Power-adders are fun, they can turn any vehicle into a rowdy ride. If you’re trying to make serious horsepower, a power-adder will find the weak links in your engine in a hurry, including the block itself. The solution for those trying to make big horsepower when a turbo, supercharger, or lots of nitrous is being used is a billet aluminum engine block.

Billet blocks used to only be reserved for the most extreme engine combinations known to man, but these days you can find them in high-horsepower street cars. These billet beasts start out as 490-pound blocks of aluminum before they’re whittled down to 100-pound works of art. In this article, we talk with Ben Mens from Energy Manufacturing to learn why billet blocks are the best foundation for high-horsepower engines that use a power-adder.

Billet Block Basics

Billet engine blocks, like the ones Energy Manufacturing produces, are made from forged billet 6061-T6 aluminum. This is an extremely strong alloy of aluminum, and that strength is enhanced when the semi-finished blocks are heat-treated to T6 standards before they’re cryogenically stress-relieved. All of this is done to ensure the engine block will maintain its structural integrity no matter how much horsepower is being generated.

Non-billet engine blocks are created through a casting process. This means the base material the block is made from is heated until it becomes molten. That molten metal is then poured into a sand casting to form the engine block. While this method is great for producing many engine blocks quickly and for a good price, the structure won’t be as strong as something made from forged billet aluminum.

“The billet aluminum is going to be purer and have a superior grain structure over a cast block. That cast block material is made from several different alloys, and it’s going to have more impurities in it versus a billet material. The grain structure of the billet block is going to remove the impurities out of the equation, and that’s what makes them so strong,” Mens explains.

Since billet blocks are made from scratch they’re highly customizable. You will have a variety of deck heights available off the shelf, or you can even have a custom deck height created for your application. These blocks can have the cam location and size configured to meet your needs. You can even have the head studs moved around for a specific set of heads you want to use. If you can dream it up, chances are, an engineer can design a billet block that will fit what you’re trying to do.

Advantages Of Billet Blocks With Power-Adders

When you start to tickle the 2,000-plus horsepower range with a power-adder, that’s when you’ll want to start to explore moving to a billet block. At this power level, the strength of a cast block might not be able to keep up with the stress, and its longevity will start to suffer. Cast blocks with water jackets are really going to be at risk of failure at these power levels as well.

Pushing an engine package with a power-adder is a risky endeavor no matter what parts you use or how much tuning knowledge you have. These engines are being put through the wringer, and there’s a good chance you could hurt the block.

“If you have a cast iron block and hurt it, that block is pretty much done, you really can’t fix them. A cast aluminum block can be fixed, but it will never be the same again. Reheat treating an aluminum casing would certainly introduce some dimensional altering that would need to be addressed with additional machining that may or may not be acceptable. With a billet block, as long as you don’t saw it in half, it can be fixed. The billet block will have some scars from the repair, but it will be just as strong as it ever was. When you repair the billet block, a special welding process and welding rod is used that allows it to keep its strength. As long as the repair is completed correctly, no major machining is required. This is a big selling point and helps some people justify the additional cost of one of these blocks,” Mens says.

There’s only so many deck heights available with off-the-shelf cast engine blocks. When you’re reaching for the stars with horsepower goals, you need to be able to maximize and optimize every aspect of the engine, including the deck height. Billet blocks are going to open the doors of what deck heights are available for your engine build.

Billet blocks are the standard for high-horsepower engines that use a power-adder. The blocks are able to maintain their structural integrity in the face of all the stress a power-adder will produce.

“Another big advantage of a billet block in a power-adder application is the increased deck heights that can be used. When you have a taller deck height, it allows you to raise the position of the camshaft. Once you do that, then you can put more stroke in the crankcase. That extra stroke allows you to have longer connecting rods and pistons,” Mens states.

The increased strength that a billet block provides will allow an engine with a power-adder to really stretch its legs. You can also use the deck height options to your advantage, and match the power curve of your particular power-adder. Thanks to the taller deck height and stronger parts, the engine can be pushed to a higher RPM level, more than what a cast engine block could withstand. That’s where the advantage of a custom, taller deck height comes in, stronger parts can be used.

It doesn’t matter if you’re trying to force large quantities of boosted air into an engine, or feeding it lots of nitrous, the increased stress from a power-adder is going to test an engine block. The billet block is ready to deal with all of that additional stress and not have any integrity issues.

“A billet block is designed to deal with the pressure and stress a power-adder brings to the table. The cylinder bores aren’t going to move around, and that helps the rings maintain their seal. Its cam and crank bores are going to stay in line. A billet block starts out as a solid piece of material. A cast block is made when you pour material into a sand casting and there could be voids or other imperfections. That’s what makes billet blocks work so well with power-adders, they maintain their integrity well beyond what a cast block ever could,” Mens explains.

The mains on billet blocks are another area where strength is greatly increased. This additional strength helps them deal with extreme levels of horsepower that a power-adder can generate. 

“The mains aren’t going to do anything they shouldn’t as you increase the horsepower. We use 7075 billet aluminum to manufacture our main caps. This is the same material used in our nitro fuel race blocks. We have premium strength fasteners, and we increase the size as well of the fasteners. Our LS platform block uses 4-bolt 1/2-inch diameter vertical fasteners with 7/16-inch horizontal fasteners. Our BBC platform uses 9/16-inch (170 ft lbs torque) vertical fasteners with ½-inch splayed fasteners in all five main cap positions. Our SBF platform block uses the same size 9/16-inch fasteners and ½-inch outer fasteners with the center 3 main caps splayed and the #1 & #5 cap fasteners being vertical,” Mens states.

Power-adders have continued to evolve and grow stronger, so it’s only natural that engine block technology has to match that pace. Mens and Energy Manufacturing pays close attention to what racers are doing to ensure they stay one step ahead of what customers could ask for in the future.

If you’re going to build a max effort power-adder engine, a billet block had better be on your shopping list.

“An aftermarket cast iron or aluminum block is going to cost at least $3,000, and that’s before you have any machine work done. We put a lot of effort into creating billet blocks that are delivered and ready to go. Now, these blocks are going to cost significantly more, but they’re more advanced, stronger, and are going to last much longer. The billet block is also going work if you start adding more horsepower, or move to a different power-adder,” Mens says.

One thing is for sure, racers are always going to want more horsepower. A billet block is a solid investment for someone who plans on trying to make a lot of horsepower with a power-adder. The additional strength and durability the block provides are worth the added cost.