Ad Radar
Diesel Power
Mobile Icon BtnMobile Icon Btn RO
Newsletter

Cummins Diesel Engine Swap - Swap A Cummins Into Anything!

A Complete Cummins Re-Power Resource

Photography by The Diesel Power Staff, The Readers

If you're like us, you've looked at quite a few gasoline- powered rides and thought "that thing would be so much cooler, if it had a diesel in it!" Well, we're here to tell you that it can be done. Diesel engine swaps are becoming more and more common, and while we're starting to see more Power Stroke and Duramax conversions, by far the popular engine of choice is the B-series Cummins.

There are many advantages to swapping an '89 to '98 1/2 5.9L 12-valve Cummins engine into your vehicle. They're everywhere, so they're a cheap engine to buy (especially the '89 to '93 VE-pump versions-although the '94 to '98 1/2 models can produce more power) and parts are easy to find. They're also utterly simple. While newer computer-controlled diesels require multiple computers and a bird's nest of wiring to make them perform properly, the older mechanical engines require two, maybe three wires to make them run. They also have an almost unlimited horsepower potential, a strong aftermarket backing, and a variety of transmission choices.

6BT VS 4BT
Sometimes there are situations where a six-cylinder Cummins 12-valve just won't fit. If you're looking to perform a Cummins swap on a Jeep, small pickup, or a car, the 5.9L engine will probably be too long, too tall, and too heavy. But there is hope. Cummins also made a 3.9L four-cylinder version of the 12-valve called the 4BT. This engine has the advantage of being much shorter, and about 300 pounds lighter than it's bigger brother. The most common applications for these engines were 1-ton bread vans, and box-style delivery trucks.

Fitting The Cummins
OK, so while you're searching for either a four- or six-cylinder Cummins, it's time to think about all the other aspects of getting the diesel engine to fit. The six-cylinder version weighs in at about 1,100 pounds, and is 35x23x31 inches (length x width x height-not including the turbo), while the 3.9L four-cylinder weighs in at about 800 pounds, and is 30x23x31 inches. To simplify matters, we've split this section up into different aspects of the build you'd need to concentrate on.

Engine Issues
Will the engine fit, or will you have to make firewall or frame alterations? Make sure to factor in height as well. Is the engine too heavy for the suspension? Half-ton stuff is probably OK, but if you try to swap a 4BT into a Chevette, you might be in for some trouble.

Transmission Options
You'll be a step ahead if you figure out what transmission you'll be using. Dodge overdrive transmissions such as the 47RH, 47RE, and 48RE are a good choice, but they're heavy. If you're building a smaller vehicle, adapters are available for TH400s, 727 Torqueflites, and Powerglides, as well as manual transmissions. These transmissions are physically smaller, lighter, and have been proven to withstand up to 800 horsepower if built correctly. Keep in mind that your engine will only spin up to 3,000-4,000 rpm, so if you decide do go with a non-overdrive transmission, you may be gearing-limited. Do some research and find out which transmission makes the most sense for you.

The Vehicle
Make sure your swap vehicle is up for the task of handling the torque of a big Cummins. This means making sure your frame won't twist, and your suspension and axles will handle the power without breaking. The last thing you want to do after successfully completing an engine swap is break everything else.

Finishing Details
You're almost there, but there are still a lot of things to think about. Will the vehicle have an intercooler? Will the steering clear? Can a vacuum pump and stock brake system be used, or will the vehicle have to be switched to a power steering pump-driven hydroboost? Is there enough space between the engine and the firewall to mount the exhaust? Remember, the vehicle will also need a large radiator if it is to be used for towing, and you'll need throttle, transmission kickdown, and shutoff linkages to complete the swap. The best place to find all of these items is from a wrecked truck or on the Internet, as buying all the needed parts from your local dealer could nickel-and-dime you to death.

Swap Time
If you've gotten to the point where you know the engine will fit, nothing will break, and you've decided on a transmission, it's time to be realistic about your fabrication skills and motivation level. The last thing you want to do is have a half-finished project sitting in your garage forever. Engine swaps will most likely require some level of fabrication so be prepared to either do it yourself, or have enough money on hand to pay a shop to do some of the work. If you think you've considered everything on this list, then have at it! The sky is the limit on what type of diesel-powered vehicle you can build. DP

Mounting The Engine And Transmission
Many options exist for mounting the engine and transmission. Adam Cornell whipped up his own mounts with a level and some custom fabricating. If you're looking for an easier way out, check out this custom crossmember built by Avalanche Engineering to mount a Cummins into a '73 to '91 Chevy truck. The company also sells a universal crossmember for those who want to get creative. Transmission mounting is also a problem that needs a solution, but thankfully many adapter plates are available to mount the Cummins to any Chevy transmission, Ford E4OD, or even the Pontiac TH400 that is installed in Edward's '41 Suburban.

So You've Decided To Go Electronic
Even though we're focusing on the older mechanical 12-valve Cummins engines that were available in Dodge pickups between 1989 and 1998, '98-1/2 to '02 VP-44 pump-equipped trucks and '03 to '07 common-rail versions are also a good source for Cummins engines if you don't mind dealing with electronics. If you're a wiring kind of guy, it's best to find a wrecked stock version and rob all the necessary computers and wires. If you don't have access to a stock truck, Painless Wiring offers a wiring harness that makes an '03 to '07 common-rail conversion a breeze.

Advanced Alternators
PA Performance out of Boyertown, Pennsylvania, offers a one-wire alternator that doesn't require the Dodge ECU to regulate voltage. Its alternators also provide up to 125 amps at idle (versus 45 for a stock version) so you can run winches, lights, electric fans, or other accessories without worrying about killing your battery.

Swap Resources
To help out with any further questions you may have about Cummins swaps, we've compiled a list of Internet sites where you can do some more digging. Most of these companies are good sources for parts, knowledge, or both. Auto World and FordCummins.com also perform complete conversions.

SOURCES
4BT Swaps
www.4btswaps.com
FordCummins.com
www.FordCummins.com
Auto World
www.autoworldmt.com
PA Performance
704 E. 4th St.
Boyertown
PA  19512
8-77/-471-8010
www.paperformance.com
Avalanche Engineering
www.avalancheengineering.com
Painless Performance
2501 Ludelle St.
Fort Worth
Te  76105
DeStroked
www.destroked.com
  • «
  • |
  • 1
  • |
  • 2
  • |
  • 3
  • |
  • View Full Article
Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!
0 comments