Twin-Turbo 427 cid LS Next Engine - Engine Builder Magazine

Twin-Turbo 427 cid LS Next Engine

Hoping to run low-7s or even sub-6.50s, Stefan Rossi's Sick Week changed on his very first run. Despite a crash, Stefan was unscathed and he and his team finished the week. The car features a twin-turbo 427 LS Next engine built by Stefan at his engine shop, ACE Racing Engines. Check it out!

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Plenty of people can relate to how much effort it takes to successfully complete a drag-and-drive event. The word success during these events can be measured in many ways, especially when things start to go wrong throughout the week. Following his Sick Week 2022 adventure, Stefan Rossi is someone who can empathize with almost drag and driver.  

Stefan Rossi and his ACE Racing Engines team showed up to Sick Week in Bradenton, FL all the way from Torrance, CA, where his air-cooled VW and LS engine shop resides. The last time we caught up with Stef, the engine builder was thrashing to get his 1966 Chevy II Nova completed in time for Drag Week 2021 last September.

As many of you know, Stef had to cancel his plans to drive out east to Michigan at the last minute – certainly not for a lack of trying though. When Sick Week was announced, there may not have been a happier person in the car community than Stefan Rossi. All that prior effort was not for naught – Sick Week was what he needed.

Stef’s 1966 Chevy II Nova would be showing up with a newly built, 427 cubic inch, twin-turbo LS Next monster under the hood. He was entered into the Unlimited Iron class and hoping to run under 6.50s.

“When [Sick Week] got announced, we were like, ‘Perfect, we could do that,’” Rossi says. “We had a week off before the event and we’ve been on the road for almost three weeks. We went to FuelTech for a week and had the car on the hub dyno. We broke the hydraulic roller horsepower record on the hub dyno at FuelTech. That was pretty cool to do. It made 2,312 hp to the wheels. It made around 2,700 hp to the flywheel.”

That precursor had Stef and his team expecting big things. During Sick Week, the Engine Builder magazine team got a number of chances to chat with Stef. In fact, on day one of the event, we saw Stef just moments before he took the track. We were a broken camera mount away from having a GoPro in his car for the first run. And, what a run that turned out to be. It set the tone for his Sick Week adventure, but not the tone he, or any competitor, wants.

“I ran a 7.63 crossing the line sideways,” he says. “Initially, it felt amazing. I did pedal it a little bit just before the eighth. I shifted, and then I saw fluid on the windshield. I braked, but it was too late. The back end swung violently and I tried to correct it. I pulled the shoot, cut the power and then it went over and slid down the right side. Although I hit the wall, I was lucky because I was trying to not hit the alcohol tank. It has a bar going around it, but that was my main worry when it was going over to the other side that it could crush that and alcohol could go everywhere and cause a fire.”

Stef told us on day two that the bottom radiator hose came out during the second half of the run, which explains the fluid. The adapter it was held in with got pushed out.

“I fixed that and put a different adapter on there, which is much better, but I’m still going to dump the water out of it when we do a pass, so I don’t have to worry about it and I can keep my foot in it without worrying,” he says. “I’m going to turn it down a little bit just to get some confidence back. We’ll probably take it down to like the 25-30-lb. tune versus the 35-40-lb. tune and then see what it does. I’m confident we could do low 7s in the car easily, if we really want to try and push it. When we sort all this out, maybe we’ll try and push it if we get to the last day.”

Getting to the last day would end up being the test for Rossi, and many other Sick Weekers. Unfortunately for Stef and his team, the day one issues weren’t the only thing that reared its head that week. However, Stef had absolutely zero intentions of giving up. Long days and longer nights, part swaps and lots of help from others got Stef’s 1966 Nova back to Bradenton on Friday. The overall effort earned Stef the ‘Sickest of the Sick’ award, which was a nice consolation prize for what he was willing to endure.

While that 7.63 ET was his fastest, Stef finished the week with a 10-second average despite all the obstacles thrown his way. Again, not what he wanted, but what was necessary. His 427 LS Next engine is still badass, and here’s what Stef’s setup includes.

Stef has owned the car since 2016, and wanting to compete in more events like Drag Week and Sick Week, the engine got a big overhaul in 2021. It features a Dart LS Next2 block with 1/2″ head studs and 1/2″ main studs, a billet crank, billet aluminum rods, custom Ross pistons, and Total Seal gapless and gas-ported rings.

Up top, the engine features Dart cylinder heads, a custom hydraulic roller camshaft from Brian Tooley Racing, a Shaun’s Custom Alloy billet intake, as well as twin Garrett GTX5533R 88mm Pro-Mod turbos with Turbosmart electronic wastegates.

Rossi also employed a six-stage Dailey Engineering dry sump oiling system, an RCD gear drive, an Aeromotive fuel pump, a FuelTech FT600 ECU, and a Hughes Performance Powerglide transmission with a Gear Vendors overdrive. The car also has two fuel tanks – one for alcohol on the track and a 20-gallon fuel cell in the rear for the street.

Despite already having a six-stage dry sump oiling system, Stef told us he’s planning to add a seventh stage. That way each turbo will have its own oil supply. Currently, Stef has a Y feeding both turbos. The 427 has a 10.8:1 compression ratio and is capable of nearly 3,000 horsepower!

“The Nova has a 25.1 chromoly tube chassis car with a Strange Pro-Mod modular rear end and is built to be driven on the street,” Rossi says. “We are aiming to get the car to do sub-6.50s. The idea of the car/engine is to show people what can be done with a 9.240” deck block and the modern tech now available with hydraulic roller set-ups versus the traditional, big cubic inch, solid roller big blocks. I want to thank all the vendors that have been involved with this. We couldn’t have done it without any of them.”

Sickest of the Sick award

Engine of the Week is sponsored by PennGrade Motor OilElring – Das Original, Scat Crankshafts and Engine & Performance Warehouse Inc./NPW Companies. 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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