lionbull Posted June 6, 2013 Report Share Posted June 6, 2013 So my tuner asked me if i got rods in the motor. I asked my do you ask me if i got rods and not pistons. He said the rods are more important as long as there is no detonation. A stock(non forged) turbo piston will handle tons of abuse. So I let him know my stock rods are tough stuff. Now before we start debating about the g54b needs forged pistons for 15psi LOL, I said generally speaking, in the thread title. We have some 11 second maximas on the street with stock blocks. When one blows its always the rods and never the pistons... Link to comment Share on other sites More sharing options...
polarisman14 Posted June 6, 2013 Report Share Posted June 6, 2013 To be fair, I believe our rods are forged from the factory, and the crank is nitrided. I too have heard that the pistons are rarely the issue provided you don't have detonation issues. That assumes you have a very competent tuner, though, and it is difficult to get the tune bang-on without some issues here or there. That, and if you are going on the ragged edge, running on the leaner side of things and putting some timing in it, your chances of detonation go up quite a bit, as do they if you live in a hotter climate. I'm sure elevation has a significant effect too. Link to comment Share on other sites More sharing options...
Komeuppance Posted June 6, 2013 Report Share Posted June 6, 2013 Stock pistons are strong, but like any non forged easy to blow ring lands on if your tune isn't good enough. You can blow ring lands easily with a bigger turbo on the stock ECU too. The tune/upkeep is what is most important in these engines, they're built reliably strong stock... but when you get an owner who isn't up to the task, they'll go kaboom. Then the owner blames the motor instead of themselves. -Robert Link to comment Share on other sites More sharing options...
Scotty Dont Posted June 6, 2013 Report Share Posted June 6, 2013 Our rods are not forged but they are pretty stout and will not be the weak link with stock pistons. Link to comment Share on other sites More sharing options...
jszucs Posted June 6, 2013 Report Share Posted June 6, 2013 If your going to push them, it makes sence to have them fully preped when your taking it all apart to have the motor ballenced anyways. Link to comment Share on other sites More sharing options...
patra_is_here Posted June 6, 2013 Report Share Posted June 6, 2013 I think the OP is asking a GENERAL question (not specific to the g54b right?) what fails first when making power? pistons or rods rods. Link to comment Share on other sites More sharing options...
Funky Phil Posted June 6, 2013 Report Share Posted June 6, 2013 rod "related" failures are common Link to comment Share on other sites More sharing options...
jszucs Posted June 6, 2013 Report Share Posted June 6, 2013 ^ yeah I think that is more it. I would say in most cases the rods are fine, it's the "related" that causes a rod problem. Link to comment Share on other sites More sharing options...
psu_Crash Posted June 6, 2013 Report Share Posted June 6, 2013 Spinning a rod bearing seems to be somewhat common but I've only even seen a couple bent/broken G54B rods and even then I don't believe the rod was to blame.If you are worried about the rods then stress relieve, shot peen, recondition the big end and balance them. No need for high end forged rods in my opinion. Link to comment Share on other sites More sharing options...
AUSSIEOLDIE Posted June 6, 2013 Report Share Posted June 6, 2013 Would check the prices for Eagle forged rods against the cost of fully preping stock rods. Link to comment Share on other sites More sharing options...
Funky Phil Posted June 6, 2013 Report Share Posted June 6, 2013 ive seen a handful of "stock" rods eclipse the 500whp mark Link to comment Share on other sites More sharing options...
screemin eagle Posted June 6, 2013 Report Share Posted June 6, 2013 ive seen a handful of "stock" rods eclipse the 500whp markDing ding!!!!!!Evo's do it all the time too.I wouldn't compare a Nissan to a Mitsu in any way shape or form. They have definitely always been below par IMHO. Link to comment Share on other sites More sharing options...
Komeuppance Posted June 7, 2013 Report Share Posted June 7, 2013 Yep, Nissan/Datsun engineers most of their engines to a lower strength level vs Mitsubishi. -Robert Link to comment Share on other sites More sharing options...
jszucs Posted June 7, 2013 Report Share Posted June 7, 2013 ive seen a handful of "stock" rods eclipse the 500whp mark Don't fotget though most of those are not also with maxed out torq numbers or torq numbers higher then HP numbers. So they are not a long stroke or a large piston. They are also fairly light weight so not as much stress on rods. Link to comment Share on other sites More sharing options...
TopDawg_43 Posted June 7, 2013 Report Share Posted June 7, 2013 It's hard to say when a rod falls, IMO. The only time I've seen a rod bend is when a engine has sucked a bunch of water through the intake. Whan an engine throws a rod, is that rod failure, pin failure, or rod bolt failure? But I have seen pistion failure. Weather it be the ring lands or the piston cracks. So, in my opinion, the piston will fail before the rod. I might would argue that rod bolts must be upgraded before the rod. Link to comment Share on other sites More sharing options...
jszucs Posted June 7, 2013 Report Share Posted June 7, 2013 That's why I agree "rod related" fails I call a rod failure when you litterly break a rod and that is rare. As for your hydro lock scenerio I have seen that with gas blown in also. But that was injector fail .... actuly FPR fail and presure went to the moon and just blew them open. Was also a drag only car and an idiot more is better owner. Link to comment Share on other sites More sharing options...
lionbull Posted June 7, 2013 Author Report Share Posted June 7, 2013 rod caps and the rod bolts take the brunt of the stress,assuming the piston is strong enough to hold the wrist pin and the tune is good...your thoughts? Link to comment Share on other sites More sharing options...
Funky Phil Posted June 7, 2013 Report Share Posted June 7, 2013 Don't fotget though most of those are not also with maxed out torq numbers or torq numbers higher then HP numbers. So they are not a long stroke or a large piston. They are also fairly light weight so not as much stress on rods. What are you talking about? Load is Load. Are you trying to turn this into another HP vs TQ debate? Link to comment Share on other sites More sharing options...
lionbull Posted June 7, 2013 Author Report Share Posted June 7, 2013 So, in my opinion, the piston will fail before the rod. I might would argue that rod bolts must be upgraded before the rod. I agree, especially with our cars. If we do rod bolts coupled with our tough rods the only thing that could fail is the piston. I guess for a mild build we don't need forged slugs. Our stock pistons are not weak after all. I can make a case for forged because they are lighter, stronger and come with better wrist pins. Those get ripped from a stock piston if pushed too hard. So what is a mild build?your thoughts? Link to comment Share on other sites More sharing options...
jszucs Posted June 7, 2013 Report Share Posted June 7, 2013 What are you talking about? Load is Load. Are you trying to turn this into another HP vs TQ debate? No there is a major difrence betwen a motor with a short stroke, small, light weight piston and the forces that produces when it has to change direction VS a car with a very short stroke and smaller light weight piston. Link to comment Share on other sites More sharing options...
lionbull Posted June 7, 2013 Author Report Share Posted June 7, 2013 No there is a major difrence betwen a motor with a short stroke, small, light weight piston and the forces that produces when it has to change direction VS a car with a very short stroke and smaller light weight piston. when you say that "there is a major difrence betwen" you MUST say the difference in order to make your point, if there is any... Link to comment Share on other sites More sharing options...
jszucs Posted June 7, 2013 Report Share Posted June 7, 2013 (edited) when you say that "there is a major difrence betwen" you MUST say the difference in order to make your point, if there is any... Isn't that what I did. there is a major difrence betwen a motor with a short stroke, small, light weight piston and the forces that produces when it has to change direction VS a car with a very short stroke and smaller light weight piston. Are you asking me to break it down like a piston that weights 10 oz and moves 6" is going to have allot more force applied to all related parts (including rods) when it changes direction then a piston that weights 5 oz and moves 3" when it changes direction. There are also other implications to the rods if it's a inline, a V or horizontaly opposed too. I guess a W too. Edited June 7, 2013 by jszucs Link to comment Share on other sites More sharing options...
patra_is_here Posted June 7, 2013 Report Share Posted June 7, 2013 =( The TQ is the instantaneous force generated by the force of the explosion pushing down on the piston. then there is another force when the piston moves back UP to TDC and stops momentarily. yes a 10oz piston and a 5oz piston are going to produce different loads on the rods, but not how you describe. hell, the 5oz piston will allow for a FASTER acceleration of the piston, which means a greater rate of change, which is going to produce higher loads. you're simplifying it to just this premise of the 'mass' of the components, when that's not the only loads they experience. you're completely overlook the instantaneous loads generated by combustion (i say instantaneous because TQ has no value of time, but we could just let the time approach 0 and change the units and do some differential equations but that's not really going to help prove it, because it's still going to give us a value with no time variable) Link to comment Share on other sites More sharing options...
Funky Phil Posted June 7, 2013 Report Share Posted June 7, 2013 No there is a major difrence betwen a motor with a short stroke, small, light weight piston and the forces that produces when it has to change direction VS a car with a very short stroke and smaller light weight piston. oh my goodness. And when did I bring up a short stroke setup? What G54B has a short stroke?If youve had much experience with making decent power with a G54B you wouldnt keep bringing this up. Your piston speed/redline scenario has nothing to do with the numbers an engine will put out. If anything it is a small piece of the puzzle that becomes load. Link to comment Share on other sites More sharing options...
Funky Phil Posted June 7, 2013 Report Share Posted June 7, 2013 and nothing you guys are talking about applies to the question. Link to comment Share on other sites More sharing options...
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