April '20

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38 THE SHOP APRIL 2020 PRECISION ENGINE 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 ensured the stability of the vacuum hose, preventing any potential restrictions that might occur if the hose began to col- lapse 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 and 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- to 3/4-inch shy of each hose end). SMALL-BLOCK CHEVY JONES RACING VACUUM PUMP Two-stage vacuum pump VP-9100-C Pump bracket VP-9100-L-BM 38-tooth pulley FP-6106-38-5/8 38-tooth drive pulley BG-6108-38S Radius tooth belt 760-10HD Vacuum pump plumbing Earl's —12 hose 350612ERL 90-degree hose ends AT809112ERL (4) Weld-in fittings 997112ERL (2) Weld-in fill bung w/cap 166018ERL BIG-BLOCK CHEVY JONES RACING VACUUM PUMP SYSTEM COMPONENTS Two-stage billet vacuum pump VP-9100-C 36-tooth pump pulley BG06108-36S Drive hub DH-8101-B Hub mandrel 3.5" x 1.125" DHM-8101-B Drive hub spacer kit SP-6103-KP (one SP-6103-A-A 1/4"; one SP-6103-B-A 3/8"; three SP-6103-C-A 1/2") BBC lower VP bracket VP-9101-B Crank snout mandrel bolt/end cap/ washer…..(1/2" x 20 x 6" bolt) BEC-2109-L Two 1/8" keys for mandrel-mounted pulleys KS-2109-D Two 3/16" roll pins for drive hub RP-2109-C Drive pulley for vacuum pump CS-6102-AC-32 Two 3.5" OD x 1.125" ID belt guides BG-6108-C 31.496" x 10mm radius tooth belt 800-10HD 4-ft internal support coil to prevent the AN hoses from collapsing AN-1200-SC Two –12 weld-in aluminum male bungs (for valve covers) AN-1200-B One –12 weld-in female bung for oil fill port ANB-1200-FB One –12 male thread plug oil fill cap ANB-1200-P Breathe a Little Easier The crank snout-mounted drive hub as- sembly from Jones Racing allows mount- ing the drive pulleys for our alternator and vacuum pump. Note the aluminum spacers that allow fine-tuning for pulley alignment. The vacuum pump pulley is mounted to a shaft that registers on a long keyway groove, allowing you to adjust the fore/ aft pulley position for perfect alignment to the drive pulley. Three set screws lock the pump pulley in place, and Jones Racing provides access holes. As seen on this big-block Chevy example, plumbing the vacuum pump is very straightforward. The two –12 vacuum inlet ports (seen here) are plumbed to the valve covers. A single –12 exhaust port (located on the opposite side of the pump body) is plumbed to a remote breather.

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