Chevy Stroker 496 Big Block - Saturday Night Special
585 Lb-Ft & 672 Hp For The Strip
From the January, 2008 issue of Chevy High Performance
By Henry D, Sean Haggai
Photography by Henry D, Sean Haggai
For some, racing is no fun when you're constantly wrenching on the motor. Think about it; the whole point of hitting the track is to have fun, hammer the throttle, and slam some gears. The stresses of life dissolve, and you leave your week at the office there-at the office. But when your weekend of racing turns into completely dismantling your mill between runs just to make the next pass, you begin to realize that your night of fun has morphed into an evening of stress and anxiety. With this in mind, we set out to build a powerplant that'll bring back the fun with a serious seat-of-the-pants rush.
A quick call over to Coast High Performance in Torrance, California, landed us a bored and poked 454, netting us a total of 496 cubes. We knew we were going to need the bigger cubes, but we also knew the added inches wouldn't be a surefire guarantee of power. We wanted a slight bump in compression, and matching that to the right induction setup and camshaft would prove to go a long way. To bump up the bang within the cylinders, we went with a set of Probe dome pistons and bolted on a set of CNC-ported Edelbrock Victor Jr. cylinder heads with a Victor Jr. manifold as well.
For the baseline pulls, we used 104-octane fuel, made small adjustments along the way, such as tweaking the Holley carburetor, throwing additional timing at it, and checking the valve lash to make sure they were at 20/22 hot. After break-in, we dumped the Lucas break-in oil, trashed the filter, checked the oil for any metal debris, and added fresh 5W-30 oil with a new filter.
How'd it do? On 104-octane, the 496 pumped out 671 hp at 6,600 rpm and 586 lb-ft at 5,200. Impressive, yes! However, we were curious to see the results on pump gas. Willing to find out, we fired it up for another run at it and churned out an incredibly similar 672 hp at 6,600 and 585 lb-ft at 5,200. You have the numbers, but you have to read on to find out how to build one for yourself.
What We BuiltAn 11:1 stroker 496ci big-block
Check your valve lash, top off the fuel, and enjoy the smell of burning rubber!
496CI: A Closer Look 1. An...
496CI: A Closer Look
1. An Edelbrock Victor Jr. intake manifold matched our rectangular-port heads and had an optimum power range between 3,500 and 7,500 rpm.2. The Edelbrock Victor Jr. CNC heads offer 112cc combustion chambers and 2.25/1.90-inch intake/exhaust valves.
3. The Coast High Performance 496 big-block came with domed pistons for just $3,700.4. 2 1/8-inch headers were used and we added 18-inch collectors, showing no power loss.
5. A Milodon oil pan with pick-up and pump fed our motor and kept the oil pressure flowing at a solid 66 psi.
A cam from Comp featured 267/276...
A cam from Comp featured 267/276 degrees of duration and 0.435/ 0.470-inch intake/exhaust lift with a 110-degree lobe separation. It's an off-the-shelf grind and gave us the right amount of bump to get the air in and exhaust out. When installing the cam, prelube the lobes of the cam to help slide it in easier and be careful not to gouge or knick the cam bearings. Take your time.
To increase compression, we...
To increase compression, we used a set of Probe's domed slugs with a complete set of Performance Circle rings. We then hung the pistons on Probe's 6.385-inch 4340 H-beam rods and checked bearing clearances for proper slippage on the crank rod journals.
A 4150 Holley HP Series 1,000-cfm...
A 4150 Holley HP Series 1,000-cfm carburetor was practically ready right out of the box, requiring only minor tweaking of the idle and air mixture screws.
With the bottom end complete,...
With the bottom end complete, we installed the cam button and set the timing cover in place. It's a good idea to run a bead of sealant before and after you lay the gasket on. This way, the gasket is sandwiched between the two layers of sealant. No need to torque these bolts; tighten them until they are snug.
Even with a new oil pump,...
Even with a new oil pump, there are no guarantees it'll be completely debris-free. Unbolt the oil pumphousing plate cover and give it a good solvent rinse. Pour a bit of oil over the gears before you bolt the plate back on. Slide the oil pump drive through the main cap and bolt on the oil pump and pick-up.
For good measure, we rolled...
For good measure, we rolled the motor over (crank facing up). We mocked up the pan by laying it over on the pan rails, then we spun the crankshaft over a few revolutions after making sure the bolts lined up and our rods weren't going to rub into the bottom of the pan. Nothing knocked against the pan, so we again sandwiched a gasket with sealant and bolted it down.
For the head studs, we spread...
For the head studs, we spread thread sealant on the inner threads of the block and on the threads of the studs. We then laid the Fel-Pro gaskets on both sides and slid the Edelbrock heads onto the block. From there, we liberally spread moly-lube on the upper ends of the studs and spun the nuts with washers on. We torqued them from the center out in a clockwise fashion, first at 65 ft-lb, then 75 ft-lb.
We used a Comp Cams line of...
We used a Comp Cams line of T-bar lifters to match our solid roller.
Tickling the valves, we used...
Tickling the valves, we used 3/8-inch-diameter Comp pushrods with an 8.350-inch length on the intake and 9.400-inch length on the exhaust with a set of 1.7:1 Pro Magnum rockers up top and lashed them to 0.018/0.020 cold.
Before installing the manifold,...
Before installing the manifold, we applied a bead of sealant to the lifter valley wall and placed the gaskets over the intake ports. We laid the manifold on top and bolted it down.
Since we were looking for...
Since we were looking for upper-rpm flogs, we went with a single-plane Edelbrock Victor Jr. manifold. Something to keep in mind is that even with the occasional show cruises, this stump-puller is already producing 543 lb-ft at 4,100 rpm, so there's little concern for torque loss on the bottom end.
Edelbrock's Super Series valve...
Edelbrock's Super Series valve covers with PermaStar have a shine that won't fade or discolor, are easy to clean, and cost just $163.
An 8-inch professional-products...
An 8-inch professional-products damper was used because it's dimensionally the same as an OE 454 damper and extremely affordable at only $70-we couldn't beat it. Plus, the timing numbers are easy to read with engraved marks every 90 degrees.
|PEAK TORQUE ||581 |
|AVG. TORQUE ||555 |
|PEAK HP ||651 |
|AVG. HP ||574 |
|FINAL PULL |
|PEAK TORQUE ||585 |
|AVG. TORQUE ||562 |
|PEAK HP ||672 |
|AVG. HP ||581 |
|496 BUILD SPECS |
|Bore x stroke ||4.310x4.250 |
|Displacement ||496 ci |
|Head gasket thickness ||0.041 |
|Piston deck height ||0.005 |
|Total clearance ||0.046 |
|Compression ratio ||11:1 |
|Piston-to-wall clearance ||0.004 |
|Ring endgaps ||0.022, 0.024 |
|Rod bearing clearance ||0.0027 |
|Main bearing clearance ||0.0027 |
|Crank endplay ||0.007 |
|Main bearing cap torque ||105 ft-lb (w/moly-lube) |
|Rod bolt torque ||63 ft-lb (w/moly-lube) |
|Head bolt torque ||65/75 ft-lb (w/moly-lube) |
|* Except as noted, all dimensions are in inches. |
|PRICE SHEET ||Manufacturer ||Item ||PN ||Price |
|Coast High Performance ||High-compression short-block || ||$3,700 |
|Includes Gen IV 454 block bored 0.030, Probe 4340 H-beam rods and high-compression pistons, Perfect Circle piston rings, RPM overstroked crank |
|Comp Cams ||Retainers ||733-16 ||345 |
| ||Valvesprings ||26099-16 ||487 |
| ||Locks ||612-16 ||27 |
| ||Spring seats ||4774-16 ||43 |
| ||Lash caps ||621-16 ||43 |
| ||Intake pushrods ||7743-1 ||13 |
| ||Exhaust pushrods ||7755-1 ||13 |
| ||Lifters ||819-16 ||325 |
| ||1.7 rockers ||819-16 ||295 |
|Edelbrock ||Cylinder heads (bare) ||60419 ||1250 |
| ||Intake manifold ||2902 ||230 |
| ||Valve covers ||4180 ||163 |
|Fel-Pro ||Cylinder head gasket ||1017-1 ||45 |
| ||Intake gasket ||1211 ||17 |
|Milodon ||Oil pan ||30950 ||211 |
| ||Oil pump ||18760 ||75 |
| ||Oil pick-up ||18201 ||64 |
| ||Oil pump shaft ||23060 ||16 |
| ||Oil pan studs ||81305 ||23 |
| ||Oil pump baffle ||32505 ||8 |
| ||Dipstick ||22010 ||55 |
| ||BBC gasket pan set ||40200 ||22 |
| ||Head studs ||80133 ||200 |
| ||BBC timing chain ||15055 ||112 |
| ||Cam plate ||10777 ||14 |
| ||Cam button ||10776 ||13 |
| ||Timing cover ||14855 ||130 |
| ||Billet block-off ||65705 ||22 |
|Professional Products ||Balancer ||80005 ||70 |
| || ||TOTAL ||$8,031 |