Engine Build and Dyno - 410 Sprint Car Build
Our sprint car has had a busy year. After we finished assembly of the car as a roller with a mock up engine, it has travelled the country with the National Sprint Car Hall of Fame. But the heart of a sprint car is its engine, so we hit up Zach Woods at Speedway Motors Racing Engines to help us out. Zach can do it all, but he specializes in circle track engines, and sprint car engines in particular. So, he jumped at the chance to build a state of the art 410 to power our sprint car.
Spend a little time in the stands at a 410 race and you’ll hear over 900 horsepower spinning 8000 rpm, lap after lap. It takes serious hardware and meticulous assembly to make that possible. Here is a rare glimpse at what it takes to build a competitive, reliable 410 sprint car engine.
Zach started with a Donovan 410HC block with a raised cam and 4.130” bore. At this level of racing, every ounce counts, so these blocks are CNC machined to eliminate every bit of unnecessary weight. The result is an aluminum block that looks like a piece of jewelry. After surfacing on the shop’s Rottler CNC equipment, the cylinders were honed and the block was washed.
Assembly of the bottom end started with the 3.800” stroke, 8-counterwieghted Callies Magnum XL crank. Like all the other pieces in this engine, this crank looks a little unconventional if you’re used to standard small block stuff. The counterweights have been scalloped and lightened significantly to reduce mass and harmonics at the insane rpm that this engine will be seeing. The trick crank will spin inside coated Clevite bearings and splayed forged steel main caps will keep it where it belongs.
The crank is swinging 6”long Dyer’s H-beam rods with ARP 625 bolts. These are attached to forged CP-Carrillo pistons with a 4.78 cc dome. If you’re wondering about the little holes in the top, so were we. Zach explains that the vertical gas ports go into the top ring land and use cylinder pressure to push out on the rings and help them seal.
On to the cam. The Huggins solid roller measures 266/268 at .050 and the .430” lobe lift translates to around .760” at the valve. The 55mm cam allows for a larger base circle, minimizing the side-loading of the lifters with the aggressive lobe profile. To that end, Zach also chose .904” diameter Isky Red-Zone roller lifters. The larger diameter here allows for a bigger roller, also causing more favorable geometry with minimal side-loading.
Like all the other pieces of this engine, the cylinder heads are works of art. Based on All-Pro heads with a 13-degree valve angle, they were fully CNC machined by 1 Way Technologies. Zach filled them with CRN coated 2.20”/1.60” Manley titanium valves, Manley 441446SF valve springs, Manley TensiMax retainers and Ti locks. T&D Machine steel rockers were selected with a 1.75 ratio on the intake and 1.70 on the exhaust.
More trick stuff on the front of the engine. A Shaver-Wesmar gear drive hides behind a KSE cover and water pump. The Barnes 5-stage dry-sump oil pump spins off the front of the cam and works with the Dan Olson 3-port pan and Saldana tank to keep the oil where it belongs.
Clearly this monster is going to need a serious induction setup. The Kinsler Beast injector is more than up to the task. Each throttle blade measures a whopping 2.90,” and combined with the Waterman pump that we installed in Episode 6, there should be more than enough air and fuel to go around.
Like just about every sprint car and Outlaw team around, Zach swears by the MSD 12LT Pro-Mag. These are trick because they eliminate the points seen in traditional mags and instead use FET technology in the Electronic Points Box. MSD tight-fit wires send the energy to NGK plugs gapped at .019”.
With assembly complete, the engine was rolled into the dyno cell. After some heat cycles and re-torqueing of the head studs, we were ready to make some pulls.
You’ve seen engines run on this dyno before. We’ve featured a few dyno pulls in past videos on some relatively mild, 400-500 horse street engines. It’s always exciting to hear these engines sing across the rpm range and see the power numbers. But this one is different. As soon as it fired up and settled into a rough, thundering idle, it was clear that this would be unlike anything that we had experienced before. However, for Zach and the Racing Engines crew, engines like this are part of a typical day. They conducted themselves like true professionals, making final tuning changes and checking everything over, while the rest of us danced around like excited kids. Then, with everything up to temperature, Zach pushed the lever forward and opened up the giant throttle blades on the Beast injector. The 410 didn’t miss a beat all the way up to 8000 rpm and filled the shop with a beautiful, ear splitting mechanical symphony.
In the end, the engine made 949.9 horsepower at 7200 rpm and 729.8 lb-ft of torque at 5700. That’s a lot of power for a small block Chevy with no power adders, but it’s maybe even more impressive that this engine can run flat out, race after race, night after night, at that power level.
As always, thanks to Zach Woods and the crew at Speedway Motors Racing Engines. Stay tuned for the next episode, where we’ll install the 410 and close out our sprint car build. See you next time!
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