Redesigned combustion engine could boost performance – The Blueprint

Is this the development that will change engine performance forever?
Alice Cooke
Engines
Engine parts

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  • Transcend Energy Group says its new design will dramatically change combustion engines for the better
  • The secret of the design lies in the world's first two-piece connecting rod
  • But not everyone’s convinced of the company’s claims or the extent to which they’ll make a difference

Redesigned combustion engine could boost performance – The Blueprint
ICEs just got faster and more furious.
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Utah-based Transcend Energy Group arrived on the scene with a roar at this year’s SEMA show in Las Vegas. 

There, it told delegates about its small design change, which it said could significantly improve the performance and efficiency of internal combustion engines (ICEs).

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But why, when the world is trying to go electric? Well, according to Transcend Energy Group's chief product officer and president Jon Woodard, we haven't got anywhere near unlocking the potential of ICEs yet, so why move on?

“Combustion engines are due for an update and the future of electricity is further away than you think,” says Woodward. “It is a dream come true after so many years of iterations to finally see the technology of the Thunder Rod come to life and make a powerful impact.”

Additionally, he maintains that ICE's are “very inefficient” “…and after years of doing the same thing, engines have stagnated.”

Why did he do it? 

The answer to this is probably best left to the man himself. Jon Woodward says: “For decades, the internal combustion engine has stagnated — a lack of major improvements has left companies and teams starving for a competitive advantage. That changes today. With Transcend Energy’s all-new two-piece connecting rod, we’ve transformed the future of traditional engines and expanded the possibilities of racing teams and general manufacturers alike. And the best part is, this isn’t some costly and complicated engine upgrade — it all comes down to the simple piston rod.”

A rod for his own back (and engine)

So what is this wondrous design that’s going to make our engines all the more efficient, faster, and all-round better performing? The world's first two-piece connecting rod, that’s what.

Essentially, a connecting rod attaches the engine's crankshaft to the piston and is responsible for transforming the energy from the piston into rotational energy that spins the crank. In a conventional engine setup, the piston is a pivot point on the connecting rod.

But in this new design, a two-piece connecting rod, (amusingly dubbed Thunder Rod), the pivot location has been moved to the arm of the connecting rod, which creates a much more linear motion for the piston and increases the volumetric efficiency of the motor.

Or, if you want to get really technical, a secondary joint is added to the typical con rod design. The company claims this arrangement makes the pistons drop farther and faster when the crank's at a 90-degree angle, delivering better leverage to the crankshaft.

The design allows the piston to remain neutral on the load side and engage only when it is on the other side. This allows you to use the piston without a thick skirt, but it has also increased the overall weight of the piston. 

Woodard has said he isn't bothered by this though, as his team is confident that it does not affect overall piston speed in any way, even though it moves through different parts of the stroke at different rates.

But while he may not be fussed, others are less sure. Loz Blain, motoring journalist for New Atlas, says: “Many are not convinced, particularly given the current lack of third-party testing and the paucity of results presented by the company. The two-piece con rods are heavier than standard items, creating additional inertial forces that will increase substantially as the engine revs faster, so there's a good chance that even if there are low-end gains, they might come at the expense of high-RPM horsepower.”

Testing, testing…

Here’s the power chat for the petrol-heads (and let’s be honest, also those of us who just quite like a spot of engineering wizardry)...

Woodard and his team have focused their development work on 5.3 liter and 6.2 liter small-block V8 (LS) engines so far. When the team tested the Thunder Rod on a 5.3-liter V8 engine, the torque output obtained was similar to that of a stock 6.2-liter V8 engine, a gain of around 30 percent.

The team also found improvements in the compression ratio for a Thunder Rod-equipped 6.2 liter LS engine which recorded 198 psi, while a stock engine only manages 155 psi.

Back to reality

While these numbers are impressive, experts aren’t sure how they’ll translate into real-world conditions. Changes made to the connecting rod design also require changes to the piston head and camshaft designs. Until these changes are made and tested, the real effects of the design changes won't be completely understood. 

In the meantime though, there is some skepticism as to the validity of the company’s claims. Though one could argue that all new inventions must have their critics and doubters…

In the first instance, independent and nonprofit applied research and development organization, Southwest Research Institute's Kevin Hoag, says he remains doubtful: “It doesn’t sound like a very big effect. If that intermediate piece is fixed in there, I struggle to see how they are eliminating piston rocking or secondary motion of the piston.” 

He adds: “I would challenge them to actually provide the calculations and demonstrate that. I think that’s generally where this design is at. There are some things that are being changed, and what real effect they have needs both measurement and demonstration.”

Loz Blain, motoring journalist, agrees, saying: “Many are not convinced, particularly given the current lack of third-party testing and the paucity of results presented by the company. The two-piece con rods are heavier than standard items, creating additional inertial forces that will increase substantially as the engine revs faster, so there's a good chance that even if there are low-end gains, they might come at the expense of high-RPM horsepower.”

This story first appeared in our subscriber-only weekly Blueprint newsletter. Receive exclusive interviews and analyses like this, direct to your inbox every Sunday, by subscribing to IE+.