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The 1/4-inch x 20 x 3.5-inch socket head cap screws supplied with the Moroso valve covers are fine, and function perfectly. But, being the anal dolt that I am, I wanted to dress things up a bit more. I installed stainless-steel 1/4-inch x 20 x 4-inch studs into the heads (purchased from McMaster-Carr under P/N 95412A558), and then secured the valve covers with Cam Motion’s Top Seal blue anodized billet aluminum knurled hand knobs. I selected their short-hat version at 0.637 inches tall (they also offer tall-top models at 1.136 inches high). All of their knobs feature a 1.50-inch diameter knurled hand-knob. The knobs are offered with either 1/4-inch x 20 or 5/16-inch x 18 female threads.
Granted, these knobs are intended for air cleaner lid use and may appear a bit large in diameter for valve cover use, but they’re extremely functional, adding a bit of convenience for hand-servicing the valve covers. Although this setup may be totally unnecessary, I thought it looked cool and the quick no-tool servicing would definitely come in handy in the pits.
In order to provide an oil-fill location, I installed a Jones Racing weld-in -12 female bung to the roof of the left side valve cover to serve as an oil fill port. This is sealed with a Jones Racing screw-in aluminum plug that features an O.D. hex and a sealing O-ring. Since we’re using the Jones Racing vacuum pump system, the engine needs to be sealed, so a valve cover breather was a no-no. Installing the bung required cutting a 1 5/8-inch hole in the cover (8 7/8 inches from the front wall, inline with the second pair of valve cover bolt locations, in an area where I knew I’d have a clear shot for oil fill between rocker arm locations).
In addition, a -12 weld-in male fitting was needed on the front wall of each valve cover in order to plumb to the Jones Racing vacuum pump. For each valve cover, a 3/4-inch hole was drilled and the male weld-on fitting was surface-mounted to the valve cover wall and Tig welded around the perimeter of the fitting’s hex.
Saeco, a local fab shop in nearby Wadsworth, Ohio, performed the Tig
welding of all three fittings (since yours truly doesn’t own a Tig, and doesn’t know how to use it even if he had one).
VACUUM PUMP
Jones Racing supplied a vacuum pump system featuring its lightweight billet aluminum vacuum pump VP-9100C. This is a two-stage gear-style vacuum pump that runs at 50 percent of engine speed and pulls a constant 15 psi, providing enhanced piston ring seal. The negative pressure created by the pump results in less resistance on the pistons during the compression downstroke, resulting in faster piston acceleration. This constant vacuum also helps to draw parasitic oil from the rotating assembly (theoretically increasing power) and allows the oil pump to function with less resistance, which should increase oil flow.
I mounted the pump on the lower right engine side. In order to provide clearance for the water pump neck, Jones supplied an extension bracket that shares the two block mounting bolts for the crank trigger sensor bracket.
In order to provide a mounting for the crank pulleys (for both our vacuum pump and our Jones Racing alternator), we installed Jones’ DH-8101-B BBC drive hub and their DHM-8101-B (3.500 inches x 1.125 inches O.D.) mandrel. The drive hub (and the hollow mandrel) secure to the crank snout with a 1/2-inch x 20 x 6-inch bolt. In addition, to prevent the drive hub from rotating independently, the hub
features two 3/16 inch roll pins. This required drilling a pair of 0.190-inch holes in the face of the damper (on the recessed flat face that surrounds the crank snout). The roll pins were pressed into the drive hub and the roll pins engage into the holes drilled in the damper.
The drive hub mandrel threads into the drive hub (featuring a left-hand thread) and features a 1/8-inch keyway slot that runs the entire length of the mandrel.
Once I mocked up the crank snout pulley and spacer assembly for proper pulley
alignment to both the alternator and vacuum pump pulleys, I removed the pulleys and spacers. I installed a 0.250-inch-thick spacer against the drive hub, then installed a key for the alternator drive pulley. The alternator drive pulley and its guide plates were slipped on, followed by three aluminum spacer rings (one 3/8-inch and two 1/2-inch thick spacers), followed by the vacuum pump drive pulley, one 1/2-inch spacer and finally the billet aluminum nose cup, loc washer and the 1/2-inch x 20 x 6-inch crank snout bolt. The array of aluminum spacers (in various thicknesses) allows you to tune the spacing of the pulleys on the mandrel.
In order to achieve fine-tuning of the vacuum pump’s pulley to the pump’s drive pulley on the crank mandrel, by loosening three set screws in the pump’s pulley, you’re able to slide the pulley fore/aft on the pump’s shaft for perfect belt alignment. Once alignment is determined, tighten the set screws. Access holes in the pump pulley allow easy entry for a hex wrench for servicing the set screws.
Routing the plumbing for the vacuum pump was super-simple. I made a pair of -12 hose assemblies using 90-degree -12 hose ends at each end of the two hoses.
The two outlet ports on the pump are plumbed directly to the -12 male weld-in fittings on the front face of each valve cover. The single outlet (exhaust) port from the pump will be plumbed to a remote breather in the dyno shop. Assembly of the -AN hoses was straightforward, in terms of installing the hose ends to the hoses (by the way, I used swivel-type hose ends at the valve cover locations to enable easy clock-position adjustment for a precise hose-end-to-fitting alignment).
The only special step involved inserting a section of Jones Racing’s flat-wound internal support coil into each hose length. This ensures the stability of the vacuum hose, preventing any potential restriction that might occur if the hose began to collapse internally under vacuum.
Initially, this was the pain in the butt part of the job. The stainless steel support coil must be wound counterclockwise to minimize its diameter (bringing the coils together, forming a tube), and then push-fed into the hose, pretty much one to three coils at a time. I lubed the inside of the hose with engine oil to ease insertion, but this was time consuming and frustrating in the beginning until I developed the knack.
I installed one hose end, installed the support coil, then installed the second hose end. The internal support coil comes in a 4-foot length. I cut two pieces with a snip, one for each hose. I tailored the coil length to match the full hose length between the hose ends (with the ends of the coil about 1/2-3/4 inches shy of each hose end). By the time I finished installing the support coils in the two vacuum hoses, I had resurrected just about every cuss word in my vocabulary. Of course, after fitting these two hoses, I felt like a pro.
ALTERNATOR SETUP
I mounted the Jones Racing alternator on the left side, using the existing threaded holes on the block face. The Jones mounting bracket fit like a friggin’ glove and it’s pretty to boot. Belt adjustment is a breeze, thanks to a heim-joint-ended LH/RH thread hex body turnbuckle. This is without a doubt the best-fitting and easiest-to-install custom alternator setup I’ve ever had the pleasure to install. Jones offers a multitude of alternator bracket configurations (for high-mount, low-mount, LH, RH, etc.), but I really like this little bugger. This is a nice application for both race engines and street rod builds, offering both form and function that would please even the most finicky customer. Very pro.
Tags: ALTERNATOR, ASSEMBLY, JONES RACING, MOROSO, VACUUM PUMP, VALVE COVERS
