As if the bottom end of this baby Olds didn't already have our heads spinning, looking at what was bolted on top of the block blew our minds. With an amount of consideration and effort that would make a Super-Stocker look like a bracket racer, Dale transformed the ordinary 5A casting heads into fully functional race heads. On the exhaust side, the center two cylinders share a common port, a terrible design for anyone wanting to make power. Using a block of iron to fill the main gap in between the two adjoining cylinders, Dale spray-welded iron to fill the remainder of the gap as well as to raise the floor of the exhaust port by almost a half inch. Similar treatment was given to the intake side as the floor was raised there by about 3/8 inch with epoxy instead of the spray-weld. "I've got about 10 pounds of epoxy in that motor between the heads and the intake manifold." Knowing he wouldn't need enormous runners for the amount of cubes, Dale kept the volume down. He says: "The intake port is way smaller than the original. I think the factory was 152 cc and now it's down to 145 and it's much higher. It's got a small cross section of 1.9 [square inches]." Final flow numbers ended up around 195 cfm on the intake and 170 on the exhaust. Though not huge peak flow numbers, he claims they were almost at those numbers by .200-inch lift. Just perfect for limited camshaft and rpm range applications.
Using experience and catalogs as his guides, Dale was able to round up a set of small-block Chevy 2.02-inch intake valves and 1.60-inch exhaust valves that he cut down to 1.55 inches, profiled, and back-cut. Both used lightweight 5/16-inch stems to reduce the amount of mass that the COMP Cams beehive springs would have to control. When determining the required spring pressure, this was their first solid flat-tappet engine build, so they took a stab at it and set it up with 130 pounds on the seat. But Dale says: "After looking at what everybody else used, I think I could have gotten away with less. Maybe I could have freed up some horsepower in the block then."
Having a set of T&D 1.65 rockers already on hand gave the Robinson Analytical team a head start, and they just bought a set of 1.8 rockers to swap onto the shafts for the intake side. Rocker arm geometry was right on the money as the roller tip sat directly in the middle of the valve with almost no movement.
Between the more-than-stock heads sat an equally modified Edelbrock Performer RPM intake manifold. Originally designed for a spread-bore carb like the factory Q-Jet, the manifold carb flange and portions of the runners were filled with epoxy to better fit the Edelbrock Thunder AVS square-bore carb and match the raised runners in the heads.
Once the Robinson Analytical team had their engine together it was time for testing. Normally a simple procedure for the Chevy and Ford guys, Dale says: "It was the first time we ever had an engine on the dyno and it was kind of a scramble. First of all, they didn't have an Olds bellhousing, we had to cobble up a Chevy one. Then we couldn't get it to butt up against the bellhousing. It's an old Superflow setup for a manual transmission crankshaft, and mine's an automatic crankshaft. So it took me an hour in the dyno room to grind a hole in the back of my crank to fit it up against." Once it got all lined up and fired, some basic timing changes and rod changes in the Edelbrock carb got the Olds where they wanted it.
Originally designed for the...
Originally designed for the spread-bore Quadrajet, this Edelbrock Performer RPM intake manifold was the recipient of a heavy dose of epoxy to reshape the plenum and make it fit the square-bore carb.
The remainder of Dale's investment...
The remainder of Dale's investment in epoxy went to the floors and walls of the intake runners. Raising the runners 3/8 inch and moving them over slightly gave the air and fuel a direct shot down the throat of the port and into the chamber.
The valves the Robinsons picked...
The valves the Robinsons picked up were from a (jealous) Super Stock racer, and were back-cut and radiused before being combined with the COMP Cams Beehive springs and titanium retainers. COMP also supplied the 8.500-inch pushrods motivating the T&D shaft rockers. A look at how the exhaust stacked up behind the header gasket is another indicator of how much those exhaust ports were raised.