Welcome to Top Tech Questions. Oftentimes, readers contact us with questions about articles, or to praise us on what a good job we are doing. But our favorite form of reader communication is tech questions. Our Top Tech section is a place where you ask what’s on your mind, and we answer it. Got a trouble code? Wondering how to get your engine to make more power? Send us an email at jason.sands@sorc.com and we’ll do our best to answer it.
Anti-Cummins Swap
Question: I have a ’76 Ford Highboy with a 390ci gasoline engine and a four-speed that I use to haul my camper and occasionally pull a trailer. However, since subscribing to Diesel Power, I’ve gotten the itch to put a diesel in her. I’m looking to have about 400 to 450 hp and plenty of torque. The only thing is, I would like something a little different. My friends say go with a Cummins due to the ease of the swap, which may happen, but I would like to explore my options. I’ve always had a thing for Caterpillar engines. Do you think a 3116-, 3126-, or even a 3208-sereis Cat engine could be made to work?
| There is a reason so many people go to the 5.9L Cummins when it comes to swap time: They’re cheap, light (for a 5.9L diesel), and lots of parts are readily available. Unlike the Duramax or Power Stroke, the 5.9L Cummins was designed to be installed in boats, generators, and tractors—long before it was ever put in a pickup. That one-size-fits-all approach makes it much easier to swap into difficult applications like this Hummer H1.
I’ve also considered an International DT466, Detroit 6V53, or maybe even some sort of John Deere diesel. Could any of these produce my desired horsepower? I’m prepared for a certain level of fabrication, but nothing too daunting. My plan is to mate the engine to either a ZF5 or ZF6 transmission. Could either of those handle any of the engines I’ve listed? If the answer is no, do you have any other suggestions? One more thing, on account of the added weight, what’s my best way to beef up the front end a bit?
Ben Ward
Shellsburg, Iowa
Answer:Our standard answer for swaps is that yes, with enough time and fabrication, you can put anything into anything—it’s just a matter of how hard the swap will be. In your case, you have a few things going for you, and a few things working against you. The fact that you’re looking at older mechanical engines and transmissions works in your favor, as there’s no complex wiring to figure out, and very few sensors to swap over. As a downside, a lot of the engines mentioned are rare, expensive, heavy, or all three. The 6V53 Detroits can make good power (we’ve heard of more than 1,000 hp), but it is tough to find someone to build them right, and they are getting rare, so they’re expensive. Cat motors are enormous and heavy; the 3208 at about 1,800 pounds is almost two Cummins engines worth of weight that you’d be putting up front, which would undoubtedly require a custom front suspension. We’ve seen DT466 engines (which weigh only about 1,400 pounds) in Fords before, and they just barely fit between the framerails and required a body lift. An 8.3L C-series Cummins could be another choice, but for what you’re after (400 to 450 hp), it just doesn’t make sense to use an engine other than the 5.9L Cummins. They’re cheap, easy to work on and install, will meet your power goals with barely any modifications, and they’re a good 500 pounds lighter than any of the engines previously mentioned. Since you want a manual, they also have a lot of good transmission choices. We hate to tell you to shy away from being different, but in this case it may be better just to go with the flock.
Hunting for Hoses
Question:I am currently working on an ’04 6.0L-powered Ford, and I would like to replace all the hoses while the engine is apart. I mean cooling, heater, intake boots, everything. What is a good source for long-lasting replacement hoses for my truck?
Mark Brunson
Tucson, Arizona
| We’ve had our own troubles with intercooler hoses blowing off our trucks, and although a little hairspray on the inside will do the trick (and make it really hard to remove), eventually we’ll have to step up to some heavy-duty hoses and clamps that can move and stretch as boost hits instead of ripping apart.
Answer:There are a few different companies you can go to for replacement hoses of all types. You can always count on places like NAPA to get hoses, or order them from the dealership, but high-performance diesels often demand high-performance hoses. In many cases, the added boost pressure from turbo and fueling modifications can overload stock intercooler boots and clamps, resulting in a boot blowing off in the intake tract. When this happens, it will sound like a small compressed-air grenade went off in your engine bay, and all your boost will go away because there will be a giant boost leak. This is especially problematic when your truck is hooked to a trailer, as oftentimes creeping along at 5 mph is the only option in order to keep EGT down with no boost.
While stronger intercooler boots are available through most aftermarket vendors, complete sets including coolant hoses are a little harder to come by. One company we do know that sells them is Mr. Bob’s Silicone Hoses [(661) 245-0319, www.mrbobsdistributing.com]. Mr. Bob’s kits include just about every hose you will need and are made from heavy-duty silicone. Be prepared, though, because a full set of intercooler and heater hoses will run you about $500, as quality doesn’t come cheap.
Needing a Boost
Question:I have an ’07 Dodge 3500 with a 5.9L Cummins. It is stock except for an AFE intake tube. I’m interested in adding a manual turbo boost controller to up the boost in order to increase fuel economy and power. I’ve been told the stock turbo will only produce around 30 psi, but right now it won’t even make that much boost. Do you have any suggestions?
Sam Kennemer
via email
| Boost foolers are perhaps one of the most common modifications to ’03 to ’07 Dodges, as virtually any programmer you buy that adds more fuel and timing will throw a code.
Answer: There are a few different products out there that can increase boost on newer, electronically controlled diesels, and these items are commonly known as boost foolers. These small, electronic gadgets keep the computer thinking boost is low, so it will keep the wastegate shut for a longer period of time. Some programmers, such as the MADS Electronics Smarty, can fool the computer all by themselves and don’t need any additional help up to about 44 psi of boost. Other programmers or tuners will throw codes unless a boost fooler is added. The most popular boost fooler is made by Quadzilla and costs less than $100.
As for the stock turbo’s limits, they can be pushed to upward of 40 psi of boost, but the turbo will be on borrowed time and probably won’t make much more power than 30 to 35 psi. As boost goes beyond 20 psi, efficiency goes down, and the turbo heats up the air more and more. While boost may rise, the actual oxygen content in the cylinder won’t be that much greater, because hot air takes up more space than cool, dense air.
Lastly, diesels work in a different way than gasoline engines, so more boost doesn’t always equal more power. Just turning up the boost on a stock engine might net you 10 hp, but you’ll barely feel that on a 4-ton truck. Adding fuel and then cranking up the boost can give you hundreds more horsepower, but it’s both the fuel and air that does the job on a diesel. At stock power levels, increasing the boost will help reduce EGT while towing, which is a boost fooler’s main benefit.
