Milodon came up with a custom dry sump oil pan design for the project to meet Dorton’s spe
Mast Motorsports has been working with the LS engine package for years and has experience designing a lot of their own parts for the engine-and the engine builder believes it can bring an effective spec motor to the racing market based on LS technology. Of course, NASCAR has been doing that for years with its spec motor that is legal for a few different touring series, including the Camping World Truck Series, but the Mast version includes a lot more race-ready components. We used one of Mast Motorsports' own creations to power our own Project G.R.E.E.N. Late Model, Circle Track's science experiment to see how stock car racing might look running alternative fuels.
"Basically, what we're offering is anything from about 500 horsepower to 700 horsepower and above," explains engine builder Horace Mast. "We we do different from anybody else is we feature electronic fuel injection and we like to use our own cylinder heads to help control the power curve. We have about 11 different cylinder heads that we can choose from."
One of the reasons that fuel injection technology has been slow to catch on in circle track racing is because of fears that it can be a new avenue for cheaters to gain an unfair advantage. The electronic computers can potentially be hacked for a number of nefarious purposes. Depending on your preference, it can be possible to do anything from adjusting the fuel curves to make more power to actually installing traction control. But after extensive research and development, Mast believes he has a solution for all that.
"We have developed our own ECM (electronic control module) that's very secure and well protected," he says. "It's not like a GM or some other control that wasn't designed explicitly for racing and doesn't require the same safeguards to keep someone from cracking into it.
"Our electronic control is heavily safeguarded and single-password protected, which means that you would have to know the password specifically for that serial number and that ECM for it to work. The other thing we've developed with our ECM is we can control which parameters the team or racing series has the ability to change. So we can control specifically what is allowed to be adjusted and lock out everything else if the racing series wants."
Mast says that the ECM actually protects his spec engines from cheating more than the traditional carburetor as well. He explains the engine is tuned so that if a team tries to make external changes to the engine to the electronic ignition, it will almost always hurt power instead of helping it.
Mast's spec design is also unique because it utilizes a drive-by-wire throttle instead of a direct linkage with the intake manifold. This adds in an extra level of control for the engine builder that Mast says he takes advantage of to make the engine more driveable.
The A4MP Sprint motor isn’t currently legal with the RHS LS race block that you see here,
"Our main goal with these spec engines is to provide the most energy possible to the rear wheels," he says. "And that's not necessarily accomplished by making the biggest peak horsepower number that a lot of other guys like to brag about. We concentrate on the torque curve and also the throttle response to make the engine more raceable. The throttle system helps us because we can use it as a tuning tool to improve how quickly any change the driver makes with his right foot until he feels it in at the rear wheels. The car becomes more responsive to his inputs so he becomes more comfortable racing it."
When making the switch from a traditional carbureted race engine to a fully electronic spec engine, Mast says the switchover isn't as difficult as you might imagine. The LS block uses the same bellhousing pattern, so engine mounts will be the only change you have to make to the chassis-and that's not even necessary if you're using mounting plates. You will, however, have to add a return fuel line, a higher pressure fuel pump capable of at least 60 psi, and the rest is wiring. The ECM is fully self contained, so wiring it up isn't difficult, and the rest is the same with any carbureted car.
The Next Generation Sprint Ron Shaver was the lead development engine builder for a new spec engine design is purpose-built for Sprint Car racing. Like Mast Motorsports, he starts with an LS block, but the end result is quite unlike any LS engine we've ever seen.
Dubbed the A4MP engine (for Alternative 410 Motor Program), this spec motor isn't intended to race in a class all its own. "There's already enough classes out there for Sprint Car racing," says Donny Schatz, four-time World of Outlaws Champion, who worked closely with Shaver on the motor's development. "The last thing we need to do is create another class that's going to split the fields even further. We already have the 305s, the 360s and the 410 racing classes. This A4MP motor is designed to be able to race alongside the 410's and give racers an option that's a lot more affordable. Should it put out into its own class all by itself, our goals have failed. But if we can use this motor package to get more people to the track racing each other then the sport as a whole will be healthier."
The basis for the A4MP motor is an LS block and cylinder heads, but to keep it looking and feeling like a real Sprint Car motor, the design retains the iconic Sprint mechanical fuel injection and oil pump hung off the front of the engine. It does, however, ditch the magneto ignition for a more standard unit that provides a full 12 amps all the way down to idle.
Sprint Car racing icons Donny Schatz and Ron Shaver played a large role in the development
Schatz says that the A4MP motor can be built by any engine builder and will sell for somewhere around $20,000 complete. Comparing that to a full-blown 410 motor at anywhere between $40,000 to $55,000 makes it quite a steal. And like all the other spec motors we've talked about, the A4MP can go quite a bit longer between rebuilds. Schatz says this design should be able to race 20 to 30 full events before requiring a rebuild. On the other end of the spectrum is the current state-of-the-art World of Outlaw Sprint Car motor that Schatz says has to go back to the engine builder for a rebuild after just eight races.
But even though there is quite a bit of cost difference, the A4MP can be competitive against the fully built 410s. "The torque curve is just tremendous," Schatz says. "The rpm is limited to about 8,300 because of the hydraulic lifters, but on the smaller tracks (1/2-mile and under) this thing can really run with any of the 410s out there. On the bigger tracks it has trouble keeping up but you're not on those very often.
"The goal," he continues, "is to provide the weekly racer with a sound alternative that is competitive and fun to race. He doesn't have to spend as much to buy one and he doesn't have to rebuild it nearly as often, so he can afford to race more. And then when the travelling series come to town, it's still competitive against them so your local racers can go out and compete against the name guys to see how they stack up."
You may have noticed that earlier we mentioned that anyone will be allowed to build the A4MP engine. Instead of going with a single builder and an elaborate sealing system like many spec and crate motor's have resorted to, the A4MP has a unique plan to control cheating. Any engine builder that wishes to build his own motor will have to put up a $300 bond. Once bonded he can build all the A4MP engines he can sell, but if any engine is found to be illegal that bond will come due in the form of a $10,000 fine.
Yes, that's right: ten grand for cheating. We'll be interested to see how well this works but we can't imagine a better way to keep engine builders from going outside the rulebook than hitting them where it hurts-the checkbook.