Q777 Supercharged Cobra - Blower brackets

Mounting the blower.

Once I had decided on supercharging, it never really crossed my mind that I might choose a centrifugal blower manufacturer other than Vortech. Sure, I know of 5 or 6 other brands, but I can't really see them competing with Vortech as far as product quality, reputation and great customer tech advice and service. On a number of occasions, I sent tech questions to Vortech. I had a folder full of information off these guys before I had even spent a cent with them!

When I received the supercharger and Ross and I sat it in the engine bay, a number of potential problems were revealed. First, the crank pulley is a one piece unit that has both the serpentine pulley to rotate the water pump and alternator, and the cog drive to turn the blower. This pulley was nowhere near lining up with where the blower pulley was sitting, so fabricator extraodinaire Ross whipped up a billet crank pulley spacer. This is a split design, with the Motec crank trigger wheel located within the spacer. By clamping the trigger wheel within the spacer rather than simply bolting it to the balancer, the spacer can be loosened to allow infinite adjustment of the trigger wheel. The Motec can compensate for these changes anyway, via the CRIP value (CRank Index Position) but you can never have too many options!

Ross had already made the alternator brackets to keep the alternator as close to the cylinder heads as possible. This was the key to keeping all the spacers as shallow as possible. From here, the blower bracket was drawn up and a trial copy was cut out of 1/2" thick wood. This helped in getting the location and depth of all the spacers that Ross turned up out of billet steel that mount to the water pump and cylinder head. The idler pulley was part of the ASP cog pulley set that I originally bought, and the spacers and washers for these were also turned up by Ross out of billet.

Vortech note that the V7 YS supercharger consumes around 130hp through pumping and frictional losses. That equates to an awful lot of load on the front crankshaft bearings. To significantly reduce that load, Ross went ahead and made his own crank/blower brace. At cranking speed, we determined that the blower moved about .006" towards the crankshaft. By simply installing the brace, and with no preload, we reduced that to .0015". Who knows how far the blower might have moved at 7,000rpm.... With the combination of rigid brackets and the brace, I can be sure that I'll never have belt alignment problems. After Ross had finished on the CNC machine, lathes and milling machines, I had the most impressive little box of billet masterpieces!!! It almost seemed a shame to bolt them onto an engine. The plate that locates the bearing on the crank pulley is fitted by countersunk fasteners that screw into the crank pulley. This was a tight fit, but we were able to tap a thread into the mounting face of the pulley. The plate has a lip that firmly locates against the inside of the crank pulley.

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