Comp Cams has recently introduced a new tool-steel valvespring retainer that has some very nice features, so we wanted to give them a try as well. The unique shape and material of these new retainers results in a very lightweight design when compared to previous steel retainers. The retainers, which we used, were PN 1732-16 and they only weighed 22 grams each. This is within a couple grams of what titanium retainers weigh, but these tool-steel retainers are significantly less expensive than titanium. Not only are these retainers lightweight and relatively inexpensive, but the thin design provides a lot more clearance to the rocker arm. That is a win, win solution which is hard to beat.
For this buildup we went with a set of stainless steel rocker arms from Rocker Arm Specialist (RAS). These rocker arms aren't very well known in the Mopar world but they are a great product that we have used for many years in different project engines. The RAS rocker arms come complete with heavy-duty shafts and hold-downs, as well as high quality adjuster hardware. The stainless rocker arms have a roller tip and a bronze bushing for the shaft. They are an excellent choice for a street roller since they'll handle the high forces of a roller cam valvetrain and they have the ability to live for a long time on the street.
Intake And Carb
Edelbrock recently introduced two Super Victor intakes for the RB motor, PN 2891 for standard port heads and PN 2893 for the larger Max Wedge sized ports. For this motor we needed the 2891 with the smaller runners since our Mancini Racing heads had the smaller, standard-sized ports. The difference between the Victor 440 and the new Super Victor intake is that the Super Victor is slightly taller with a larger plenum that is designed for a Dominator carb.
The Super Victor intake weighs 14 pounds, and is quite tall with a pad height of 6.350 inches. That height is about .250 inches taller than the Victor 440, which is a fairly tall intake itself. The carburetor mounting flange is not angled on this intake since most race engines are installed fairly level in the chassis. The runners are about 7 inches long, which is fairly long for a single plane intake manifold. The carb flange is a modified cloverleaf design which might not mate up with most carb spacers, but that should be easy to fix with a grinder.
The fit and finish of this intake was very nice, so we didn't do anything other than bolt it on our engine right out of the box. The Super Victor is tall enough that you can peer down the runners from the plenum and see into the ports in the cylinder head. A close inspection showed that we did not have a perfect port match between the runners and the head ports right out of the box, but they looked close enough so we ran it untouched.
Our Holley Ultra HP Dominator has performed great during the last series of tests we conducted, so we just adjusted the jet size and bolted it back on this motor. We reduced the main jets by four sizes in order to lean out the carb to work with the smaller runners in the Super Victor intake, and then we were ready to go.
On The Dyno
The first order of business on the dyno was to check the cranking compression. We always check the cranking compression on new combinations in order to give us a baseline that we can keep track of over time. We considered it a good omen when all eight cylinders cranked right at 200 psi with very little variation between them. Our plan was to run all tests with the ignition timing locked in at 37 degrees of advance, so we played it safe and used race gas. It is possible to get by with pump gas at 200 psi of cranking compression, but we didn't want to push our luck during these tests since we knew we would be thrashing the engine.
We used the large-bore FelPro...
We used the large-bore FelPro 1105 head gaskets in order to make sure that there wasn't any part of the head gasket overhanging the combustion chamber. These 1105 head gaskets work with 4.500-inch bores, so it was bigger than what we needed on the cylinder side, but we needed the extra clearance around the intake valve on the head side.
The newest retainers from...
The newest retainers from Comp Cams are made from high strength tool-steel. Due to their strength, they have a unique shape, because they can be thinner and lighter than the usual steel retainer. These steel retainers are only two grams heavier than a titanium retainer but they cost a lot less.
We dialed in the Comp camshaft...
We dialed in the Comp camshaft by using a large Moroso degree wheel and a custom dial indicator holder. This setup allows us to check both the exhaust and the intake centerlines with just one setup.
We installed the camshaft...
We installed the camshaft with 2 degrees of advance. The Jesel belt-drive system allows for very quick and precise cam timing. This arrangement sure beats messing around with offset dowel bushings. Again, it's overkill for the street, but during dyno sessions, it makes it easier to test different timing choices of the camshaft.
The front of the motor is...
The front of the motor is a little busy with the MSD crank trigger, the Jesel belt drive, the Meziere reverse flow water pump, and the Jesel front mount distributor. These parts all work together to provide us with rock steady ignition and cam timing. Sure, it's a bit much for a street engine, but its durability and consistency removes any variables during dyno testing.
A side-by-side view shows...
A side-by-side view shows some differences between the Super Victor intake and the slightly shorter M1 intake. The M1 intake has a square plenum area and shorter runners. We didn't see much difference in power output between the different manifolds on this particular engine combination, but your results might vary.
Now that we've pulled the...
Now that we've pulled the 505 off the dyno, maybe we should put it in a car and really give it a thrash. With over 600 lb/ft of torque and 680 hp, it should be a fun day at the track.