Building an engine yourself is something every hot rodder should try at least once. As gratifying as that experience may be, the smart hot rodders among us will simply order up a crate engine the second time around. With the competitive pricing of today's crate engines, it's becoming difficult for DIYers to save money by piecing together an engine themselves. Instead of waiting in line at the local machine shop for months on end, many enthusiasts find the immediate gratification of having a crate engine show up on your doorstep in just a few short weeks difficult to resist.
More than 20 years ago, Norris Marshall started building engines out of a small garage in Nebraska. A true hot rodder at heart, Norris built engines one by one for friends and fellow enthusiasts. Eventually, the growing popularity of his motors amongst drag racers, street rodders, and circle track racers prompted him to pursue engine building as a full-fledged career, and BluePrint Engines was born.
From the beginning, the plan was to develop and manufacture OE-quality engines for high-performance street cars. What started as a small catalog of performance crate engines has now expanded to include small- and big-block Chevys as well as LS-series offerings. BluePrint's broad product line ranges from value-packed 375hp first-gen small-blocks to high-tech 625hp fourth-gen engines to monster 815hp Rat motors packing 632 cubic inches.
Better yet, all BluePrint engines are backed by a 30-month/50,000-mile warranty. To get the inside line on what it takes to build top-notch crate engines—and get some more details on its line of proprietary blocks and cylinder heads, we recently chatted with Dru Freese and Chris Larson at BluePrint Engines.
Whether the procedure at hand is machine work, engine assembly, or dyno tuning; engine building is a highly specialized process, especially when those engines must appeal to a broad demographic with a broad range of preferences. As such, BluePrint Engines goes to great lengths to thoroughly engineer each of its crate engine packages from the ground up. "At BluePrint, we have a very strong engineering department. All of our engineers are car nuts just like the people they're building engines for, so they know what customers expect," Chris Larson explains. "When we design an engine from scratch, we analyze every last detail. New engines are first designed using advanced computer simulation software. This enables us to determine what compression ratio, cam timing, and cylinder head airflow we need to meet our customers' needs for power and drivability. Next, we determine which off-the-shelf components are available that meet our design goals, and which components need to be designed from scratch. Our design engineers will first draw up new components as a 3D model. This allows them to actually install the 3D model of a part onto a 3D model of an engine. Through computer animation, we can see how things will work together in a running engine. This is critical when you design high-stress components like crankshafts, rods and pistons. Additionally, 3D animation allows us to see how the parts interact and fit together. Our engineers can check clearances at that point before we go any further. From there, the parts are printed using our 3D printer. Again, we can assemble these parts together, this time using plastic prototypes. Once everything is validated, we can move on to the manufacturing process."
While some crate engine manufacturers keep costs down by sourcing parts from relatively unknown suppliers, BluePrint prides itself on working with the best aftermarket manufacturers in the industry. "BluePrint utilizes a combination of components manufactured by big-name aftermarket companies as well as parts that we have developed in-house. Our suppliers include household names like COMP Cams, Delphi, Mahle, Hastings, Melling, Fel-Pro, Cloyes, and Clevite," says Dru Freese. "When it comes to subcomponents, we always strive to deal directly with the manufacturer, particularly those that have a strong reputation in terms of engineering and quality control. Companies that develop products and have relationships with OE manufacturers fit this description very well. In order to warranty all of the engines we build, we have to source all our components from the best manufacturers in the industry."
Recently, BluePrint ramped up its product line with the addition of the LS-series small-block. Based on a brand new LS3 block and BluePrint's own proprietary cylinder head castings, these 427ci beasts kick out an impressive 625 hp. As no surprise, BluePrint's 427ci LS-series small-blocks are the product of years of intense R&D. "The LS engine platform, as designed by GM, is already an excellent product. For example, the LS3 cylinder heads are far superior to any factory 23-degree head used on the Gen I or Gen II small-block," Chris Larson explains. "We went a step further and developed a new proprietary BluePrint LS3 head casting by consulting with some of the best head porters in the country. In fact, our LS3 cylinder head was in development two years before we finally had what we wanted. Every prototype engine was dyno tested countless times to compare different camshafts, intake manifolds, and variations in intake port and combustion chamber design. We started out with combinations that we thought would work best for our baseline engine combos, and then addressed areas we felt could be improved until arriving at the best combination. It's not uncommon for an engine we are developing to be tested with dozens of different combinations of parts before finding the perfect formula."
As soon as GM's factory LS3 block hit the street, its large siamesed bore brought the potential for affordable, big-cube LS motors to the masses. Simply honing these blocks out to 4.070 inches and combining them with a 4.000-inch stroke nets an easy 416 cubic inches, which explains why that particular bore and stroke combination has become so popular with LS enthusiasts. BluePrint takes the displacement tally a few notches further by packing a 4.125-inch stroke crankshaft in its LS crate engines for a total of 427 cubic inches. While some engine builders contend that the stock cylinder sleeves are not long enough to support a 4.125-inch stroke, which can lead to piston rock and increased oil consumption at BDC, BluePrint worked with Mahle to figure out an effective solution. "Our chief engine designer was able to work with the engineers at Mahle to design a revised piston skirt to stabilize the piston at BDC," Dru Freese explains. "This eliminates concerns of piston rock and oil consumption. We can't be piston experts like a large OE piston supplier like Mahle, but we can work with them to leverage their technology to come up with something that solves the problem."
Camshaft duration plays a significant role in an engine's idle quality and drivability. Although BluePrint's primary focus is in the street engine market, customers still expect a healthy dose of power to go along with a smooth idle and a streetable torque curve, and striking a balance between both extremes requires extensive development work. Likewise, by maximizing cylinder head airflow, BluePrint is able to employ cam designs with shorter duration specifications and wider lobe separation angles to preserve drivability while still producing impressive hp figures. "The first thing we have to take into consideration is the application in which we are designing a new engine for. Once the application is finalized, we start the design process using computer simulation software, which gives us a good idea on determining camshaft specifications," Chris Larson explains. "This is definitely one of those areas where we do a lot of consulting and a lot of testing. Even though we have been designing crate engines for a very long time, it's still a good idea to consult with the camshaft manufacturers. After determining the basic architecture of the engine by analyzing specifications such as bore and stroke dimensions as well as cylinder head airflow, we then work with camshaft manufacturers to come up with three or four baseline camshafts we feel will work best in a given application. While dyno testing, we advance and retard the cam four degrees from the intake centerline until finding the installed position that delivers the best performance. This is a very time-consuming process, but it ensures that we not only choose the best cam design but also the best installed position. Idle quality and manifold vacuum play a very important role in the decision also. Since our engines are designed for street use, not racing, we need to make sure all these factors best fit our customers' needs."
Using a combination of SuperFlow and DTS engine dynos, BluePrint dyno tests every single engine that it builds to verify horsepower and torque output. Although hot rodders will naturally fixate on these figures, the dyno serves as the ultimate tool for ensuring quality control by simulating the operating conditions of a running engine as installed in a car. "We want to make sure that we can show our customers the power that their engine actually made. They are paying for that power and we want them to have the peace of mind that their engine is going to do what we say it will do," Chris Larson explains. "However, a lot more goes into a dyno session than extracting hp and torque numbers. Once we get the water and oil up to proper operating temperature, we set the idle rpm, ignition timing, and air/fuel ratio at idle and wide-open-throttle. To make sure that the engine is breaking in properly, we check the lifters to confirm that they are rotating and seating properly. Additionally, we check intake manifold vacuum, and run a dye through the oil system to check for leaks using a blacklight. By actually running every engine before it leaves our facility, it ensures that customers are getting the performance and reliability they expect from one of our engine packages. It really is the last quality checkpoint for an engine has before it ships out."
Pro Series engines
For those seeking maximum hp and durability, BluePrint recently introduced its top-of-the-line Pro Series engines. These offerings range from 427ci Gen I small-blocks with a stout 540 hp, to 632ci big-block monsters belting out 815 hp. Not surprisingly, Pro Series engines come packed with premium components. "Our original catalog of crate engines are based on seasoned blocks that have been bored, honed, decked, and align honed. These engines are very affordable and represent a great value," says Dru Freese. "However, we still had a lot of folks who wanted a new aftermarket block, which prompted us to develop our own unique block casting. Our BluePrint blocks boast thicker cylinder walls, taller deck heights, and additional clearance for stroker crankshafts. This allows building small-blocks as large as 454 cubic inches, and big-blocks as large as 632 cubic inches. Pro Series engines also feature hydraulic-roller valvetrains and forged rotating assemblies for the ultimate in durability."
To suit the diverse needs of a broad cross-section of hot rodders, BluePrint builds engines with both cast and forged rotating assemblies as well as engines with both flat-tappet and roller camshafts. Engines can also be configured with either iron or aluminum cylinder heads. Based on decades of experience building and developing engine packages, BluePrint has a firm grasp on when fancier parts are appropriate, and when they're overkill. "For a street small-block, cast cranks work fine up to 450 hp. On the other hand, if you're building a circle track engine at the same power level that spends much more of its time near peak power, I would start thinking about a forged crank," Chris Larson explains. "As far as cylinder heads are concerned, on lower horsepower engines up to 400 hp, an iron small-block Chevy Vortec head works very well. Once horsepower goals exceed the 450- to 500-horsepower range in small-blocks, aluminum heads really help. In regards to roller cams, they are all-around superior performers when it comes to durability. Since they can handle steeper cam lobes than flat-tappet lifters, they yield more area under the curve for a given duration, which increases power output while maintaining drivability."
Taking a product from concept to production is a tedious process that requires a tremendous amount of resources and time. According to BluePrint, everything it builds and manufactures is based on customer demand. In addition to listening to customer feedback, the company works very hard with its distributors to find out exactly what type of product customers would like to have in their vehicle. For example, BluePrint decided to get into block manufacturing because of the simple fact that it had a hard time finding suppliers with the parts that it needed in stock. "We attend multiple trade shows each year where we meet with thousands of hot rodders to find out more about what the market wants. From there, our marketing and engineering teams work together to develop those products with specific price points and power requirements in mind," says Dru Freese. "Next, we go to our design team and challenge them design an engine that meets our requirements and we also identify the components that will be needed. From there, we head out to our suppliers and work with them to develop a list of the exact parts needed to reach our target objectives. Designing a new product is not quick, but we always strive to end up with a solid design that can meet customers' needs at an affordable price."
When designing a new aftermarket block castings for big-block Chevys, BluePrint's goal was designing a product that met the needs of both its customers and engineers. Ultimately, BluePrint whipped up an all-new casting available in both standard 9.800- and tall 10.200-inch deck heights with extra thick cylinder walls that can accommodate a maximum bore of 4.600 inches. Depending on the bore diameter desired, these castings are available in siamesed-bore or full water jacket configurations. Other features include priority main oiling, four-bolt ductile-iron main caps, mechanical fuel pump provisions, an extra head bolt hole per cylinder, and compatibility with standard and tall-body lifters. "Our standard deck block is has enough clearance to accommodate a 4.375-inch stroke, and our tall-deck block can handle a 4.750-inch stroke for a total displacement potential of 632 cubic inches. BluePrint's blocks are available as standalone part numbers as well as in our crate engine packages," Dru clarifies.
The need to build crate engines that achieved very specific performance objectives prompted BluePrint to design its own line of cylinder heads for both small-blocks and big-blocks. The company's original cylinder head lineup included two as-cast heads for small-block Chevys and another two sets of as-cast heads for big-block Chevys. Since then, it has expanded to include CNC-ported variants as well as an all-new line of LS3 cylinder heads. More specifically, BluePrint offers 195- and 220cc as-cast heads for small-block Chevys, as well as large 210- and 235cc variants that are CNC ported. Big-block Chevy options include an as-cast 316cc head, in addition to 358cc castings available in as-cast and CNC ported configurations. Perhaps the company's most exciting new product is its all-new LS3 castings. Available in as-cast 259cc and CNC-ported 270cc models, these heads feature a revised valve angle that has been flattened from 15- to 11 degrees. "Although we rolled the valve angle, we retained the smaller LS3 valve diameter of 2.160 inches to maintain compatibility with smaller 4.000 inch bores. Other highlights include a thicker 0.750-inch deck, taller valve cover rails for additional valvetrain clearance, and compatibility with stock valvetrain hardware with exception of the valves and pushrods," Chris explains.
As with BluePrint's blocks, its cylinder head castings are available separately or as part of BluePrint's crate engines. Regardless of how they are ordered, quality control is always a top priority. "Our as-cast performance heads don't stray far from what's been the norm in the market place for years. We are constantly adding features that our customers ask for, and the quality that people have come to know us for. Likewise, for our CNC heads we work hand in hand with some of the best port designers in the country to optimize airflow. All of our CNC designs get validated on the engine dyno to prove that with the right combination if parts, they will produce significant power increases over our raw castings. Moreover, we perform a standard 20-point inspection on every cylinder head that goes out the door. We check the valveguides, seats, combustion chamber volume, valvespring pressure, and valve runout on every single casting we make."