Upgrading Your 6. 7 Cummins Valve Springs and Pushrods
In case you're pushing even more boost than stock, upgrading your six. 7 cummins valve springs and pushrods is one associated with those "boring" mods that actually retains your engine through exploding when issues get rowdy. We all like the sound associated with a big turbo spooling up and the feeling of this extra torque pinning us to the particular seat, but those performance gains come with a hidden cost. The inner components that had been perfectly fine to get a 350-horsepower daily driver start to battle when you double that will output.
Most guys begin with a tuner, maybe an consumption, and a bigger wear out. Then comes the particular bigger turbo and higher-flow injectors. Before you know it, you're pushing fifty or 60 pounds of boost, and that's exactly exactly where the factory valvetrain starts to complain. It's not that Cummins built a fragile engine—far from it—but they built it to satisfy a specific set of guidelines from the stock. High-performance diesel builds usually blow correct past those parameters.
Why Share Parts Fail Under Pressure
Let's talk about why you even need in order to wreak havoc on your valvetrain in the first place. The 6. 7 Cummins is definitely a workhorse, yet the factory valve springs are remarkably soft. They're created for efficiency and longevity at stock RPM ranges and stock boost levels. When you start throwing 40+ POUND-FORCE PER SQUARE INCH of boost on the engine, that air flow pressure is literally wanting to hold the particular intake valves open.
In case your valve springs don't have enough "seat pressure" (the force holding the particular valve closed), the boost pressure may overcome the spring. This leads to something called valve float. When the valve doesn't close completely or even bounces from the seat, you lose compression, you lose strength, and in the particular worst-case scenario, your own piston decides in order to have a very violent meeting along with your valve. That's a bad time for everyone included.
Then presently there are the pushrods. If you've ever held a stock 6. 7 Cummins pushrod in your hand, you know they aren't exactly massive. These people look more like heavy-duty drinking straws than high-performance engine components. When a person install stiffer valve springs to battle off valve float, you're putting far more stress on all those pushrods. Under higher RPM or high load, those thin factory rods can actually flex or bend. When they contract, your valve time goes out the windowpane, and your engine starts running like a bag of hammers.
The Magic of Weightier Valve Springs
Upgrading your springs is mostly regarding control. You would like to make sure that no matter how much boost you're producing or how high you're revving, that valve follows the camshaft profile specifically. Most aftermarket 6. 7 cummins valve springs and pushrods kits offer a significant jump in chair pressure.
Stock springs usually sit around 70-80 lbs of seat pressure. Upgrading to a "103-lb" or even "110-lb" spring is a very common move with regard to street-strip trucks. It offers enough force to maintain the valves sitting even when the manifold pressure is definitely through the roof.
The elegance of these upgraded springs is that they don't simply protect the motor; they can even make it more efficient. When the valves close cleanly and stay shut, you get better combustion and even more consistent power delivery. You may notice typically the engine feels a bit "crisper" from high RPMs because the valvetrain isn't striving to keep up with the demands of the camshaft.
Why Beefier Pushrods Are the No-Brainer
In the event that you're doing the springs, you absolutely have got to do the particular pushrods. It's almost a rule of thumb in the Cummins world. Due to the fact the new springs are much more difficult to compress, the force required to open the valve increases. Your manufacturing plant pushrods were never ever designed to push against that kind associated with resistance.
High-performance pushrods are often produced from seamless crmo steel tubing and have got much thicker walls than the share units. They don't flex. When the lifter moves upward, every bit of the motion is moved directly to the rocker arm and the valve. This particular "rigidity" is key to maintaining your engine's timing and ensuring you're obtaining the full lift out of your own camshaft. Plus, they're just way harder to break. If you ever over-rev the engine or have a minor timing accident, a beefy pushrod might be the between a basic fix and a total rebuild.
Choosing the Ideal Setup for Your Build
Not everyone needs the particular craziest triple-spring setup and 7/16-inch heavy pushrods. If you're just managing a "hot" street tune and maybe a slightly larger drop-in turbo, a set of 103-lb springs and heavy-duty 3/8-inch pushrods is usually plenty. It's a great "insurance policy" that will gives you serenity of mind without being overkill.
However, if you're building a devoted drag truck or a sled puller, you're going to desire to go larger. Once you enter the realm associated with 800+ horsepower and 4, 000+ REVOLTION PER MINUTE, the demands within the valvetrain are insane. At that point, you're taking a look at significantly higher seat stresses and pushrods that will look like they will belong in the piece of weighty construction equipment.
The key would be to match the parts to your goals. There's simply no point in putting in springs which are so stiff these people cause unnecessary put on on your flat-tappet cam if you're only making 450 horsepower. But with regard to most of us who can't keep well enough alone, a moderate upgrade is the sweet spot.
Tips for a Smooth Installation
Swapping out six. 7 cummins valve springs and pushrods isn't necessarily "hard, " but it is tedious. You're doing work in a limited space, especially close to the back of the head by the firewall (cylinders 5 and 6 are always a blast, right? ).
One of the biggest tips is usually to make sure you possess the right tool for compressing the springs while the head continues to be on the motor. There are specific bridges made for the Cummins head which make this particular job ten periods easier. Also, a person have to create sure you don't drop a valve into the canister. Most guys make use of the "top useless center" method—rotating the particular engine therefore the piston for the cylinder you're working upon are at the pretty top. This way, if the valve slips, it only drops a fraction of the inch and strikes the piston rather than disappearing into the particular abyss.
While you have the rocker box off, it's also time for you to check out your valve lash. Since you're already in there messing with all the pushrods, you might as well obtain everything dialed within to factory specs (or whatever your aftermarket cam manufacturer recommends). A small extra time spent here will make the particular truck run very much smoother and quieter once you fire it back upward.
Is It Worth the Effort?
At the end of the time, spending money on 6. 7 cummins valve springs and pushrods isn't as "sexy" since buying a shiny fresh turbo or a fancy manifold. A person can't see them once they're set up, and they don't really change the wear out note. However they are foundational.
Think of it such as building a home. You can place the nicest house and windows upon it, but in the event that the foundation is usually weak, the whole thing is ultimately likely to have difficulties. Upgrading your valvetrain is building that foundation. It allows you to use the power you've currently built more properly and opens the door for even more upgrades down the road.
If you're planning on keeping your vehicle for a long time and you like to utilize the right foot, this is an upgrade you won't regret. It's about reliability, performance, and that wonderful feeling of knowing your engine isn't likely to turn itself in to a pile of costly scrap metal next time you decide in order to pass someone upon a steep grade. It's one of those modifications that will just makes sense once you stop looking at the dyno numbers and start looking at just how these engines in fact work under pressure.