V10 LS From XR10 Motorsports Unleashes 1,000 Horsepower
The possibilities with the LS platform are truly endless, so much so that some have gone to extremes to see what the engine platform can do with a cylinder count that isn’t eight. From Inline fours and V4s to V12s. GM itself even toyed with the idea of producing a torquey V10 to compete with the Ford and Dodge V10s in the heavy-duty trucks, but it never made it past the concept phase. XR10 Motorsports took GM’s idea and converted it from an iron block, fleet-duty idea to an aluminum block big-inch V10 LS performance monster.
If we told you that we discovered the V10 LS from XR10 Motorsports at SEMA this year, we wouldn’t be totally honest. We’ve actually been keeping an eye on these guys on social media for the past year as they’ve been developing the 10-cylinder and fine-tuning its output. Slowly but surely, XR10 Motorsports pushed the pump-gas, naturally aspirated V10 to over 1,000 horsepower.
GM Concept Roots
Before we see where XR10 took the LS V10, let’s recap its HD roots. GM had been flirting with the idea of a heavy-duty gas V10 to replace the dated big block and compete with Ford and Dodge since the mid-‘90s. When the LS debuted, GM began to take the daydream a little more seriously and began development on the LS-based 10-cylinder.
But it wasn’t until the Gen IV LS that they produced a few to test the concept. To put it into the simplest of terms, the V10 LS GM built was essentially a 10-cylinder version of the 6.0-liter LY6 heavy-duty gas truck engine. With an iron block, L92-based heads, a 4.000×3.622 bore and stroke, and the same low-octane friendly compression. The result was a 455 cubic-inch (7.5-liter) V10 LS, one cubic inch away from the 7.4-liter big-block.
The Next-Level V10 LS
XR10 Motorsports took the GM concept as a source of inspiration and made their own high-performance version. They kept the LS’s basic architecture, like GM did, but instead made the block out of aluminum, with reinforced webbing, a taller deck at 9.72 inches with thicker and longer sleeves to match, ¾-inch thick deck surfaces with 6-bolt head bolt provisions, and a 0.388-inch raised cam centerline. All of these features make it lighter than the iron GM concept block but stronger to handle big power, either NA or boosted.
For maximum flow, the cylinder heads were cast to resemble the best flowing LS heads GM produced: the LS7. These heads use off-the-shelf LS7 valvetrain components like rocker arms, valve springs, and valves. They flow over 400 cfm, which is what helped their test mule hit over 1,000 horsepower. Induction is a dual plenum intake to match the airflow requirements and dual 90mm throttle bodies.
At the front and the rear of the block, XR10 Motorsports kept everything the same as the common LS to make the V10 LS easy to bolt up transmissions and accessory drives. Due to the tall deck height, the engine is a little taller than production LS engines. And with the extra two cylinders, it shouldn’t come as a surprise that the length increased by about 4.400 inches. Weight didn’t increase nearly as much as you would think, with the all-aluminum V10 weighing only 438 pounds.
Earth Shattering Results
XR10 Motorsports built their test mule with the same bore and stroke as the infamous 7.0-liter LS7 V8: 4.125-inch bore and a 4.000-inch stroke. The result, with a custom hydraulic roller camshaft and pump-gas-friendly 12.5:1 compression, is a V10 LS that displaces 535 cubic-inches (8.8 liters) and makes 1,003 horsepower at 8,000 rpm and 756 pound-feet of torque at 6,300 rpm. But the sky is the limit with a max bore of 4.185 inches and more room for longer stroke crankshafts than the stock LS blocks can handle. XR10 Motorsports claims that they can build you a V10 that’s over 600 cubic inches. The price for this effortless 10-cylinder power? XR10 is not advertising prices just yet, but with effortless horsepower and torque and a unique exhaust note, we all know it will be worth it.
