Salt Report: Speed Demon Is Still The World's Fastest LS Engine

December 20, 2018 / by Jeffrey James Patrick

Update from the salt: Speed Demon is still the world's fastest LS engine and the team is looking to step that up even further! 

The Speed Demon team went to Speed Week 2018 with two main goals: claim the E/BGS record and bring home the HOT ROD trophy given to the fastest single pass of Speed Week. The trophy had been won by Speed Demon in each of the last seven Speed Week contests, despite increasing competition from Danny Thompson’s Challenger II and Team Vesco’s Turbinator II. However, after running four engines, three of which driver George Poteet used to make passes at over 400mph, and answering Danny Thompson’s 450mph run with a 452.255mph on the third day of racing, the Speed Demon team left the salt without a record and without the trophy.

Driver George Poteet is relaxed behind the wheel of the Speed Demon. Excellent salt conditions in 2018 made driving a much more enjoyable experience than in prior years.

The Speed Demon team currently holds the record for A, B, C, D, and F blown fuel streamliner, and wanted to capture the E record to fill out their dance card. For those that aren’t fully versed on Bonneville classes, they’re divided up by engine size, the type of fuel, and the type of car. The E/BGS record is for Blown (anything other than naturally aspirated) Fuel (anything other than the race gas supplied on the salt) Streamliner (cars with fully enclosed wheels) with designating an engine between 184-260.99 cubic inches.

Last minute electric checks sort out the sensors that lead to an early turn out on Speed Demon’s first pass.

The Speed Demon brought four engines to go after the trophy, the smallest of which is the E-class small-block Chevy V-8 that uses a 2.4-inch stroke to come in under 260 cubic inches. It was that baby small-block that was powering the Speed Demon streamliner on its first runs of Speed Week 2018. The first run ended before it even began, with George making an early turn out due to an electronics issue. They were soon back and ran 332.858mph with their next attempt that was also cut short. An inspection back at the pits revealed a valvetrain issue that would require a teardown. Because the Speed Demon’s chassis was designed for quick engine swaps, it was faster for the team to pull the E engine and drop in their A-class, 443ci V8 in its place than it was to attempt to address the valvetrain problem.

The 443ci LS engine is fed by the same 88mm Pro Mod turbochargers as the smaller engines. It uses a set of hard-anodized Diamond Pistons to handle the massive boost pressure.

Like all of the Speed Demon’s engines, their A-class engine uses Diamond pistons and Trend pushrods, but what sets it apart is that while the rest of their engines are based on Gen 1 Chevy small-blocks using Dart Iron Eagle blocks, their A-class mill is based on LS architecture and is topped with Dart 10-degree heads. At Speed Week 2017, George Poteet and the Speed Demon team used that LS to run 428.784mph and this year, with a better racing surface, it ran 448.508mph, ensuring that it’s the fastest LS engine in the world. They did learn a valuable lesson on that 448mph run: the engine’s belt-driven timing can only open the valves reliably to about 50 pounds of boost. When the team turned the wick up and ran 60 pounds of boost through the big LS it caused the timing belt to stretch and skip timing bad enough to bend valves.

The car’s two crew chiefs, Kenny Duttwelier, left, and Steve Watt, discuss the week’s strategy.

Still behind Danny Thompson’s 450mph pass in the Challenger 2, the Speed Demon team swapped in their third engine of the week into the car and were able to coax a 452.255mph pass out of the salt on Monday using their B-class, 388ci engine and take the lead in the race for the HOT ROD trophy. 

Danny Thompson had secured a record with his 450mph run, and so he and the twin-Hemi-powered Challenger 2 AA/BFS streamliner were out of competition, leaving Team Vesco as the remaining threat to Speed Demon’s dominance. For 2018, Dave Spangler was back in the driver seat of the Team Vesco Turbinator II streamliner, a turbine-powered car that is an absolute marvel of engineering. The previous year, the kinks were still being worked out of the freshly rebuilt car. This year it was different. After thrashing in the pits to get it ready for its first run of Speed Week 2018, a shakedown 384.906mph run on Sunday was promising. The following day, after Speed Demon’s 452mph pass gave it the lead over Danny Thompson, Spangler made a 463.038mph run to top Speed Demon.

An errant oil line caused a valvetrain failure on the Speed Demon E-class engine. It was replaced so that the LS engine could go in its place. A razor-sharp chop saw makes for clean cuts for a new fitting.

The Speed Demon crew kept at the fight for the trophy all week long, and ended up running the LS engine again after swapping on a spare set of heads, although it couldn’t better its previous 448mph run, again suffering from timing belt stretch. For their final attempt, the Speed Demon team installed their C-class engine, a 368ci version of their Gen 1 small-block formula. On their 12th  run of the week, it pulled harder than in any run in Speed Demon’s 400mph career, beating the previous best speed at the 2-1/4 marker by 8mph. Unfortunately for the team, George wasn’t able to make a complete pass and Turbinator’s impressive 463mph pass would take home the hard-earned trophy.

Speed Demon isn’t done racing this year, as the lessons from Speed Week 2018 have been learned and now their LS powerplant has gear-driven timing. The team will return to the salt. The goal: to try to make an SCTA record in excess of Danny Thompson’s 448.757mph effort and take back the unofficial title of world’s fastest piston-powered car. George Poteet is excited to get back into Speed Demon and co-crew chief Steve Watt is reinvigorated, “The salt is incredible, that’s why we’re going back!”

Topics: FEATURES, featured, CAR FEATURES

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