How To Increase Horsepower - You Can Build It!

Before hanging the rods on the pistons, it’s a good idea to make sure the piston valve reliefs are oriented correctly for the cylinder in which they will be installed. The big ends of rods are chamfered on both sides, but the side with larger chamfer must face the crank counterweight.

After sliding the wristpin through the piston and rod, snap ring pliers are required to secure everything in place. With piston pins that use spiral locks, the locks must be unwound, then slowly spiraled into position with a small flathead screwdriver.

As the pistons and rods travel up toward TDC in a stroker motor, it’s not uncommon for the rods to hit the cam. To prevent this, many aftermarket rods have profiled shoulders that offer additional clearance.

As with the main bearings, rod bearings also have tabs that help locate them in the big end. When installed correctly, both the tabs should be on the same side of the rod. For street/strip motors 0.0025 to 0.0035 inch of rod clearance is common.

Prior to assembly, Smeding thoroughly cleans all wear surfaces and wipes them down with WD-40. When installing the rotating hardware, assembly lube is used liberally on the main and rod journals. Oil is then squirted down each bore before installing the pistons.

Next, using a ring compressor and the small end of a mallet, the piston and rod assembly are installed into each bore. Smeding holds the rod end of the assembly by hand to prevent it from inadvertently gouging the cylinder wall.

Rod bolts can either be torqued down to spec, or installed using a bolt stretch gauge. This is also a good time to check rod side clearance with a feeler gauged. Anywhere from 0.010 to 0.015 inch is acceptable for a street/strip engine.

When installing the oil pump on the Number 5 main cap, it may be necessary to enlarge the locating holes slightly to get them to slide over the dowels. It’s important to pay close attention to the pump driveshaft to make sure that the tang slides into the oil pump groove.

The crank gear has a slot that locates it onto the crankshaft snout keyway. Since it’s an interference fit, beating the gear onto the snout with a hammer isn’t advisable. Smeding uses a brass sleeve and hammer to tap the crank gear into place.

With the timing set and cover installed, Smeding mocks the oil pan onto the block without the gasket, then rotates the motor over by hand to check for any potential clearance issues. Eliminating the gasket in this step makes clearance problems more obvious, and therefore easier to detect. Maintaining 0.250 inch of clearance between the oil pump pickup and pan ensures proper oil flow. After the clearance checks out, Smeding lays down RTV on both sides of the gasket around the timing set, then bolts down the pan.

Piston deck height is a measure of how far above or below the top of the piston rests in relation to the deck surface at TDC. It must be measured with a deck clearance gauge to accurately calculate the compression ratio.

Degreeing a cam is a quick way of ensuring that the camshaft is within specification, and phased properly in the motor. Smeding advanced the cam in this 572 by 2 degrees.

At this point, the assembly of the short-block is complete. After installing the lifters and head gaskets, it’s time to move onto the top end.

When installing the cylinder heads, they must be torqued down using a sequence specific to small- or big-blocks. Smeding uses AFR’s 325cc castings on its 572 crate motors, which flow a very impressive 384 cfm. They’re outstanding performers in street/strip applications, whereas anything larger is better suited for higher-rpm applications. On Gen I small-blocks, 200cc and smaller heads generally work very well in mild street/strip combos. Going any bigger in port volume requires a commitment to wind out a motor past 7,000 rpm, or building a 400ci-plus short-block.

After installing the pushrods and rocker, and lashing the valves, Smeding lays down the intake manifold gaskets and a bead of RTV on the front and back of the block, between the heads. Running a bead of RTV around the coolant passages helps seal the cylinder heads as well.

With the hard work out of the way, bolting the Edelbrock Victor Jr. intake and Quick Fuel Technology 950-cfm carb is cake. Smeding rates this beastly 572 at 690 hp and 700 lb-ft of torque. Complete with a three-year, unlimited-mile warranty, it costs a very reasonable $13,000. CHP