True limits of gen 4 rods hp wise
TECH Apprentice
Joined: Apr 2012
Posts: 333
Likes: 4
From: New Zealand
I was told 650rwhp is the safe limit if you lean on it often or for long periods... I'm down 10-15psi on 1 cylinder after 1 or 2 too many backfire pops. I ran at 663rw so wonder if the safer limit might be 600rw tops. I think mainly street plus the odd track pass could get away with more, but I do road course hot laps and week long closed road events so that's pretty tough on a stock motor - lots of heat issues to work through. I'm going to forge and add oil coolers asap.
TECH Fanatic
Joined: Oct 2014
Posts: 1,220
Likes: 179
From: Virginia
Here's some good info on the subject. Piston is the weakest spot. They break around 1000 HP. Cranks and rods can take more, but not sure how much. If you are swapping pistons, why not do the rods too? Worth the extra $$$. Texas Speed has some good stuff, always been happy dealing with them.
Thread Starter
Teching In
Joined: Feb 2019
Posts: 19
Likes: 0
Here's some good info on the subject. Piston is the weakest spot. They break around 1000 HP. Cranks and rods can take more, but not sure how much. If you are swapping pistons, why not do the rods too? Worth the extra $$$. Texas Speed has some good stuff, always been happy dealing with them.
https://www.youtube.com/watch?v=_g-4d3VKWH0
https://www.youtube.com/watch?v=_g-4d3VKWH0
hard to put a hp level on the rods as the tune has everything to do with if it lives or not. on that same note the best pistons and rods you can buy will not live if the tune is bad and it detonates. . there are plenty of these engines in the 8s with stock lower ends. and they live a long time. I have run a few with hp in the mid 700s at the wheel. and they live for years . if you build a gen 4 engine get the bearing clearances right and the ring gaps opened up a bit and the tune is on you will have an engine that in my mind is hard to kill. but the supporting parts need to be there. it needs good fuel and supply a good oil pan and a good tune. I have not seen one fail that did not have a fuel system or tune issue.
Thread Starter
Teching In
Joined: Feb 2019
Posts: 19
Likes: 0
hard to put a hp level on the rods as the tune has everything to do with if it lives or not. on that same note the best pistons and rods you can buy will not live if the tune is bad and it detonates. . there are plenty of these engines in the 8s with stock lower ends. and they live a long time. I have run a few with hp in the mid 700s at the wheel. and they live for years . if you build a gen 4 engine get the bearing clearances right and the ring gaps opened up a bit and the tune is on you will have an engine that in my mind is hard to kill. but the supporting parts need to be there. it needs good fuel and supply a good oil pan and a good tune. I have not seen one fail that did not have a fuel system or tune issue.
http://www.radiumauto.com/Fuel-Hange...-FD-P1390.aspx
I am aiming for 800 whp, but not constant. Just when I want the extra power. I will be set up on an ebc so i can switch with ease. And I trust my tuner. I just dont want to build a decent motor and the weakest link be the rods, ya know? I was mostly curious more than anything..
Trending Topics
You don't need Forged pistons. Gen 4 rods and pistons are good for 1000 wheel with a tuner that knows how to keep them alive. I'd spend the money on forged pistons else where. If it's on e85 with a GOOOD tune you're set for 800 wheel reliably
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0
Brett Foote
Thread Starter
Teching In
Joined: Feb 2019
Posts: 19
Likes: 0
The only reason I went for a forged slug is because I had to bore my cylinders. They were pitted. Thats why I found a set of forged pistons that could be used with the .945 wrist pin of the gen 4 rods.
Here's some good info on the subject. Piston is the weakest spot. They break around 1000 HP. Cranks and rods can take more, but not sure how much. If you are swapping pistons, why not do the rods too? Worth the extra $$$. Texas Speed has some good stuff, always been happy dealing with them.
https://www.youtube.com/watch?v=_g-4d3VKWH0
https://www.youtube.com/watch?v=_g-4d3VKWH0
hard to put a hp level on the rods as the tune has everything to do with if it lives or not. on that same note the best pistons and rods you can buy will not live if the tune is bad and it detonates. . there are plenty of these engines in the 8s with stock lower ends. and they live a long time. I have run a few with hp in the mid 700s at the wheel. and they live for years . if you build a gen 4 engine get the bearing clearances right and the ring gaps opened up a bit and the tune is on you will have an engine that in my mind is hard to kill. but the supporting parts need to be there. it needs good fuel and supply a good oil pan and a good tune. I have not seen one fail that did not have a fuel system or tune issue.
Yup, throw boost at them and not timing and it'll reward you for a long time.
a lot of the ones I have been on the dyno with lately I have been getting 720 to 780 hp at the wheels with 15 degrees timing and 20 ish # boost on e85. they live a good long life at that level with afr in the 11.7 range on the gas scale.
On The Tree
Joined: Jul 2017
Posts: 193
Likes: 2
Gen 4 pistons and rods are both strong enough to sustain 1400+hp for a 1/4 mile blast at a time. Jon was putting 100+ passes on his running 170-178mph through the stripe shifting at 8200-8400. The only time he has bent them in the last 300ish passes doing this is when he lifts the heads. He believes he is simply "hydroing" them when the water starts entering the chambers.
Thread Starter
Teching In
Joined: Feb 2019
Posts: 19
Likes: 0
Gen 4 pistons and rods are both strong enough to sustain 1400+hp for a 1/4 mile blast at a time. Jon was putting 100+ passes on his running 170-178mph through the stripe shifting at 8200-8400. The only time he has bent them in the last 300ish passes doing this is when he lifts the heads. He believes he is simply "hydroing" them when the water starts entering the chambers.
On a side note, what is everbodys opinion on oil squirters by Get M' Garage? Good to have for cooling, or just go without them? Its not uncommon in the Honda world (where I'm from lol) to block them off at higher hp.
