Cummins-Ford Swap: Building a Fummins

Die-hard Blue-Oval fans love their Ford trucks—there’s no doubt about that. For decades, Ford F-series trucks have been the best sellers on the market, with hundreds of thousands of diesels being sold. Unfortunately, after 2002, Ford has been dealing with powertrain reliability with the problematic 6.0L powerplant (’03-’07) and the revised, yet still-troubled, 6.4L engine (’08-’10). Although the 6.4L was touted to be a solution to Ford’s diesel engine woes, time has proven that broken regulators, failed turbos, clogged DPF’s, broken rocker arms, and even cracked pistons are still a possibility. In a worst-case scenario, an engine might need a full rebuild, which can run $10,000 to $12,000.

Scott Countryman started Destroked for those looking for a long-term solution to Ford’s engine troubles. Initially working to replace 6.0L engines, Scott saw the writing on the wall with the 6.4L and immediately started working on conversion parts. The engine of choice for most customers is the 6.7L Cummins, which also means folks get a nice displacement bump in addition to much improved reliability. Scott even makes parts to combine the best of the Big Three, as a six-speed Allison transmission is a popular option for those looking to build the “ultimate truck.”

Building a Fummins

“Don’t start with an $800 basket case that has 400,000 miles and every body panel dented,” was the first thing Scott told us. “There are plenty of nice trucks out there with low mileage and engine issues in the neighborhood of $5,000-$8,000,” continued Scott. “We also make conversion parts to keep everything as OEM as possible, so you can retain the factory cooling system, heater, and air-conditioning,” said Scott. “Many people elect to remove the 6.4L engine, but want to keep the 5R110 transmission, so we offer swap parts for that too. For those wanting an Allison, we also offer trick devices like stand-alone transmission controllers and tap shifters that will integrate with the Ford,” noted Scott. “A lot of components that people aren’t sure how to engineer or make, we provide.”

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Brig Pannepacker likes Fummins conversions so much, he owns two of them! While the Harley Edition truck is a 1,000-hp play toy, the workhorse is a F-450 with a 6.7L Cummins swap and Allison transmission—what many might consider the ultimate truck.

“We try to make everything look as OEM as possible,” said Scott. With the cleanliness of the Cummins/Ford engine bay, it’d be hard to believe that it didn’t come with a 6.7L Cummins.

Wiring can be a big challenge with a 6.7L and Allison swap. Fortunately, Scott makes a stand-alone wiring harness for the six-speed Allison 1000 that will work behind any engine combination.

“Simple parts like engine mounts can take some time to fabricate,” said Scott. For those looking to take the first step, 6.4L to 6.7L Cummins swap mounts are available so that the would-be builder can at least locate the engine and transmission.

One of the most essential parts to a Cummins-Ford swap are engine to transmission adapters, which can be acquired to match a Cummins engine to a variety of transmission offerings.

In addition to engine to transmission adapters, transmission to transfer case adapters are available as well, so the factory Ford transfer case can be retained.

While the factory Ford engines can nickel-and-dime owners to death, swapping in a Cummins isn’t exactly a cheap proposition either. Donor engines are $5,000 and up, and transmission cores are usually close to a $1,000. Every once in a while, a dirt-cheap engine and transmission can be found (fire damaged items are a good start), but again, Scott warns “Buy the most complete, best package you can afford for the swap. It’ll save a lot of time (and probably money) in the long run.”

6.7L in, 6.4L Out—Scott’s Swap

“You can recoup a lot of the money by selling the factory Ford parts,” noted Scott. “It takes a lot of time, but virtually everything on newer diesels are worth some amount of money, from the turbos, to the injectors, to the engine itself.” When it comes time to replacing the V-8 with an I-6 however, people invariably run into issues. “There are some parts of the swap that are very hard to fabricate (like transmission adapters), or wiring that is extremely intricate. We offer solutions for whatever the builder can’t design himself,” said Scott.

For many, the Allison 1000 is the transmission of choice when it comes to conversions. Scott told us that its simplicity of design, strength, and computer tuning options make it the perfect automatic to install behind a torque-infused Cummins.

“The goal is to have everything as close to OEM as possible,” said Scott. That means that items like this fan shroud keep the engine’s stock fan working at maximum efficiency.

Ford uses a different pulse configuration to read engine rpm than Cummins, which means the factory tach isn’t plug and play. Fortunately, this handy adapter enables the engine’s computer to talk to the Ford’s harness.

Being Realistic

“A lot of people come into this hoping that they can perform a common-rail Cummins conversion for a couple grand, and that’s simply not the case,” said Scott. “What people can do however, is buy a 6.4L-powered truck for under $10,000, spend about $5,000 to $7,000 on conversion parts (less engine) and end up with a Cummins F-series for under $30,000.” With Cummins’ legendary reliability, and Ford’s robust body and frame construction, a 6.7L I-6 might just be the cure for those suffering the Power Stroke blues. DW

Even with an engine and transmission, it can still be tough to find the bits and pieces to make everything work. Even if an engine comes with an ECM, it still might be missing important pieces like this electronic throttle pedal.

Source:

Destroked

Destroked.com

FREQUENTLY ASKED QUESTIONS

What were the considerations regarding the positioning of the engine and transmission in the chassis?

“Simple parts like engine mounts can take some time to fabricate,” said Scott. For those looking to take the first step, 6.4L to 6.7L Cummins swap mounts are available so that the would-be builder can at least locate the engine and transmission. One of the most essential parts to a Cummins-Ford swap are engine to transmission adapters, which can be acquired to match a Cummins engine to a variety of transmission offerings. In addition to engine to transmission adapters, transmission to transfer case adapters are available as well, so the factory Ford transfer case can be retained.

When considering the positioning of the engine and transmission, several key factors come into play:

Mounting and Clearance: It’s crucial to ensure that the engine and transmission are properly aligned. Using specific engine mounts, like those from 2010 and up Dodge Cummins models, can help in achieving this fit. Precision in measuring and fabricating is vital to ensure all components have the necessary clearance.
Structural Modifications: Sometimes, the chassis may require modifications, such as adjusting the crossmember to accommodate parts like a high-capacity oil pan. These structural changes are necessary to maintain the integrity and functionality of the vehicle.
Component Compatibility: Adapting the Cummins to a Ford chassis involves using adapter plates and clutch kits to ensure seamless integration. This may also involve modifications to the block and bellhousing to fit components such as the starter.
Final Adjustments: Before finalizing the setup, it’s important to confirm all clearances and make any necessary adjustments, such as boxing in cut sections of the chassis for added strength.

These considerations ensure that the engine and transmission are not only securely mounted but also operate efficiently within the chassis framework.

What was the process for final assembly and preparation?

Before final assembly, tasks included painting touch-ups, replacing brake lines with a stainless steel set, and installing new shocks, ensuring everything was ready to fit the body back onto the chassis.

What steps were taken to ensure compatibility between different components?

A crank spacer and a conversion clutch kit were used, and modifications were made to the block and bellhousing to fit the Ford 6.4L Diesel Starter.

How were structural modifications handled?

The structural integrity of the front crossmember was maintained by boxing it after cutting to ensure it accommodated the oil pan.

What is a “Fummins” swap and how is it performed?

Cummins-Ford Swap: Building a Fummins

“Don’t start with an $800 basket case that has 400,000 miles and every body panel dented,” was the first thing Scotttold us. “There are plenty of nice trucks out there with low mileage and engine issues in the neighborhood of $5,000-$8,000,” continued Scott. “We also make conversion parts to keep everything as OEM as possible, so you can retain the factory cooling system, heater, and air-conditioning,” said Scott. “Many people elect to remove the 6.4L engine, but want to keep the 5R110 transmission, so we offer swap parts for that too. For those wanting an Allison, we also offer trick devices like stand-alone transmission controllers and tap shifters that will integrate with the Ford,” noted Scott. “A lot of components that people aren’t sure how to engineer or make, we provide.”

Brig Pannepacker likes Fummins conversions so much, he owns two of them! While the Harley Edition truck is a 1,000-hp play toy, the workhorse is a F-450 with a 6.7L Cummins swap and Allison transmission—what many might consider the ultimate truck.“We try to make everything look as OEM as possible,” said Scott. With the cleanliness of the Cummins/Ford engine bay, it’d be hard to believe that it didn’t come with a 6.7L Cummins.Wiring can be a big challenge with a 6.7L and Allison swap. Fortunately, Scott makes a stand-alone wiring harness for the six-speed Allison 1000 that will work behind any engine combination.“Simple parts like engine mounts can take some time to fabricate,” said Scott. For those looking to take the first step, 6.4L to 6.7L Cummins swap mounts are available so that the would-be builder can at least locate the engine and transmission.One of the most essential parts to a Cummins-Ford swap are engine to transmission adapters, which can be acquired to match a Cummins engine to a variety of transmission offerings.In addition to engine to transmission adapters, transmission to transfer case adapters are available as well, so the factory Ford transfer case can be retained.

Step-by-Step: A Personal Fummins Journey

For those curious about the nitty-gritty of a Fummins swap, let’s dive into a detailed project that showcases the process from start to finish. The journey began with selecting a solid base—a 2000 Ford F250 Superduty with a worn-out 7.3L diesel engine. This truck, affectionately named “Tom,” was chosen for its robust body and manual transmission, making it an ideal candidate for the swap.

Phase 1: Preparation and Installation

Engine Selection: A 24-valve Cummins engine was sourced from a Thomas Built school bus, known for its reliability and long service life. The engine, rated at 250 HP, was set to be upgraded to 350 HP with new injectors.
Disassembly: The donor bus was dismantled, keeping essential components like the wiring harness, air system parts, and battery cables. This stage involved heavy equipment and careful planning.
Condition Assessment: The Cummins engine underwent a thorough inspection, revealing a recently replaced VP44 pump and a well-maintained turbo. The exhaust manifold was resurfaced to prevent leaks.
Installation: The engine was fitted into the Ford, retaining the original ZF6 manual transmission. Key modifications included plumbing the air system for air tools and airbags, and integrating the exhaust brake.
Testing: Extensive test drives ensured the setup was reliable and identified any potential issues to address in the next phase.

Turbo Upgrade: Depending on performance, a larger turbo might be installed if excessive smoke is detected with the upgraded injectors.
Aesthetic and Functional Improvements: Plans included repainting the exterior, upgrading the interior with leather, and fitting custom bumpers for improved durability and style.

6.7L in, 6.4L Out—Scott’s Swap

For many, the Allison 1000 is the transmission of choice when it comes to conversions. Scott told us that its simplicity of design, strength, and computer tuning options make it the perfect automatic to install behind a torque-infused Cummins.“The goal is to have everything as close to OEM as possible,” said Scott. That means that items like this fan shroud keep the engine’s stock fan working at maximum efficiency.Ford uses a different pulse configuration to read engine rpm than Cummins, which means the factory tach isn’t plug and play. Fortunately, this handy adapter enables the engine’s computer to talk to the Ford’s harness.

Being Realistic

Even with an engine and transmission, it can still be tough to find the bits and pieces to make everything work. Even if an engine comes with an ECM, it still might be missing important pieces like this electronic throttle pedal.If you’re looking to retain heat and air conditioning (and who isn’t), Destroked offers conversion lines, as well as engine and transmission lines specifically designed for a 6.4L to 6.7L swap.

What modifications were made to accommodate the Cummins engine in the Ford Superduty chassis?

“Don’t start with an $800 basket case that has 400,000 miles and every body panel dented,” was the first thing Scotttold us. “There are plenty of nice trucks out there with low mileage and engine issues in the neighborhood of $5,000-$8,000,” continued Scott. “We also make conversion parts to keep everything as OEM as possible, so you can retain the factory cooling system, heater, and air-conditioning,” said Scott. “Many people elect to remove the 6.4L engine, but want to keep the 5R110 transmission, so we offer swap parts for that too. For those wanting an Allison, we also offer trick devices like stand-alone transmission controllers and tap shifters that will integrate with the Ford,” noted Scott. “A lot of components that people aren’t sure how to engineer or make, we provide.”

To ensure a seamless integration of the Cummins engine into the Ford Superduty chassis, several key modifications are essential. Starting with the engine mounts, we utilized engine mounts from late model Dodge Cummins trucks. This choice facilitates a more straightforward alignment within the chassis. Additionally, precise measurements led to the crafting of custom plates using CNC plasma technology, ensuring perfect fit and necessary clearances.

Wiring can be a big challenge with a 6.7L and Allison swap. Fortunately, Scott makes a stand-alone wiring harness for the six-speed Allison 1000 that will work behind any engine combination. “Simple parts like engine mounts can take some time to fabricate,” said Scott. For those looking to take the first step, 6.4L to 6.7L Cummins swap mounts are available so that the would-be builder can at least locate the engine and transmission.

Beyond engine positioning, attention was directed towards the transmission. The transmission was repositioned slightly to accommodate a mechanical fan, essential for maintaining optimal cooling. Furthermore, modifications to the front crossmember allowed for a larger oil pan, which ensures better performance under demanding conditions.

One of the most essential parts to a Cummins-Ford swap are engine to transmission adapters, which can be acquired to match a Cummins engine to a variety of transmission offerings. In addition to engine to transmission adapters, transmission to transfer case adapters are available as well, so the factory Ford transfer case can be retained.

Final touches included upgrading the brake lines with a stainless steel set, enhancing durability and safety. To boost engine performance, we locked out the wastegate to maximize boost before securing the turbo with a custom exhaust setup. Once all components were meticulously installed, the body was set back onto the chassis, marking the culmination of a comprehensive and precise conversion process.

How was the Cummins engine connected to the existing transmission?

“One of the most essential parts to a Cummins-Ford swap are engine to transmission adapters, which can be acquired to match a Cummins engine to a variety of transmission offerings. In addition to engine to transmission adapters, transmission to transfer case adapters are available as well, so the factory Ford transfer case can be retained.”

To achieve this connection, several components and adjustments are necessary:

Adapter Plate: A robust steel adapter plate is crucial for aligning the Cummins engine with the transmission.
Crank Spacer and Conversion Clutch Kit: These components ensure smooth power transfer and compatibility between the engine and transmission.
Block and Bellhousing Modifications: Some clearancing of the block and bellhousing is often needed to fit additional parts like the starter.

These steps ensure that the Cummins engine integrates seamlessly with the existing transmission, maintaining the vehicle’s performance and reliability.

How was the starter integrated into the setup?

Modifications were made to accommodate the Ford 6.4L Diesel Starter within the existing configuration.

What modifications were necessary to fit the components?

Modifications involved adjusting both the engine block and the transmission’s bellhousing to ensure compatibility with certain parts.

What specific components were used for the connection?

The setup utilized a steel adapter plate from Wildhorse MFG, along with a crank spacer and a conversion clutch kit sourced from South Bend.