Are you holding onto your small-block Chevy with a death grip, not yet ready to make the jump to the LS world? You aren’t alone. Any weekend car show or staging lane at a dragstrip is testament to the Gen I small-block’s 21st century relevance. Despite the wave of excellently engineered LS engines, people just keep building small-block Chevys. Heck, so do we! They are fantastically affordable and simple engines with more aftermarket support than any other platform, bar none. However, since Ed Cole and Zora Arkus-Duntov penned the small-block in an unbelievable 15-week thrash of internal-combustion genius-ness, there have been countless improvements and innovations for the famed Mouse motor.
Just because you’ve decided to stick to a time-tested engine architecture doesn’t mean you have to build it the same way it left the factory. With the following simple build tips you can catapult a Mouse motor, originally penned with a slide rule in 1955, straight into the modern performance era.
1. Piston Oil Squirters
Many modern engines incorporate oil squirters, or jets, that feed a constant stream of pressurized oil onto the back of the pistons. This not only helps to cool the pistons, it also aids in lubrication of the wristpins and rings, especially at low rpm where oil splash is minimal. BLP Racing Products offers a retrofit kit for the small-block Chevy (as well as big-blocks and other engine platforms) that integrates an oil spraying jet into the base of each bearing saddle. The kit uses a simple jig with a long drill bit to locate the jets in the correct position. The kit is especially relevant for engines using nitrous or boost where cooling the piston becomes far more critical than in naturally aspirated applications.
2. Thinner and Gapless Piston Rings
Sometimes, bigger is not better. This is especially true in the world of piston rings, which seem to be perpetually shrinking. The standard ring thickness for the small-block Chevy was 5/64-inch top, 5/64-inch middle, and 3/16-inch bottom—sizes that hung around for the engine’s entire production run! With the introduction of the LS engine, Chevy instituted a thinner, metric ring pack of 1.5mm, 1.5mm, and 3.0mm, respectively. It didn’t take long for hot rodders everywhere to realize that thinner piston rings equated to more horsepower from less drag (friction) on the cylinder walls and better sealing from increased conformability. Taking the concept of improved cylinder sealing even further, Total Seal designed a gapless piston ring that utilizes two interlocking rings per groove with gaps set 180-degrees apart. This design minimizes blow-by, and we’ve seen these rings be worth significant power on the engine dyno. Lastly, adding thinner rings doesn’t necessarily mean buying new pistons. Total Seal offers a line of piston-ring spacers that allow a 1.2mm ring to slip into a 5/64-inch ring groove.
3. Bi-Metal Bearings
If you plan to have your small-block on the road for years to come, adding bi-metal bearings during your build is a smart move. This style of bearing, which is composed of a silicon-aluminum alloy overlaid on a steel backing, is much more durable than conventional tri-metal bearings. The silicone makes the bearing harder—often harder than the crank itself—and will allow the bearing to last significantly longer. Manufacturers made a move to this style of bearing in the mid ’90s and they have been proven to last well into the 150,000-mile range as long as the oiling system is kept clean. They are the factory-issued bearings in LS powerplants. Several of the major bearing companies, such as Mahle Clevite, offer this formula of bearing for the small-block. However, it is important to point out that these bearings aren’t designed for use in purpose-built race engines and it is better to stick with a tri-metal bearing because of their greater load-carrying ability.
4. Stroker Crankshafts
Cubes are power, and the best weapon in any hot-rodder’s arsenal is displacement. The aftermarket is rife with excellently designed stroker cranks, such as this Scat piece that can bump your small-block up to the next pant size. Not only are Gen I small-block stroker cranks plentiful in all materials and strokes, they are also some of the most affordable of any engine architecture, ever. A brand-new, cast-steel stroker crank can be purchased for under $200—which begs the question, “Why reuse a stock crank when extra cubic inches are only a few cents away?”
5. Hypereutectic Pistons
There is a lot more to piston design than “cast or forged.” Today’s piston manufacturers reap the benefit of greatly improved alloys suited for all manner of performance applications. The style that has dominated the OEM market, hypereutectic, is right at home in Gen I small-blocks. It is an excellent upgrade in mild-to-moderate performance applications. Hypereutectic pistons are made by casting aluminum that is oversaturated with silicon. The addition of silicon makes the pistons stronger and more thermally stable. Because they expand less with heat they can be run tighter in the cylinder bore, some as tight as 0.001-0.002-inches. By decreasing piston-to-wall clearance, the cylinder walls have better wear characteristics, the rings seal better, and the pistons take less of a beating during cold starts. Nearly all LS engines, save for some of the factory-supercharged variants use pistons of this material.
6. Fuel Injection
It’s no secret that fuel injection possesses some distinct and poignant advantages over a traditional carburetor, such as better cold-starting, increased fuel economy, and altitude adaptability. There are a plethora of aftermarket systems on the market, ranging from wild laptop tunable systems ready to take on any horsepower level you can dream up, to self-learning carburetor-replacement-style units that will make your classic engine even more fun to cruise. We’ve had a blast learning fuel injection these last couple of months and there’s a good chance that once you make the switch, you won’t be going back.
7. Roller Camshafts
Unless you’ve spent significant time under a rock in the last five years, you know that roller camshafts are a worthwhile investment in any pushrod engine. They increase durability (especially with modern, zinc-free oils) and also offer more aggressive ramp rates to open and close the valve faster. This “area under the curve,” the amount of time the valve is at, or near, peak lift allows more air to flow into the cylinder increasing horsepower and torque. In last month’s issue, we found that installing a Comp Cams roller cam in an SBC with the exact same duration as the outgoing flat tappet to be worth 14 horsepower on an otherwise unchanged engine. With larger cams, even greater results are possible.
8. Hotter Ignition Systems
If you’re still using points ignition, you better dial up an ignition company on your rotary phone and purchase something from this century—fast! Modern ignition systems such as Performance Distributors HEI units or ignition-box-based systems from companies such as MSD offer vastly hotter spark energy that better ignites the fuel in the combustion chamber. Many of these systems even offer engine-protecting rev-limiters. Others even have the ability to plot out your ignition-timing curve digitally and can make instant timing adjustments based on boost or nitrous. In addition to peak horsepower improvements, a modern ignition system aids in both cold- and hot-starting and can even improve fuel economy.
9. Aluminum Cylinder Heads
Cylinder head technology has made leaps and bounds in the small-block’s half-century lifetime. Gone are the days of scouring swap meets and junkyards for “camel hump” heads. The aftermarket is absolutely filled with quality aluminum head castings. These AFR 195cc Eliminator Street heads, pictured, offer a serious horsepower bump over even the best factory iron heads. Bigger valves, sculpted ports, and finessed combustion chambers all aid in cylinder filling while the aluminum alloy allows engines to be built with more compression, without the risk of detonation. Again, the small-block Chevy has the market cornered on the most affordable heads.
10. Forced Induction
There was a time when forced induction was practically military-grade technology, and only a few hot rodders had cracked the necessary codes to get it installed and properly tuned on their cars. In today’s day and age, installing a supercharger or turbo kit on a car, whether you have a carburetor or EFI, has become no more difficult than a cam swap. And, when it comes to adding boost, the Gen I small-block has many things going for it, such as five headbolts per cylinder and a plethora of off-the-shelf pistons with boost-friendly compression ratios. Couple those things with advances in head gasket technology, such as the multi-layer steel (MLS) gaskets that are now the industry standard, and you are ready to make big power numbers without breaking a sweat.