Building A Big Arm Wedge-500 Inch Stroker - Long Arm Wedge

To correct the overly-tight piston-to-rod side clearance, the inside of each piston was machined 0.025 inch to provide the necessary side clearance. It's a good thing your knuckleheaded author didn't try to build this shortblock himself.

We began the final engine assembly by checking the ring endgaps. The special tool in Joe's left hand sets the rings dead square in the bore. In his right hand is a feeler gauge measuring the ring endgap. We used file-fit rings that were filed until the desired gap was obtained for each ring set (top, middle, and oil) per each cylinder.

After the rings were filed, their edges were deburred. A fine sanding stone was used. This was a tedious job, but it must be done. A burr on the rings' edge might cause the rings to hang up and ruin the ring land on the piston.

Crankshaft endplay measured 0.006 inch. It should not exceed 0.012 inch or measure under 0.002 inch, so we were in good shape. The Pro-Gram main caps were sequentially torqued, and the crank was spin-tested to be sure it would spin freely without any tight spots.

Each ring was cleaned with lacquer thinner after file-fitting and deburring. Look at the dirt accumulation on the rag from only one swipe. You don't want dirt or metal filings to scratch your freshly-honed cylinder walls. On the sidelines were the pistons awaiting their rings.

The piston, rings, and rod slid down the tapered ring compressor right into the appropriate cylinder. A thin coat of oil was applied to the piston, pin, rod, rings, and cylinder bore before installation.

Assembly lube was used on the rod bearings and ARP rod fasteners because dry threads on the fasteners can create inaccurate torque readings. We continued to spin-test the rotating assembly after torquing each rod to assure there was no binding.

Here's our balanced and blueprinted short-block. The piston-to-deck height measured 0.020 inch. A motor with proper clearances, geometry, and balance eliminates destructive vibration while producing more power.

The Edelbrock heads feature larger-than-stock 2.14/1.81 stainless steel valves. The dirty 2.08/1.74 valves came out of an old 906 head. We opted to use closed-chamber 84cc Edelbrock heads. Also available are 88cc open-chamber heads that lower the compression nearly half a point. Aluminum heads allow for a compression-ratio increase of one point over iron heads due to aluminum's heat-dissipating abilities.

The E-Brock head (left) shows off its larger 210cc intake and better flowing ports compared to the old 906 head with a 200cc intake. Stock 906 heads only flow 210 to 220 cfm at 0.500 to 0.600 inches of cam lift. Edelbrock heads typically flow about 270 at 0.500 lift and 280 at 0.600 inches of lift. The 30-year-old 906 castings would take too many hours of porting and larger valves, and they still wouldn't flow as well as Edelbrock heads. Also, aluminum heads lighten your car's nose by nearly 50 pounds, which means quicker weight transfer and launches.

Mike Barton flow-tested our heads before and after he did some mild porting work. We only blended the ports where the Edelbrock CNC bowl porting and gasket matching ended. The valveguide bosses were thinned, and the ports were cleaned with 100-grit sanding rolls to remove any casting flash. Mike back-cut the intake valves 28 degrees, which increased the low lift-flow numbers significantly.

The Edelbrock valvesprings are rated for up to 0.600 inches of cam lift. With the 0.638-lift solid cam that Ray chose for our combo, we had to change them. Here, Joe switched to the Comp Cams 929 double springs, leaving out the inner spring (for cam break-in). Holding the springs in place were Comp's 10-degree titanium retainers and superlocks.

After the installation of the cam and pushrods, the piston-to-valve clearance was checked (.095 int. and .145 exh.) and the cam was degreed to the cam card. Initial valve lash was set at .022. After the initial cam break-in, the inner valvesprings will be installed and the lash set to specs. With proper planning, this should easily be a pump-gas (94 octane), street-driven engine.

Milodon's new windage tray for stroker big-blocks was used for our buildup. We had to trim it for pickup-tube clearance. Also from Milodon were their popular 7-quart low-profile oil pan, pickup, high-volume oil pump, and oil-pump shaft.

Before we did any machining to the Mopar Performance M1 intake, we wanted to see how it would line up with the new Edelbrock heads. The black circle below the carb base is where a vacuum port will be drilled and tapped for power brakes. When building a big-block stroker motor, a single-plane intake has been proven the best choice.

The Mopar M1 intake is 1/4 inch higher than the Edelbrock RPM intake we used on our old 440. Here, Rob was in the middle of milling 0.200 inch off the carb base. We wanted the M1 to fit under the R/T's low hood with the Wilson 1-inch spacer. The Barton 440- or 500-inch engines-usually 446 or 493-come standard with your choice of Edelbrock's dual-plane RPM or the single-plane Victor. RBRE can hook you up with your intake of choice.