Torque Tales - Car Craft Magazine

Torque Tales - Tech
Ccrp 0412 Z+small Block+front View Ccrp 0412 S+small Block+front View

Yeah, big 600-plus horsepower numbers are mighty impressive on magazine covers, and those monster lumpy cams will wow all the pretenders at the burger stand on Friday night. But those are wild, wish-book engines that few of us can afford. So let's talk about a street small-block that just about anybody can squeeze out of his wallet.

Powerhouse is a company out of Bakersfield, California, that has been offering stoker engine kits for over 19 years. The 383ci small-block Chevy is its most prolific offering and therefore also the most affordable. Amazingly, you can pick up a stroker small-block Chevy rotator kit from Powerhouse for as little as $580. That's the basic kit, but it does get you a crank, rods, pistons, rings, and bearings, plus a few more pieces. That sounded almost too good to be true, so we decided to build one for ourselves.

Parts And PiecesThe Powerhouse rotating assembly consists of a brand-new Scat crank, rebuilt production 5.7-inch connecting rods, and a set of dished hypereutectic pistons, rings, bearings, and a gasket set. For a few more bucks you can also add balancing, a new, externally balanced Pioneer dampner, and a Pioneer flexplate. Because this is a stroker package, CC's engine master Ed Taylor took a die-grinder to the block's pan rails to ensure the rods would clear. Powerhouse also trimmed the rod bolts to ensure that the rods would clear the camshaft. Finally, Jim Grubbs Motorsports, in Valencia, California, did an excellent job of torque-plate honing to fit the pistons and installing our cam bearings.

Since this is a street engine with a budget focus, we also opted for a set of stock iron Vortec heads. While these heads may sound boring, don't be fooled. Vortecs offer excellent flow for their small 1.94/1.50-inch valve size and, combined with an excellent 64cc combustion chamber, can make outstanding power. All we did was exchange the stock valvesprings for a set of Pioneer conical type springs and elongate the pushrod holes to accommodate the additional lift from the Pioneer 1.6:1 stamped rockers.

To top off our small-block exercise, we chose an Edelbrock Performer Vortec RPM Air Gap intake since we've yet to find a manifold that will beat it when it comes to making both torque and horsepower. See, we're greedy-we want it all. For a carburetor, we stepped up to a Quick Fuel Technologies 750 vacuum secondary carburetor with an electric choke that would ensure good power while still delivering the kind of throttle response and street manners that we've come to expect.

Taylor took his time assembling the Powerhouse 383, ensuring that we had no problems with either the rods and cam or between the rods and the block. Taylor also measured all bearing clearances, crank endplay, and rod side clearances during this trial assembly period to ensure that all the clearances were within spec. This paid off because he did have to make some minor adjustments to bearing clearances, and one pair of rods measured too tight for side clearance, but these are typical issues that were easily remedied.

Test DayOnce Taylor had the Powerhouse 383 fully assembled and pressure-lubed, it went up on the Digilog dyno at Kenny Duttweiler's shop along with a set of 151/48-inch Hooker headers muffled with a pair of 211/42-inch pipes leading to a set of Flowmaster street mufflers. After completing the break-in period for the cam and rechecking the valve lash to ensure nothing changed, we were ready to test.

After the engine was content on 91-octane pump gas with 34 degrees of total ignition timing, the real fun started. Taylor pulled the handle on the dyno and watched as our Powerhouse budget Mouse lived up to its name with 444 lb-ft of torque at 3,600 rpm and a peak power rating of 375 hp at a very conservative 5,400 rpm. As you can see from the Power Curve chart, the engine averaged 404 lb-ft of torque throughout the entire rpm band from 2,200 to 5,800 rpm while delivering a respectable 1,800-rpm power band between peak torque and peak horsepower.

Just to show you what this is worth in the car, we plugged this exact power curve into the Racing Systems Analysis Quarter Pro dragstrip simulation program using a 3,700-pound car with a 3.55 gear, 2,600-rpm stall speed converter, TH350 trans, 26x9-inch sticky M/T tires and shifting at 6,000 rpm. We simulated the car at sea level on a 77-degree day, which is very good air. Amazingly, even with this heavy car and only 3.55 gears, the simulation spit out a respectable 12.54@108.9-mph pass with a 1.87-second 60-foot time.

ConclusionEven with the new parts we used, you could duplicate a similar long-block with Powerhouse parts (including the Vortec heads) for well under $2,000. Crank in a bigger cam and the horsepower will climb, but it will also sacrifice torque. As it is, this is a great package with an idle vacuum of almost 13 inches at 750 rpm, making this engine very driveable in almost any kind of street application. There's never been a better time than right now to build a stout 375hp first-generation small-block Chevy engine.

Cam Specs Cam Advertised Duration Lift Lobe Duration @ 0.050 1.5:1 (1.6:1) Sep. Isky 270/280 Int. 270 221 0.465 (0.496) 112 Flat-tappet hyd. Exh. 280 232 0.485 (0.517)

Power Curve Powermaster 383 RPM TQ HP 2,200 379 159 2,400 387 177 2,600 399 198 2,800 408 217 3,000 415 237 3,200 427 260 3,400 440 285 3,600 444 304 3,800 443 320 4,000 440 335 4,200 438 350 4,400 430 360 4,600 420 368 4,800 409 373 5,000 394 375 5,200 377 374 5,400 365 375 5,600 340 362 5,800 323 357 Peak 444 375 Avg 404 304

Parts ListThe following part numbers are the major components we used to assemble this small-block. The Powerhouse component prices are from Powerhouse while the GM Performance Parts block and Vortec head costs are from Scoggin-Dickey Performance Center. The remaining component prices come from various other readily available sources.

Component Manufacturer PN Price Cylinder block, 350 GMPP 10066034 $580 Cylinder heads, Vortec GMPP 12558060 500 383 Engine kit Powerhouse 383-SK 489 w/balance, balancer & flexplate 199 Camshaft Isky 20127/281-12 109 Lifters, anti-pump up Powerhouse 817R 40 Rocker arms, 1.6, rail Pioneer 818020 (4) 81 Pushrods Pioneer 815205 (16) 96 Valvesprings, conical Pioneer 810109 (4) 34 Retainers Pioneer 817109 97 Freeze plugs, brass Pioneer PE100BR 11 Intake, Vortec RPM AG Edelbrock 7516 226 Carburetor, 750 cfm Quick Fuel 750 Pro Vac 350 Distributor Pertronix D100701 220 Plug wires, 8mm Pertronix 804280 31 Oil pump Melling M55 14 Oil pan & pickup Trans Dapt 0168 185 Timing chain cover Trans Dapt 9915 28 Water neck Trans Dapt 9929 12 Valve covers, coated Trans Dapt 9919 95 Water pump pulley, LWP Trans Dapt 9604 29 Crank pulley, LWP Trans Dapt 9607 50 Alternator bracket, upper Trans Dapt 9320 16 Alternator bracket, lower Trans Dapt 9637 7 Distributor, Flamethrower Pertronix D100701 220 Plug wires, 7mm Pertronix 708180 47 Block machining JGM - 135 Install cam bearings JGM - 44