December 2012 Chevy High Performance Q&A

Totally Broke(n)

Kevin McClelland Oct 22, 2012 0 Comment(s)

Hopefully, this has given you some ideas and direction building a great crate for your SS. Either of these packages will have no problem passing the California emissions test-only program. You can expect the 350 package listed above to produce around 330-340 hp with your Edelbrock inlet, T.E.S., and Hypertech chip. The 383 will knock down 350-360 with well over 400 lb-ft of torque to plant you in the seat. Have fun choosing and enjoy your Monte.

Sources: chevroletperformance.com, dartheads.com, edelbrock.com

Belted In

Q. My alternator/water pump belt keeps coming off. This is a street/strip ’68 Camaro, with a 383ci small-block, F-1R ProCharger, and five-speed (GF5R shifted without the clutch at 7,000 rpm), and has run 9.0s at 12748 mph and 7,200 rpm. I have spent many hours making sure the pulleys are in alignment; everything looks great, then about 100 miles and 12 runs later the belt comes off. It is always twisted and sometimes takes out the 12-rib blower belt with it. I always replace it with a new high-quality belt, most recently a Napa Premium PN 25-7445, 13/32x45 1/8 inch.

I am using ProCharger powdercoated aluminum pulleys, a 6.75-inch crank pulley, a 6.5-inch water pump, a 3.5-inch od alternator, and all are 0.5-inch deep. The water pump is a Weiand, long shaft and is tight with a Flex-a-lite 18-inch fan, which never gets hot. I’m running an MSD 130-amp alternator installed on the right head, stock location and hardware install for use with a long water pump. Please help if you can, as this really screws up a nice cruise night!

Bill Unruh
Riverside, CA

A. Beautiful Camaro, Bill! This car was featured in the Feb. ’09 issue of CHP. You have spared no expense building one very trick, very fast Camaro.

From everything we can find, MSD has gotten out of the alternator business, but here’s some very interesting technical information. The production V-belt pulley measures out at 2.64 inches od. The V-groove is machined to accept a 0.468-inch-wide V-belt. Your 13/32-inch belt width is right in there at the proper width for these pulleys at 0.406 inch. Yes, we’ve seen that even with proper alignment the belts can flip at high engine speeds and, soon after, leave their respective grooves. GM had the same problem with the early Z/28s when engine speeds went north of 7,000 rpm with the 302 engines. It remedied this problem with a very deep-groove alternator pulley, and the Corvettes also had deep-groove water pump and crankshaft pulleys. You can try and install a larger-alternator-diameter, deep-groove pulley and see if that takes care of the problem. Or you can convert the water pump, alternator, and crankshaft over to a six-groove serpentine beltdrive. The easy test is to install a Powermaster deep-groove pulley (PN 182). This pulley specs out at 4 inches od and has the unique 0.668-inch alternator shaft diameter. This is quite a unique spec for the shaft that MSD used. We would go this route first and give it a go.

As for the serpentine conversion, we’d recommend checking out what ProCharger has to offer. We’re sure you could pick up a set of pulleys from March Performance but we’re not sure how that would impact your blower drive. Good luck keeping the belt on your charger, alternator that is. It’s really no fun when you lose your only accessory belt!

Sources: marchperf.com, msdignition.com,powermasterperformance.com

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