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Old 01-22-2018, 10:44 AM
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520SC 520SC is offline
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Join Date: Feb 2017
Location: Ewa Beach, HI
Cobra Make, Engine: 1966 Street Beasts Cobra 427 S/C, 502 cid
Posts: 121
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Way back in the day, I had a stock 1985 Camaro Z28 with a carbureted LG4 305 cid engine. I wasn't at all impressed with the performance of the car, so I ordered a crate 350 from Racing Head Service (RHS) -- a relatively inexpensive engine with a cast crank, 8.5:1 cast pistons, stock rods, cast iron heads with 1.94"/1.50" valves, Comp Cams 280 Magnum camshaft. I installed headers and dual exhaust, and a 172 cid B&M roots blower setup and Holley 650 carburetor (almost identical to the Weiand blower setup seen in the Engine Masters video shown above). The small roots blower was easy to install. The assembly stayed completely out of the way of the other accessories. The blower drive pulley was simply bolted onto the crankshaft in front of the existing accessory drive pulley. Intake manifold and carb installation were fairly simple, but there were two issues that I had to deal with in order to complete the installation. 1) The carburetor linkage had to be modified because the carburetor sat higher in the engine compartment. 2) I had to cut a hole in the hood because of the added height of the blower, about 6 inches.

A centrifugal blower would solve the height problem by placing the blower pump to the side, however, as mentioned in the video, there are some significant added expenses involved (e.g., the need for a blow-through carburetor, and a boost calibrated fuel system, possibly with the addition of a high pressure electric fuel pump). And then there's the issue of interference with accessories like the alternator and power steering pump, etc. It appears that centrifugal supercharger kits come with one-piece crankshaft pulleys, meaning that you'll have to obtain a pulley that has the correct belt types in the correct places to run all the accessories.

Overall, it seems like a roots-type blower is cheaper and easier. And now there's a more efficient version, the screw-type compressor made by Eaton. Those make more power with less heat than the old style blowers because they don't beat up the air as much while compressing it.

It'll be a tough decision. I really like the look of a blower sitting atop the engine, but I'm not too fond of the idea of driving a Cobra around town that has a carburetor and an air cleaner sticking out of the hood.

Last edited by 520SC; 01-22-2018 at 11:52 AM..
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