6.6L LBZ Duramax - Engine Builder Magazine

6.6L LBZ Duramax

When a rebuild went wrong at another shop, Sin City Diesel & Off-Road was entrusted with this 6.6L LBZ Duramax engine. Find out what went into making this 200,000 mile engine run like new again!

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Like most kids who grew up loving cars and trucks, Frank Davis had an obsession with Hot Wheels. That $1 obsession turned into a very, very expensive one – rebuilding diesel trucks and engines!

Along with loving Hot Wheels, Frank learned to automotive skills by helping his family work on their vehicles when he was growing up, and his step dad taught him a lot about engines as well. The bug for engine work meant Frank ended up going to a vocational high school where he took courses on automotive and diesel mechanics.

“Initially I was going to do automotive, but ended up deciding I wanted to do diesel,” Davis says. “I started out on heavy-duty big rigs and then I ended up getting a job at a local shop learning the smaller diesel stuff – Duramax, Cummins and Powerstroke. From there, I bought an ’06 Duramax LBZ and I started tinkering with it. That tumbled into what we’ve got now at Sin City Diesel.”

Davis started Sin City Diesel Performance, a full-service diesel shop located in Las Vegas, in May 2018. Frank quickly joined forces with his business partner, Dennis, who owned an off-road shop specializing in Jeeps and 4x4s. Today, the two shops go under one name – Sin City Diesel & Off-Road.

“We recently rebranded and combined both shops,” Davis says. “I run the diesel department and my partner runs the off-road side. As far as the diesel side, we were doing a lot of 6.0Ls at first, and that’s kind of what we became known for until a couple of Duramax and Cummins started trickling in. The next thing you know, we’ve got a whole mix of everything now.”

Sin City Diesel & Off-Road encompass two shops that are 4,000 sq.-ft. each. The Sin City Diesel side employs three full-time technicians, one apprentice and a service writer. The shop has seen a lot of growth in the short time it’s been open, and a new, bigger facility is in the works for 2020.

“We both have a ton of confidence in this business, and so far we’ve been very fortunate with our growth, especially on the diesel side,” he says. “We’re in the process of building a new facility out in the north part of Vegas. That’s our next phase and we hope it will be done next summer. It’ll be about a 17,500 sq.-ft. shop with a separate engine building room, parts room, offices, and a 2,500 sq.-ft. showroom. We’re just trying to do good work with good people and use only the best parts.”

In addition to its repair work, Sin City Diesel tries to do as much performance diesel work as it can, but because Vegas isn’t a huge market for that work and the shop is in an emissions county, that limits how much horsepower the shop can do.

“A lot of what we do is for guys who do heavy towing and they want to upgrade their trucks and have it run cooler, since obviously it’s hot out here in Vegas, Arizona and California,” he says.

The shop recently had a customer come to them after he was unhappy with another shop’s rebuild on his 2006 6.6L LBZ Duramax.

“The customer has had this truck since brand new,” Davis says. “He owns a local landscaping company, so this is his weekend warrior truck. The customer had blown the original motor. He took it to a shop here in town and they were supposed to have put in new injectors, supposed to have built the trans and put on a compound kit – an S475 turbo. They also did the tuning.”

The customer wasn’t happy with the rebuild that he had gotten, so he brought the truck in to Sin City Diesel.

“It was leaking out of every orifice,” Davis says. “That was the main thing. The oil pan was leaking. The valve covers were leaking – everything was leaking. Fortunately, the customer was willing to spend the money to do it right.”

The shop got to work and pulled the motor to reseal it. With the engine apart, Davis noticed the injectors the other shop put in were a cheap brand and wouldn’t work well with the customer’s power goals.

“We settled on a 10mm Exergy pump in the valley – a single CP3 pump – and 60% over Exergy injectors,” Davis says.

In addition, the whole turbo system was torn apart and in need of serious attention.

“The only thing we kept was the turbo and the intake pipe,” he says. “We had our fabricator make a new crossover pipe for the hot side of the atmosphere turbo to the smaller turbo because we ended up going with Screamin Diesel Performance. They have the two-piece billet Y bridge and we went with that for increased airflow over the stock intake system. Now, this system is making 50-60 lbs. of boost, so the stock system wasn’t going to hold up.”

Sin City Diesel also ended up studding the motor while it was apart, pinning the crank and pinning the water pump, and keywayed the cam so the customer wouldn’t have to worry about that spinning off.

“We stayed with the stock bottom end and just sent it to the machine shop,” Davis says. “They went through it and everything checked out. The engine block checked out fine, so that’s going to remain stock. The heads ended up checking out just fine. We ended up doing a valve job and putting in new valve guides. We also ended up having to replace the torque converter because it was supposed to be a billet triple disc, but it ended up being a Chinese or some local-built single disc piece. We put in a Goerend triple disc converter with a billet stator, so it’ll hold whatever he throws at it.”

Now that Sin City Diesel has this 6.6L LBZ Duramax setup properly, the customer has all the makings for about 600-700 horsepower.

“We’ve got Starlite Diesel tuning in there and they’re doing the EFI Live for it,” Davis says. “We have the S475 overstock Borg Warner turbo and the fuel system to support everything too. The next step with this truck is doing an Alea Leather kit on the inside to match the custom powder coating we did on the engine. The customer wanted blue and white, so the custom leather interior will match that. We’re also going to pull the trans and go through that to make sure it’s ready to hold the power the new motor has.”

The Diesel of the Week eNewsletter is sponsored by AMSOIL.

If you have an engine you would like to highlight in this series, please email Engine Builder magazine’s Editor, Greg Jones at [email protected].

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