For 7.3’s and 6.0’s alike, the fuel system could benefit from an upgrade. One that removes the deadhead issue that plagues each engine. The fix will increase injector life, increase throttle response, and will also quiet down the engine. Let’s discuss exactly what “deadhead” means in regards to the 6.0 and 7.3 Powerstroke engines.

The OE fuel system for both engines sends fuel through a pressure regulator and filter, through fuel galleries in the heads (where the injectors draw their supply from), and it ends there. This type of system is often referred to as a “deadhead” system because the fuel hits a dead end in the head. It’s the same with many common rail systems, not just for our HEUI engines (and it's an issue for common rail engines, too). The issue with a deadhead system is multifaceted. Each comes with its own specific issues, but all affect how the engine runs in a negative way.

High Temperatures. Fuel temperatures can be significantly higher toward the back of the heads due to the lack of flow there. High-temperature fuel comes with less lubricating abilities than cool fuel, so because of that and just the added heat in general, it beats up on the injectors.

Inconsistent Fuel Pressure. Fuel pressures at each injector can fluctuate under heavy load. This means the injectors don’t perform evenly across all 8. Some may supply a little more (or less) fuel than the rest. A problem that becomes very evident in higher performance engines, but one that also does damage to the injectors in any engine, over time.

Air In Fuel. And the biggest issue, air gets trapped in the fuel galleries. Air entrained fuel in the galleries means air in the injectors. This air is one of the bigger contributors to that “cackle” we know so well. Getting rid of that air will quiet down the injector cackle and improve injector efficiency, but more so, it extends their life. Most injectors rely on fuel to slow things down within the injector body. Remove that fuel and parts like the injector nozzle pintle valve speed up beyond what they were designed for, and when they stop, they cause damage. Damage to the point where nozzle cracking becomes possible. While nozzle cracking from this issue is rare, it does happen, and damage does occur whether or not it gets to the point of cracking a nozzle (or other internal injector part).

Removing The Deadhead

Allowing the fuel to flow through the galleries in the heads fixes all the previously mentioned concerns and will also net better throttle response. With fuel able to exit the head, flowing in one end and out the other, trapped air is no longer a concern (allowing for easier and quicker startups especially after running the engine out of fuel or fuel filter changes); pressure can be kept at a more consistent level (assuming the fuel pump is sufficient, an issue usually reserved for engines with larger aftermarket injectors); and fuel temperatures will stabilize throughout simply because it’s not trapped in the back of the heads anymore.

So how do we accomplish this? We create what’s known as a “regulated return” fuel system. A system that regulates fuel pressure on the way out of the heads as opposed to just on the way in. This can be accomplished using our bolt-on Fuel Rail Crossover (FRx) system. The FRx system taps into the fuel return line on the OE fuel bowl with billet adapters and stainless braided lines. The stainless braided lines are then attached to the fuel galleries at the back of each head via existing gallery plugs. And just like that, the engine has a regulated return fuel system allowing fuel to flow through each head before returning to the tank. The engine will now start quicker (assuming no other problems with the engine exist), will run smoother and quieter with increased injector life.  

Check out the Riffraff Diesel Fuel Rail Crossover (FRx) for the 6.0 HERE, and for the 7.3 HERE

***Disclaimer: The information provided on this blog is for informational purposes only. We share our knowledge and experience, but we are not liable for any damages, injuries, or losses that may occur as a result of using this information. Situations are rarely cut and dry in the automotive world. Your situation will likely be somewhat different than what we describe here.  Use your best judgment and always consult a qualified professional for automotive repairs and modifications. Your safety is your responsibility.