Mast Motorsports Ls7 Crate Motor Block

Design Philosophy
Not long after walking through the doors at Mast Motorsports, it's refreshingly obvious that the place isn't run like your typical engine shop. While the company's massive facility-complete with four dyno cells, a machine shop, and engine assembly room-is very impressive, it's not what makes the place stand out. What's most unique is Mast's meticulous approach to not just assembling motors, but designing them as well. A mechanical engineer by trade, shop owner Horace Mast takes his engineering seriously. "Our goal is to apply a true engineering methodology to our crate engine packages," Horace explains. "Making lots of power isn't good enough. Our engines must also provide OEM-caliber durability."

To accomplish this, every Mast engine combo is subjected to a grueling seven-step design process. The first step involves using cutting-edge computer software to optimize engine parameters such as bore and stroke dimensions, port volume, compression ratio, valve size, and cylinder head flow. Next, a prototype motor is built using top-notch components. After designing four to five custom camshaft profiles using engine simulation software, they are all dyno tested to see which one works best. Afterwards, the air/fuel ratio is fine-tuned on the dyno to maximize volumetric efficiency, then the spark maps are established for optimized torque and power. Only after installing the motor in a test vehicle for real-world testing and final tuning changes is it approved for production. Like we said, Mast's crate engine packages are thoroughly engineered, in every sense of the word. Currently, the company has a plethora of naturally aspirated and supercharged Gen IV engines including L92s, LS3s, LS7s, L99s, LY6s, and aftermarket-block-based combos. Additionally, Mast offers engine packages for marine and airboat applications, as well as turnkey short-blocks.

  • Mast Motorsports Ls7 Crate Motor Gm Head Castings
    The LS7 SS utilizes factory GM head castings to which Mast applies its own CNC machining to the ports and combustion chambers. Working in concert with Mast's valve job, the tweaks boost airflow from 370 to around 400 cfm.
    The LS7 SS utilizes factory GM head castings to which Mast applies its own CNC machining t
  • Mast Motorsports Ls7 Crate Motor Valves
    The LS7 head castings are fitted with 2.20/1.625-inch Ferrea hollow-stem valves. While the intake valves retain the stock diameter, the exhaust valves are slightly larger than the stock 1.61-inch pieces to increase flow. Keeping them out of float are Mast dual nitride springs with 410 pounds of open pressure held in place by titanium retainers.
    The LS7 head castings are fitted with 2.20/1.625-inch Ferrea hollow-stem valves. While the
  • Mast Motorsports Ls7 Crate Motor Hydaulic Cam
    To achieve its goals of big power and good street manners, Mast uses a custom 246/260-at-0.050 hydraulic cam with 0.659/0.666-inch lift. It's ground on a wide 114-degree LSA to improve idle quality. The GMPP lifters, which were designed for the Cadillac CTS-VR factory race car, feature a ceramic check ball that enables them to operate at engine speeds up to 8,500 rpm.
    To achieve its goals of big power and good street manners, Mast uses a custom 246/260-at-0
  • Mast Motorsports Ls7 Crate Motor Rocker Arms
    Like the timing set, the Mast 427 uses factory LS7 rocker arms, as they're plenty capable of handling the motor's 7,250-rpm rev limit. Note how the intake rockers are offset to enable optimization of the port geometry.
    Like the timing set, the Mast 427 uses factory LS7 rocker arms, as they're plenty capable
  • Mast Motorsports Ls7 Crate Motor Intake Manifold
    A stock LS7 intake manifold comes standard on the Mast 427, but our test subject was equipped with a FAST LSXR intake instead. It's fed by a stock 90mm throttle body.
    A stock LS7 intake manifold comes standard on the Mast 427, but our test subject was equip
  • Mast Motorsports Ls7 Crate Motor Pedal
    One huge advantage of Mast's standalone ECM is that it's compatible with the factory drive-by-wire throttle-body using a GM gas pedal that's provided with the crate engine package. Not only does this yield the ultimate in throttle actuation precision, it means that there's no throttle linkage to hook up, further simplifying the installation.
    One huge advantage of Mast's standalone ECM is that it's compatible with the factory drive
  • Mast Motorsports Ls7 Crate Motor Dyno
    Mast dyno tests every crate motor that it ships. During the R&D process, Mast calibrates each specific combination at 160 different rpm and load points, from idle to redline. This involves painstakingly dialing in the air/fuel ratio using a modeled speed-density strategy that calculates airflow using throttle models, pressure models, and injector models. The M90 ECM also utilizes an octane-learn function that can adjust the spark maps automatically for octane ratings that range between 87 and 93.
    Mast dyno tests every crate motor that it ships. During the R&D process, Mast calibrates e
  • Mast Motorsports Ls7 Crate Motor M90 Ecm
    The M90 ECM is durable enough to survive harsh marine applications, so it can be mounted just about anywhere in a car. For easy access, mounting it on the firewall is a viable option, eliminating the need to snake the harness through the interior.
    The M90 ECM is durable enough to survive harsh marine applications, so it can be mounted j
  • Mast Motorsports Ls7 Crate Motor Car
    It's one thing to brag about dyno numbers, but the true test of horsepower is at the dragstrip. Strapped inside a full-weight street/strip Malibu with a stock-style suspension, Mast's 650hp LS7 SS propelled this sled to deep 10-second e.t.'s at nearly 135 mph.
    It's one thing to brag about dyno numbers, but the true test of horsepower is at the drags