Ok - so I'm building a blower motor trying to save a little money. Here's what sounds like a bonehead question. I've got a good condition 350 Chevy truck short block with .030 over cast 8.5 dished pistons. Does anybody have any experience good or bad running a 6-71 GMC blower with low boost - on this type of short block? This would be a street motor only. Here we go! Comments?
I built and ran one in my '31 coupe for a decade. Excellent street motor. Couldn't afford a blower, but the GM windage tray, the 340 HP-327" hydraulic cam, 1.92 or 2.02 intake heads, 750 Holley and Mallory dual point worked out fine. Torque and reliability, a great package. I'd ask Squirrel, or the SBC builders about their piston recommendations, Jahns and few others made forged stuff which might be better.
I'm sure you know common wisdom is that cast pistons don't work well with boost. I'm going to give you some of my own experience with an O/T project. We took "rebuilder special" 350 that was in good condition, but had all the cheapest parts in it, and bolted a turbo off a Dodge Cummins pickup on it. We got 447hp and the same torque on the engine dyno with port injection. Nothing broke. We then added the stock Dodge truck intercooler and more fuel, and ended up with 527hp and 605lb ft...and it still didn't break anything. Feed it plenty of fuel, and not much timing, and hope for the best... "Your mileage may vary..."
Thanks for the comments! I know forged pistons are the best way to go, however I've heard of several guys running blowers using the cast piston/truck motor. I'm going to give it a try and find out for myself how it goes. Thanks again/CWK
If you are just after looks and noise underdrive the blower a bunch, watch your timing and it should live.
Set it up right and tune it well and it'll be a good engine that lives a reasonably long life. Just don't let it rattle too much, don't get greedy with boost and keep it tuned up.
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