus a regular steel hammer. Now the hardened one might snap or shatter wereas the regular one would bend, but the hardened one will be of a greater strength (in one sense of the word). It will have less flex and bend, and while this may result in a catastrophic failure (shattering), it will take a greater force to snap it than it would take to begin bending the other one. So while the failure may seem more dramatic and critical, the point of failure/the strength needed to begin failing/the yield point, will be much greater, in the hardened application.
Know I have no idea about the relative strength of these rods, I haven't done any tests (and if I go serious hp I'm buyign forged rods), but I personally would prefer a rod that can handle a stronger load and then snap at some force x, than some rod that will bend at some lesser force y but not break....put a bent rod into your block and tell me it isn't going to cause serious problems.
Also without a machine applying some sort of tensile strength, or torsional strength for that matter (not some guy twisting a rod in a vice) I'm going to remain skeptical. Not only do we not know at what force the other rods began bending, versus when the 1uz snapped, but we also we don't know how consistently this guy pulled on each of these rods......some guy twisting a piece of metal in a vice and then telling us that one felt harder to break/bend than the others is hardly a definitive answer on relative rod strength in an engine application.
An example of this brittleness versus strength is if you take a hardened steel (hardened carbon) hammer versus a regular steel hammer. Now the hardened one might snap or shatter wereas the regular one would bend, but the hardened one will be of a greater strength (in one sense of the word). It will have less flex and bend, and while this may result in a catastrophic failure (shattering), it will take a greater force to snap it than it would take to begin bending the other one. So while the failure may seem more dramatic and critical, the point of failure/the strength needed to begin failing/the yield point, will be much greater, in the hardened application.
Know I have no idea about the relative strength of these rods, I haven't done any tests (and if I go serious hp I'm buyign forged rods), but I personally would prefer a rod that can handle a stronger load and then snap at some force x, than some rod that will bend at some lesser force y but not break....put a bent rod into your block and tell me it isn't going to cause serious problems.
Also without a machine applying some sort of tensile strength, or torsional strength for that matter (not some guy twisting a rod in a vice) I'm going to remain skeptical. Not only do we not know at what force the other rods began bending, versus when the 1uz snapped, but we also we don't know how consistently this guy pulled on each of these rods......some guy twisting a piece of metal in a vice and then telling us that one felt harder to break/bend than the others is hardly a definitive answer on relative rod strength in an engine application.
02-01-08, 08:49 AM
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The method isn't scientific, but it really wasn't meant to be. It was meant as a quick and dirty test to see what the rods are made of. It's clear that if someone is going to make a fair amount of HP [estimated 500 and above] the stock rods no matter how thick might want to be tossed in favor of forged.
Thanks!
Eric
Thanks!
Eric
Last edited by c0wboy; 02-01-08 at 05:53 PM.
02-01-08, 09:02 AM
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I agree with gunluvS14, just because something twists and breaks doesn't mean it is necesarily weaker in the application of an engine. I mean if we were talking driveshafts or camshafts, then yeah torsional strength is a big deal...but in engine applications tensile strength is a bigger deal than torsional...rods aren't twisted they are compressed and extended, and the relative speed and thus force of these compressions and extensions is what will break your rod, not some dutch guy sneaking into your engine and twisting your rods....
An example of this brittleness versus strength is if you take a hardened steel (hardened carbon) hammer versus a regular steel hammer. Now the hardened one might snap or shatter wereas the regular one would bend, but the hardened one will be of a greater strength (in one sense of the word). It will have less flex and bend, and while this may result in a catastrophic failure (shattering), it will take a greater force to snap it than it would take to begin bending the other one. So while the failure may seem more dramatic and critical, the point of failure/the strength needed to begin failing/the yield point, will be much greater, in the hardened application.
Know I have no idea about the relative strength of these rods, I haven't done any tests (and if I go serious hp I'm buyign forged rods), but I personally would prefer a rod that can handle a stronger load and then snap at some force x, than some rod that will bend at some lesser force y but not break....put a bent rod into your block and tell me it isn't going to cause serious problems.
Also without a machine applying some sort of tensile strength, or torsional strength for that matter (not some guy twisting a rod in a vice) I'm going to remain skeptical. Not only do we not know at what force the other rods began bending, versus when the 1uz snapped, but we also we don't know how consistently this guy pulled on each of these rods......some guy twisting a piece of metal in a vice and then telling us that one felt harder to break/bend than the others is hardly a definitive answer on relative rod strength in an engine application.
An example of this brittleness versus strength is if you take a hardened steel (hardened carbon) hammer versus a regular steel hammer. Now the hardened one might snap or shatter wereas the regular one would bend, but the hardened one will be of a greater strength (in one sense of the word). It will have less flex and bend, and while this may result in a catastrophic failure (shattering), it will take a greater force to snap it than it would take to begin bending the other one. So while the failure may seem more dramatic and critical, the point of failure/the strength needed to begin failing/the yield point, will be much greater, in the hardened application.
Know I have no idea about the relative strength of these rods, I haven't done any tests (and if I go serious hp I'm buyign forged rods), but I personally would prefer a rod that can handle a stronger load and then snap at some force x, than some rod that will bend at some lesser force y but not break....put a bent rod into your block and tell me it isn't going to cause serious problems.
Also without a machine applying some sort of tensile strength, or torsional strength for that matter (not some guy twisting a rod in a vice) I'm going to remain skeptical. Not only do we not know at what force the other rods began bending, versus when the 1uz snapped, but we also we don't know how consistently this guy pulled on each of these rods......some guy twisting a piece of metal in a vice and then telling us that one felt harder to break/bend than the others is hardly a definitive answer on relative rod strength in an engine application.
As for hard vs. strength, in this application you'd not want a hard brittle material since eventually the rod will shatter as pictured above. You'd want something more like the 2jz.
The guy who did the test was Arnout. I know that not a whole lot of people know who Arnout is so just a little background on him; he's a top shelf automotive man in the Netherlands. He builds his own cranks in house, as well as complete motors, projects cars, etc. His knowledge is extensive, and I've never seen him do a project willie nillie. He's not a type of guy to just twist and snap rods just for the sake of it.
Thanks!
Eric
02-01-08, 09:39 AM
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he might know his stuff according to his real life experience but it still doesnt support his findings. i can sit there all day twisting internals of all different types and tell you whether they are weak or strong.
a buddy of mine went had a mchine in college to do tensile tests as well as some other tests. he took an sr20, ka24, and 4g63 rods and actually tested them. the dsm one was the weakest...big surprise, next was ka24 and sr20 was the strongest. and he had data to back up his finding too. i would rather agree with that info then a guy twisting rods.
i can design any part i want in school and run it and see if it fails or not but in the end the professor will always want the data to back up my finding to make sure it wasnt a fluke.
to do testing of this type you need repetition, consistent method, and data. until then this theoretical vs. real-life debate is useless.
i had a vw racing engine throw a carillo h-beam titanium rod while only making 190hp N/A. does that mean that carillo is a bad rod manufacturer. absolutely not. was it a defective rod....yes. btw tuning was not an issue.
a buddy of mine went had a mchine in college to do tensile tests as well as some other tests. he took an sr20, ka24, and 4g63 rods and actually tested them. the dsm one was the weakest...big surprise, next was ka24 and sr20 was the strongest. and he had data to back up his finding too. i would rather agree with that info then a guy twisting rods.
i can design any part i want in school and run it and see if it fails or not but in the end the professor will always want the data to back up my finding to make sure it wasnt a fluke.
to do testing of this type you need repetition, consistent method, and data. until then this theoretical vs. real-life debate is useless.
i had a vw racing engine throw a carillo h-beam titanium rod while only making 190hp N/A. does that mean that carillo is a bad rod manufacturer. absolutely not. was it a defective rod....yes. btw tuning was not an issue.
02-01-08, 09:52 AM
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Well, yeah man. I mean it did. His finding supported fully the fact that the rod came apart. There's not much more to that. Arnout didn't twist all day, but he took a little time out to twist some sample rods and above are the finding. It's pretty much a take it or leave it scenario, but to be honest, the proof is in the way the rod perform in the engine. So far it seems to be hand in hand.
i can design any part i want in school and run it and see if it fails or not but in the end the professor will always want the data to back up my finding to make sure it wasnt a fluke.
to do testing of this type you need repetition, consistent method, and data. until then this theoretical vs. real-life debate is useless.
to do testing of this type you need repetition, consistent method, and data. until then this theoretical vs. real-life debate is useless.
In the end though, the rods go in the engine, the engine is boosted and the rods failed. That's flat out. If it was a fluke, I suppose the resuts would have been different. Everybodys got their own way of testing I guess, but in the end, everyones rods do the same job. Thanks!
Eric
02-01-08, 09:53 AM
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