How many have Broken rods with FI
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From: toronto
How many have Broken rods with FI I was wondering how many guys have broken rods with boost
Either turbo or supercharger
Seems like it doesn't happen too often ?
The reason i ask is i have decided to go with compstar rods over oliver rods The motor is never going to go above 6400rpms
Am i making a bad decision doing this ?
Either turbo or supercharger
Seems like it doesn't happen too often ?
The reason i ask is i have decided to go with compstar rods over oliver rods The motor is never going to go above 6400rpms
Am i making a bad decision doing this ?
not just "it'll be okay..." but WHY it'll be okay I am sure you will be fine.....
Everything I've ever learned says that the strongest loads on your rotating assembly are the inertial loads experieced at TDC (top dead ceneter) and BDC (bottom dead center.) That's the point where your piston stops and maximum acceleration (or negative acceleration) is reached. On an N/A engine those loads are determined strictly by the weight (or mass) of your piston and rod and the engine speed you are running at... I believe the equation is mass X speed(squared) but I'm not sure... but I do know that the load increases exponentially with speed. As long as you stay at 6400 rpm's you are going to be absolutely fine.
On a turbo setup, the only addition you will be adding to the equation is at BDC where the turbo will be forcing air into the cylinder. The valves will be closed by BDC and the increase will be negligible. I really think this incremental increase in the power load is going to be very small caompared to the intertial loads put on the rods at TDC and BDC.
More torque being applied to the piston on the burn cycle in a turbo setup is NOT a material factor. By the time your piston is at BDC, the exhaust valves are open and you are back to the weight (or mass) of your piston times your engine speed.
The most damaging inertial load is when the piston is at the top of the exhaust cycle and there is no compressive load inside the chamber to oppose it. A turbo application gives no potentially damaging loads to this cycle.
So what does all this mean? Engine speed kills!!!!!!!
Everything I've ever learned says that the strongest loads on your rotating assembly are the inertial loads experieced at TDC (top dead ceneter) and BDC (bottom dead center.) That's the point where your piston stops and maximum acceleration (or negative acceleration) is reached. On an N/A engine those loads are determined strictly by the weight (or mass) of your piston and rod and the engine speed you are running at... I believe the equation is mass X speed(squared) but I'm not sure... but I do know that the load increases exponentially with speed. As long as you stay at 6400 rpm's you are going to be absolutely fine.
On a turbo setup, the only addition you will be adding to the equation is at BDC where the turbo will be forcing air into the cylinder. The valves will be closed by BDC and the increase will be negligible. I really think this incremental increase in the power load is going to be very small caompared to the intertial loads put on the rods at TDC and BDC.
More torque being applied to the piston on the burn cycle in a turbo setup is NOT a material factor. By the time your piston is at BDC, the exhaust valves are open and you are back to the weight (or mass) of your piston times your engine speed.
The most damaging inertial load is when the piston is at the top of the exhaust cycle and there is no compressive load inside the chamber to oppose it. A turbo application gives no potentially damaging loads to this cycle.
So what does all this mean? Engine speed kills!!!!!!!
Originally Posted by GMC SKI
I was wondering how many guys have broken rods with boost
Either turbo or supercharger
Seems like it doesn't happen too often ?
The reason i ask is i have decided to go with compstar rods over oliver rods The motor is never going to go above 6400rpms
Am i making a bad decision doing this ?
Either turbo or supercharger
Seems like it doesn't happen too often ?
The reason i ask is i have decided to go with compstar rods over oliver rods The motor is never going to go above 6400rpms
Am i making a bad decision doing this ?
Basically I think if the rods are designed to handle XXXX amount of power, it doesnt matter how you make it.
Have you ever seen a rod advertised for application, like Nitrous rods or Turbo Rods? I havent, but I have seen the pistons like that based off use. Never rods though.
Have you ever seen a rod advertised for application, like Nitrous rods or Turbo Rods? I havent, but I have seen the pistons like that based off use. Never rods though.
Originally Posted by CAT3
Basically I think if the rods are designed to handle XXXX amount of power, it doesnt matter how you make it.
Have you ever seen a rod advertised for application, like Nitrous rods or Turbo Rods? I havent, but I have seen the pistons like that based off use. Never rods though.
Have you ever seen a rod advertised for application, like Nitrous rods or Turbo Rods? I havent, but I have seen the pistons like that based off use. Never rods though.
Andrew
rod bolts and main bearings are the bigger issue I think the bigger factor is the going to be the rod bolts you go with. Let's face it... it's easier to pull rods apart at TDC of the exhaust stroke than it is to push them down so hard on the crank that there is a failure. The rod bolts are what keep everything true (and together) at TDC and you want to make sure you don't skimp out on those, especially at high RPM's. As long as you're going forged you shouldn't have a problem.... powdered metal parts are another story... they are SIGNIFICANTLY weaker.
At BDC when the piston is pushing down on the rod, all of the force is going through the rod to the main bearing and bearing caps. That's what's absorbing the real load.
At TDC, the rod bolts are the weak link. At BDC, the main bearings are the weak link.
At BDC when the piston is pushing down on the rod, all of the force is going through the rod to the main bearing and bearing caps. That's what's absorbing the real load.
At TDC, the rod bolts are the weak link. At BDC, the main bearings are the weak link.
Originally Posted by CAT3
Basically I think if the rods are designed to handle XXXX amount of power, it doesnt matter how you make it.
Have you ever seen a rod advertised for application, like Nitrous rods or Turbo Rods? I havent, but I have seen the pistons like that based off use. Never rods though.
Have you ever seen a rod advertised for application, like Nitrous rods or Turbo Rods? I havent, but I have seen the pistons like that based off use. Never rods though.
