Compound Turbo 5.9L 12-Valve Cummins Engine - Engine Builder Magazine

Compound Turbo 5.9L 12-Valve Cummins Engine

Dakota Sargent has a background in diesels, mining equipment, on-highway, over-the-road trucks, and as a U.S. Air Force mechanic, but it has been the light-duty diesel work that has prevailed. He founded Full Hook Performance a little more than a year ago, and is cranking out killer builds like this compound turbo 5.9L 12-valve Cummins. Check it out!

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At just 27 years old, Dakota Sargent is one of those guys who, once he fixates on a goal, he doesn’t stop until it’s achieved, and achieved to the highest degree. Dakota already has a rich and experienced work background considering he’s under 30 still, and today, his focus is on growing his diesel business, Full Hook Performance, located outside Las Vegas in Indian Springs, NV.

Dakota has been into diesel trucks since just out of high school when he went to college at Northwest Kansas Technical College in Goodland, KS. He graduated from their two-year diesel program with an associates degree in diesel technology.

Dakota Sargent is just 27 years old and is the owner of Full Hook Performance.

“Throughout school, I was working at a truck shop after hours to get myself through college,” Sargent says. “Once I graduated, I moved to Harrisonburg, VA… and I worked for Freightliner. Most of my career was in the on-highway, over-the-road trucks. Once I moved back to Nevada, I started working on mining equipment as a field mechanic and as a shop mechanic for a few years.

“Now, I’m currently a contracted employee for the U.S. Air Force as a mechanic, as well as running Full Hook Performance after I get off my day job. The goal is to very soon just do my own thing with Full Hook Performance full time. We’re getting really close to that point.”

Full Hook Performance specializes in building 5.9L 12 valves, P-pumped 24 valves, VP44 24 valves, and does manual transmission work too. In addition, Dakota also started a suspension division of Full Hook Performance that manufactures high-quality, billet aluminum, double adjustable control arm kits for ‘94 to 2013 Dodges.

FHP’s double adjustable billet control arms

“Full Hook Performance does engine building, transmission builds, as well as suspension work all under one roof,” Sargent says. “With most of our engine builds, we don’t see the truck. The customer supplies an engine and we build it to whatever power goal they want. We’ll do the build in-house and give them an engine you can pretty much feed your newborn baby off of – at any power level.

“What started the suspension side of things was my personal truck, a ‘98.5 Dodge with a P-pumped 24 valve. Once I got it to 700 horsepower, I wanted to turn it into a street truck. It was lifted and didn’t feel very stable down the highway or when we were doing a full pull or anything like that, so I wanted to set the truck back to stock height and I noticed a flaw in the industry of high price, low quality suspension parts for trucks ranging from ‘94 to ‘13. As a mechanic, I can see things and point out issues that I would change. I kept surfing the internet, looking for a suspension kit to put my truck back to stock height with the control arms, and none of them caught my eye, so I made my own.”

You might already be getting the sense that Dakota has been operating Full Hook Performance for years now, but he actually just founded the shop in April 2020.

“I run my company out of a small shop (30×25) that I rent from my buddy,” he says. “His son is actually my only employee, so it’s just myself and Anthony. He and I are putting in 18-19 hour days, seven days a week. Anthony is only 18 years old, but the kid is an absolute machine. He doesn’t ever complain, no matter how many hours we work and how late and how many days a week we work. He’s always right there by my side, learning and just trying to absorb as much knowledge as he can. I hope within the next two to three years, he can build these engines without any of my help. That’s the goal.”

One of the other goals for the shop is to keep growing the engine building side of the business based off of strong demand for Full Hook’s engine work currently. As that continues to ramp up, Dakota says a larger shop space is in the plans too.

“I’m working on building a new facility on my property that I can work out of full-time,” he says. “My end goal is to be able to do all of my engine machine work in-house, because I do outsource my machine work to a local machine shop in Vegas called Heads By Rick (HBR Competition Engines). They do all our blocks, cranks and our head work for every engine build we do. We’ve been using them for about a year now and we really like the work that they’ve put out for us.

“However, my goal by the next two years is to have my own machines set up to bore, hone, deck, and line hone blocks. I want to be able to do all my own head work because it is really tough to find good machine shops nowadays. I just want my turnaround time to be extremely fast and be able to check every bit of the work that comes out of our shop with our name on it. I want to know exactly what’s done to it and know that it’s done right.

“I’m really trying to expand and really perfect everything before I take that leap of leaving my day job and doing this full-time because our engine building has really taken off in the last four to five months.”

One of the bigger engine builds Dakota recently finished was for a good buddy of his named Taylor Swanson who owns Northern Nevada Window Tinting in Reno, NV. Last season, Taylor picked up a mid-‘90s Dodge Ram 2500 single cab, long bed and was running the truck with a single charger (S369), a Farrell Diesel 215 pump and 5×25 injectors, which provided 785 hp. Like any diesel fanatic, more power was on Taylor’s mind.

Dodge Ram 2500 single cab, long bed

“We’ve built a couple of trucks together, but nothing too crazy on the power scale,” Sargent says of his friendship with Taylor. “After the season ended, he had called me and said some guys were talking smack to him, so he was ready to go all out on this thing for next season.”

The engine is a 5.9L 12-valve Cummins, which Taylor’s guys pulled out of the Dodge 2500 and drove down to Full Hook Performance for teardown.

“Anthony and I ripped it down and sent it over to HBR,” Sargent says. “We bored it .020˝ over. We went with some Mahle high-performance cast pistons with coated skirts. Josh McCormick relief cut the pistons for us. We went with .080˝ reliefs in the tops of the piston for valve clearance with a Stage 5 Colt cam. The Stage 5 cam is a 199/218 lift cam. We’re running the 1.45 common rail tappets in it for the wider footprint on the cam lobes. We TIG welded the cam gear and crank gears.

“We went with a Hamilton Stage 2 head with oversize valves and Hamilton conical valve springs. We weren’t 100 percent satisfied with the valve job, so we ended up reworking the valves on it to our liking. The head is also fire ringed.

“We ended up running some Dynomite Diesel Super Mental injectors. They did a custom nozzle for us. We have a Stage 4 Farrell Diesel 215 pump. It’s got an attitude adjuster and minor additions to the Stage 5 pump. It’s got 5,000 rpm governor springs in it. We did a balanced rotating assembly with Wagler Street Fighter rods with the half-inch L19 rod bolts. Adam Aquino set us up with those.

“We used Mahle H-series bearings throughout the whole engine – mains and rod bearings. We’ve got billet piston cooling jets and billet freeze plugs. We’ve got a Keating Machine billet tappet cover with the baffled breathers. We’ve got a Keating Machine one-piece billet valve cover. We did Manton 7/16ths chromoly hybrid pushrods with the 24-valve ball and 12-valve cup. We went with ARP 625 head studs. We’ve also got a Gorilla girdle on the bottom end.

“Up top, we’ve got a Steed Speed T4 manifold with an EvilFab Performance compound turbo kit. We went with a side-by-side S472 SXE over an S488 SXE turbo. That’s a V-banded, TIG-welded, full stainless kit that also got polished. The charger set up from EvilFab are well over 1,000-horsepower chargers, and the cam is going to really help spool and fueling.”

Since the rebuilt 5.9L 12 valve will be spinning much higher rpms and have high boost, Dakota wanted more piston to valve clearance in the engine.

“The engine is probably going build close to 100 psi easily with those chargers, so we got thicker gaskets from XDP, so we had a little bit more valve to piston clearance,” he says.

5.9L 12-valve Cummins

The Cummins build also got outfitted with a Fluidampr balancer and a Keating Machine billet front cover, but the lift pumps were an area that got special attention.

“We needed as much fuel as we could get, so we decided to run twin AirDog 165 4G lift pumps,” he says. “Kevin at AirDog actually internally bypassed the regulators on the pumps, so they’re running full fuel – over 300 gallons per hour – straight to the P pump. He also set us up with their new adjustable boost reference return regulator.

“In our shop, we TIG-welded our own fittings to run high flow on the return and step up from a 3/8ths return to a 1/2˝ return to the regulator. That way we can really dial in our fuel pressure at idle, and then once we come onto boost, it’s always going to maintain pressure without heat soaking the pumps. That really stepped up our fuel game. We’re feeding the P pump on the front and the side – one AirDog feeds the side and the other AirDog feeds the front of the P pump, which really helps with cooling the pump down and delivering as much fuel as we possibly can to it.

“We’re also running the 1/2˝ return all the way back to a dual sump. One of them uses the return from the injection pump all the way 1/2˝ back. The second port on that feeds one AirDog and then the second sump feeds the second AirDog. Both AirDog returns have a lower return rate because of the internal bypass on the regulators, so we were able to combine the two regulated returns off of the AirDogs to one single port on the sump.”

In addition to all of the goodies Full Hook Performance already has on the engine, Taylor also wanted some nitrous at his disposal, so Dakota added a single stage, 200 shot of nitrous on it.

“I would say the truck is going to do every bit of 750-800 horsepower turned all the way down with the charger and fuel set up we’ve got running to it,” he says. “The power goal that we set was 1,000-1,300 hp. We will really be fuel limited on the Stage 4 pump before we need to step up to a 13mm pump, but we really wanted the truck to have street manners still, so if he wanted to, he could take it out and rip it around on the street.”

Aiding in the truck’s performance is a fully built transmission done by a local Reno shop, which also features a quad disc converter, a Muldoon’s full manual valve body and a ratchet shifter.

Some of the final touches on the full build include Full Hook Performance’s double adjustable billet control arms, eliminating the vacuum pump for just a gear-driven power steering pump, a full wiring tuck in the engine bay, and a battery relocation to the bed.

“It’s a very nice build,” Sargent admits. “It’s a looker and it definitely walks the walk and talks the talk. The truck is mainly a dedicated drag truck, but he’s still got a full interior and full bed. He will also take it out on the street and play around with it. We are going to set the truck up with air conditioning, so he does have that luxury of air conditioning with a 1,000-plus horsepower truck.”

Currently, the truck doesn’t have a cage appropriate for the new horsepower at the track, but plans are in the works to get a cage in the truck soon. That aside, Dakota told us they built the whole set up for this 5.9L 12-valve Cummins in just three days.

“We plumbed the whole fuel system, built the entire engine from a bare block up and were able to break the cam in on my engine running stand and then do a hot retorque and slap it in the truck by the end of a weekend.”

As you can tell, Dakota has the drive and determination to succeed at anything he does, and Full Hook Performance is a name we have no doubt you’ll be hearing much more of.

“My goal in life is to do this full-time,” Sargent says. “I know I’ve got the will to make it happen. Once I set my mind to things, I don’t really ever take no as an option. Hopefully I can keep doing more badass builds.”

Diesel of the Week is sponsored by AMSOIL. If you have an engine you’d like to highlight in this series, please email Engine Builder Editor Greg Jones at [email protected].

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