Our last trip to the dyno was cut short when we scorched some pushrod ends due to a lack of lubrication. We had been using spray bars in the valve covers to provide lubrication to the Jesel rocker arms, but that setup didn't work correctly and several pushrods were ruined. An excellent solution to this problem is to use pushrod oiling, but in order to do that you need roller lifters that provide oil to the pushrods. There are roller lifters available for big-block Mopar engines which are capable of pushrod oiling, but as we found out, several of the lifters on the market do not work in an unbushed production block. The lifter bores in a big-block Mopar intersect the main oil galley, so each lifter bore is exposed to full oil pressure and volume. Because of that, roller lifters for a big-block have to be designed correctly, or else too much oil will flow through the lifters. After a little research, we discovered that the guys at Indio Motor and Machine (IMM) had a new roller lifter, which is capable of pushrod oiling in an unbushed block. These lifters also have an internal oil passage that provides high pressure oil to the roller's wheel, and they are available with a .180-inch offset pushrod cup if one needs that feature.

To go along with the new lifters, we needed a new set of pushrods with oiling holes. A quick call to Smith Bros netted us a set of .120-inch thick-wall pushrods that have a 3/8-inch outer diameter, and are 9.625 inches long. The IMM lifters require a 5/32-inch radius ball-end, while our Jesel rocker arms require a 9/64-inch radius cup-end.

Intake and Heads

Edelbrock recently introduced two Super Victor intakes for the RB motor, part number 2891 for standard port heads, and part number 2893 for the larger Max Wedge sized ports. For this motor we needed the version with the larger runners since our Indy EZ heads have Max Wedge ports. The Super Victor intake is designed for the larger 4500 flange carburetors, which was perfect for us since we prefer to use our Holley UltraHP Dominator when testing Max Wedge heads. We installed the intake manifold right out of the box without performing any cleanup grinding or port matching. No doubt a little bit of port matching and plenum work on this intake would pick up some power, so that is an area for future attention.

Before this round of testing, we sent the cylinder heads back east to our buddy Dwayne Porter at Porter Racing Heads in South Burlington, Vermont. Dwayne gave our EZ's a quick tune-up and a flow check on his bench. The heads checked out fairly well on his bench where they measured 362 cfm of flow on the intakes at .700-inch lift. The exhaust flow on these EZ heads is held back a bit by the stock port location, so it only runs about 66-percent of the intake flow. Even given the less than optimal exhaust flow, the EZ heads are no slouch in the power department when matched with the correct camshaft design.

Carburetor

Our Holley Ultra HP Dominator has performed great for us since we first got it, but when we came across the fully tunable metering blocks that BLP is making for the Dominator we decided to give them a try. These 5120 series metering blocks have jets in each of the fuel circuits so the engine builder can quickly make adjustments to the fuel curve. In addition to the jets in the fuel circuits, the BLP metering blocks have been redesigned so that the idle circuit is divorced from the main circuit. The separation of the idle circuit from the main circuit provides the main circuit with additional fuel flow capacity for large engines that make a lot of power. While we didn't necessarily need the extra fuel flow for this engine, we wanted to get a baseline established with these new BLP metering blocks for future projects down the road.