I'm also doing a 1000hp Bottom End Build. The part's I have so far. Colt Cams Stage 3 Cam Shaft. Colt Cams Tappets. Fluidampr and Fluidampr full power kit. Mahle H Series Bearings. Balanced Stock Coated Pistons and 12 Valve Rods, with ARP Bolts. 12M ARP Main Studs. I plan on spinning 4000 rpm. Talking to my engine builder. The 12 valve rods and the stock rods are the same strength. The difference is the stock rods with break and the 12 valve rods will bend. So I plan on upgrading to the Wagler Street Fighter Connecting Rods. And because I will be spinning to 4000 rpm. I will be getting a Beans Diesel Billet Aluminum Gridlock Girdle.
I was in a hurry earlier….
So, Common Rail rods do also bend. I’m trying to think of a time I actually saw a broken rod, I’ve got two rods bent from two engines haha. When the CR came out guys liked to get in a tizzy about rods and how weak the CR rods were and yadda yadda. Which mostly was found to be false. My admittedly limited understanding of metallurgy and grain structures, I would tend to agree that CR rods are more susceptible to breaking. How much more, probably not a lot.
However, (and this isn’t directed at any one person, just general…) there are a ton of variables and factors in every setup. For OP’s setup, he’s got a relatively large set of compounds, which is where I said he could get by with factory rods. A slower spooling setup will naturally move the torque curve up which is easier on rods.
We saw this a lot when the 6.7 came out, and guys would throw on turbos that spoiled and worked well on a 5.9. These spooled like right now (quicker than with a 5.9) and since the engine was getting air it was making an insane amount of low end torque, which beat the hell out of rods and bent them. Move to a bigger, slower spooling turbo and these things made more power, at higher rpm’s, and didn’t bend rods. I seem to recall a large compound setup making like 1400hp on stock rods…but I may be goofy.
So a 5.9 naturally will take more abuse on stock rods than a 6.7 will. A 6.7 will naturally spool bigger turbos better. A larger setup on a 5.9 will have some lag and since the power doesn’t hit so low, the rpm is higher before peak torque and horsepower come in. In order to make horsepower the thing has to spin, this is a function of, well math.
Then we come around to my initial response of how much OP wants to spend. For ultimate reliability and service life at 1000hp, sure rods and maybe even pistons should be done. But that’s what, 5-6k right there? A guy could probably beat on stock rods at 1000 for a couple years but there’s always that possibility of them giving up the ghost.
And this doesn’t even take into account how it’s tuned, which of course plays a major role. We have known entities of fuel and air but the variable there is tuning, who tuned it and how and whether they truly
Know their stuff or take “educated” guesses. I’m too dumb to tune myself 🤣