Bent rod
09-04-2010, 03:24 PM
#22
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Metal fatigue is cumulative, so bending a rod on the first pull is not surprising on a used stock DE motor, seeing over 300 wtq for the first time. Any other explanation is highly unlikely, imo. You all have too much faith in these wimpy rods!
I would recommend you go with one shop for everything so they can stand behind their work. Getting a mail order block to save a few blocks now may end up costing you a lot more in the long run. Based on several years of forum feedback, I've never heard bad things about Vinny Ten except that he's very busy. If he's willing to work with you to build the motor, I would accept the offer. It's all about your trust in him though. If there was someone in the area you trusted more, I presume you would've gone to them in the first place.
I would recommend you go with one shop for everything so they can stand behind their work. Getting a mail order block to save a few blocks now may end up costing you a lot more in the long run. Based on several years of forum feedback, I've never heard bad things about Vinny Ten except that he's very busy. If he's willing to work with you to build the motor, I would accept the offer. It's all about your trust in him though. If there was someone in the area you trusted more, I presume you would've gone to them in the first place.
Yes, metal fatigue is cumulative...but the engine has 100K miles....not 250K miles. As I've stated before....100K miles is NOTHING for an engine...it's just beginning to wear. The amount of people on these forums that have broken their engines in the 300whp/wtrq range is close to none. Those who have seem to be because of their tunes.
09-04-2010, 06:00 PM
#23
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high mileage does not cause a rod to bend.. A spun bearing WOULD be debateable.. But a bent rod is most likely due to detonation or some other form of a bad circumstance while tuning.
09-04-2010, 08:07 PM
#24
The stock DE rods aren't as wimpy as you state them to be. They aren't exactly GREAT either, but bending one on the very first 300+wtrq pull is just absurd. The stock DE rod is similar to the stock VW 1.8T rod and they can handle 350wtrq for extended periods of time on the stock bottom end...IN A FOUR CYLINDER.
Yes, metal fatigue is cumulative...but the engine has 100K miles....not 250K miles. As I've stated before....100K miles is NOTHING for an engine...it's just beginning to wear. The amount of people on these forums that have broken their engines in the 300whp/wtrq range is close to none. Those who have seem to be because of their tunes.
Yes, metal fatigue is cumulative...but the engine has 100K miles....not 250K miles. As I've stated before....100K miles is NOTHING for an engine...it's just beginning to wear. The amount of people on these forums that have broken their engines in the 300whp/wtrq range is close to none. Those who have seem to be because of their tunes.
This won't be the first time that stock DE rods have bent with FI, and on a first pull. We can just agree to disagree. 
IN MY OPINION, if you're boosted on a stock DE motor, you're on borrowed time, plain and simple. Any other level of understanding is called denial. If you want to find fault elsewhere so that you can rationalize why you're motor isn't going to blow with your "safe" tune, that's all well and good... Have at it, and go right ahead and point fingers at the guy that tuned the fastest VQ car on the planet.
Last edited by rcdash; 09-04-2010 at 08:17 PM.
09-04-2010, 08:59 PM
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I have held my own in my hands and they look pretty pathetic to me! And you want to compare across platforms because the rods LOOK similar to you? This won't be the first time that stock DE rods have bent with FI, and on a first pull. We can just agree to disagree.
IN MY OPINION, if you're boosted on a stock DE motor, you're on borrowed time, plain and simple. Any other level of understanding is called denial. If you want to find fault elsewhere so that you can rationalize why you're motor isn't going to blow with your "safe" tune, that's all well and good... Have at it, and go right ahead and point fingers at the guy that tuned the fastest VQ car on the planet.
This won't be the first time that stock DE rods have bent with FI, and on a first pull. We can just agree to disagree. IN MY OPINION, if you're boosted on a stock DE motor, you're on borrowed time, plain and simple. Any other level of understanding is called denial. If you want to find fault elsewhere so that you can rationalize why you're motor isn't going to blow with your "safe" tune, that's all well and good... Have at it, and go right ahead and point fingers at the guy that tuned the fastest VQ car on the planet.
I also never said he didn't know what he was doing....I said:
I know what happened, the tuner screwed up. It happens and it doesn't even mean he's a bad tuner
I broke an engine once...I blamed it on the engine being weak at first till I realized I screwed up on the calculations so my wideband could work on the gauge I was using.
It happens...we're all only human.
Last edited by GT-ER; 09-04-2010 at 09:05 PM.
09-05-2010, 06:48 AM
#27
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You've held the rods of your DE? I've held rods of over 50 vehicles and have had rockwell hardness tests and shot peening done and what not on all kinds of rods. So what? It's not a pissing contest. OEM rods tend to all be pretty well made material wise...just by looking at them you can normally tell what's good and what's not so good. I'm not defending the VQ rod by saying it's a super strong rod...it's actually pretty weak....but it's not 300+lbft of torque on a single run weak.
I also never said he didn't know what he was doing....I said:
And I stand by it...
I broke an engine once...I blamed it on the engine being weak at first till I realized I screwed up on the calculations so my wideband could work on the gauge I was using. It happens...we're all only human.
I also never said he didn't know what he was doing....I said:
And I stand by it...
I broke an engine once...I blamed it on the engine being weak at first till I realized I screwed up on the calculations so my wideband could work on the gauge I was using.
It happens...we're all only human.If you want to test a rod do a tensile test and even though it may not see much of a twist load do a torsion test and then you can see how the rod stands up, and you should really do a slew of them, maybe about 500-1000 of them to get a good cross section as with the manufacturing of the rods has acceptable flaws that are a result of the process which are probably acceptable to their manufacturing standards for an NA 300 hp car but not for 450hp boosted car, totally different loads seen on the rods.
So one rod may take 500 rwhp while the one next to it might break at 350rwhp or torque, it was made with 250RWHP in mind.
So stop your bs and accept that this kind of thing can happen and an owner going down this path should consider this as a possibility not go into blindly thinking a safe tune will keep them safe.
Last edited by westpak; 09-05-2010 at 06:50 AM.
09-05-2010, 07:02 AM
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Come on, now you are just pulling stuff out of your ****, throwing around terms like hardness and shot penning LOL harness test will tell youpart of the story and shot penning is a process to make a part stornger but has nothing to do with the stock rods unless you do shot peen them and try to use them.
If you want to test a rod do a tensile test and even though it may not see much of a twist load do a torsion test and then you can see how the rod stands up, and you should really do a slew of them, maybe about 500-1000 of them to get a good cross section as with the manufacturing of the rods has acceptable flaws that are a result of the process which are probably acceptable to their manufacturing standards for an NA 300 hp car but not for 450hp boosted car, totally different loads seen on the rods.
So one rod may take 500 rwhp while the one next to it might break at 350rwhp or torque, it was made with 250RWHP in mind.
So stop your bs and accept that this kind of thing can happen and an owner going down this path should consider this as a possibility not go into blindly thinking a safe tune will keep them safe.
If you want to test a rod do a tensile test and even though it may not see much of a twist load do a torsion test and then you can see how the rod stands up, and you should really do a slew of them, maybe about 500-1000 of them to get a good cross section as with the manufacturing of the rods has acceptable flaws that are a result of the process which are probably acceptable to their manufacturing standards for an NA 300 hp car but not for 450hp boosted car, totally different loads seen on the rods.
So one rod may take 500 rwhp while the one next to it might break at 350rwhp or torque, it was made with 250RWHP in mind.
So stop your bs and accept that this kind of thing can happen and an owner going down this path should consider this as a possibility not go into blindly thinking a safe tune will keep them safe.
Nothing is impossible...a bone stock car can throw a rod...a bone stock rod can handle a single 800whp run. Odds point more to the tuner screwing up than a rod bending on a SINGLE 300whp run.
If you believe otherwise, good for you. But I believe people here should start realizing that ALL ( ALL as in 100% of them ) tuners screw up...no matter how good they are and most blame their errors on the engines being weak to save themselves from looking bad. Heck, some won't even know they even made a mistake ( like what happened to me ).
In the end, it doesn't matter...op needs a new engine.
Last edited by GT-ER; 09-05-2010 at 07:36 AM.
09-05-2010, 08:59 AM
#29
Westpak I agree with some of your post except for the quoted statement above. Logically an engineer would not design a part to almost the exact whp said part will be introduced to. An engineer would design a part to withstand higher whp. "If" that's the case "then" you would see failures most DE rods. I quoted the logic statements... We would not be able to boost to almost 400 wtq if they were designed to just 250rwhp.
09-05-2010, 11:43 AM
#31
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Westpak I agree with some of your post except for the quoted statement above. Logically an engineer would not design a part to almost the exact whp said part will be introduced to. An engineer would design a part to withstand higher whp. "If" that's the case "then" you would see failures most DE rods. I quoted the logic statements... We would not be able to boost to almost 400 wtq if they were designed to just 250rwhp.
what is that number what safety factor did they use 50%? 40%... I don't know but trying to find out by boosting the car is not the easiest way, say it is 50% they puts it at 375, what ever the number is we do not know and then you throw in manufacturing defects and it is a crapshoot when you boost the Z and get closer to whatever that number might be.
Basically anyone boosting a Z should be prepared for the possibility of failure and not be surprised when it happens or look to blame anyone else but themselves
Last edited by westpak; 09-05-2010 at 12:28 PM.
09-05-2010, 01:49 PM
#32
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OP....by any chance were you there when they had it on the dyno? If so, what was the deal on your oil??? What about the plugs(new or old). It could be something as simple as OOOOOPS we forgot to add the oil after the TT install. It does happen sometimes.
HEY GUS..
HEY GUS..
Last edited by coachk; 09-05-2010 at 02:09 PM.
09-05-2010, 04:30 PM
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yet i don't have a car to drive
I just don't know what to do.
