Proven Horsepower Engine Combinations - 500hp Engine Combos

You asked for it. Our reader surveys say you want 500hp engine combos, and while there are several ways to get to that number, the majority of you want to see it without nitrous or a blower. It's seems that 500 hp is the new the 400 hp because everybody claims to have it and it seems easy to get. But is it? What has changed in the last 10 years that allowed an easy 500 to happen? The answer lies in huge jumps in cylinder-head design, low-dollar stroker cranks from overseas, and roller-cam technology that gives you lift and duration without the overlap and valvetrain wear. In this story, we've assembled eight engine combos that are easy to build with available parts, run on pump gas, and are the most economical use of factory blocks we could find. Drop one into your musclecar and feel what 500 hp is all about.

This 461ci Olds sits between... 

   

  read full caption

This 461ci Olds sits between the wheelwells of Tim Meirick's '70 442 running a slightly different combination of Edelbrock heads, 240/246 0.541/0.544-lift cam, and an Offenhauser Port-O-Sonic intake with an Edelbrock 750 carburetor. It runs 12.50s at 109.

Oldsmobile 468ci
Making 500 hp with a big-cubic-inch engine is relatively easy because of the engine's size. In terms of power, this isn't even 1.1 hp per cubic inch. There is really only one limitation to cranking this much power from a big-block Olds: cylinder-head flow. According to Olds guru Dick Miller of Dick Miller Racing (DMR), it's possible to make five big ones with stock iron heads-he prefers the early A, B, or C casting heads, but ultimately it will cost more to have DMR port your iron heads than to just buy a set of Edelbrock Olds Performer RPM aluminum castings that are ready to bolt on. Keep in mind that these heads require roller rockers that also add up on the bottom line.

As for a camshaft, Miller recommends a DMR-spec flat-tappet hydraulic with 244/246 degrees of duration at 0.050-inch tappet lift with 0.534/0.544-inch valve lift at a 1.6:1 rocker ratio with a lobe separation angle of 113 degrees installed with the intake centerline at 110 degrees ATDC. The earlier 455 engines enjoyed a stock 10.25:1 compression, while later engines dropped to roughly 8.5:1. More compression for the later engines can be gained with Speed-Pro forged pistons that will also add durability.

Miller suggests the Edelbrock Torker as the intake of choice, since it's worth a solid 20 hp over the dual-plane Performer. A 1-inch spacer will add another 10 hp, but unless you've got a cowl hood, the taller combination won't fit. A typical Holley or Speed Demon 750-cfm carburetor will offer excellent power and road manners, and 36 degrees of timing from a reliable distributor will make the most power. Miller also likes the Kooks 1 3/4-inch long-tube headers, but they cost more than the Hookers. The bare minimum exhaust is a mandrel-bent 2 1/2-inch system. While a 3-inch will probably make the best peak power, it will also be heavier and louder than the smaller pipes. Power should be right at 500 hp at around 5,400 rpm with peak torque of around 570 to 580 lb-ft at 4,000 rpm. This is not a high-winding package, which means shifting a big Olds at 5,700 to 5,800 rpm will deliver excellent results of high 11s at 115 mph in a 3,800-pound Cutlass with a gear ratio taller than 3.73. With gobs o' torque, you don't need much gear.

Dick Miller Racing
Hernando, MS
662/233-2301
dickmillerracing.com

The key to excellent Gen III... 

   

  read full caption

The key to excellent Gen III engine performance is the cylinder heads. A combination of a relatively small port cross-section with high flow numbers makes for a killer power combination of excellent torque and horsepower.

Chevy LS1 5.7L
The Gen III small-block is the engine of the future for hard-core car crafters looking for maximum power. This is also the smallest engine in our power combo at only 346 ci, yet it can achieve the power without resorting to an outrageous cylinder head/camshaft/high-rpm combination. To get the full skinny on a 500hp Gen III motor, we hustled out to Ken Duttweiler's shop in Saticoy, California.

Duttweiler's experience is mostly based around fuel-injected combinations using the factory computer, but a carbureted version would make similar if not slightly more power. According to Duttweiler, all it takes to make 500 hp is cylinder heads that flow 310 cfm or better along with a little more camshaft than stock. For a first-generation small-block Chevy, that's a tall order in the cfm department. But for the Gen III, there are easily a half-dozen heads out there that would fill these airflow shoes. If we had to pick one, Duttweiler agrees the GM Performance Parts CNC-ported LS6 heads are a good choice. The heads come completely ported and fitted with very light, hollow-stem 2.00-inch intake valves and 1.55-inch sodium-filled exhaust valves. GMPP claims these heads can only accommodate up to 0.570-inch valve lift, so you may need some better valvesprings along with a few other pieces. But the airflow is solid at 290 cfm-plus at 0.500-inch lift.

For a camshaft, Duttweiler says the hydraulic roller profile needs to be in the range of 224/236 degrees at 0.050-inch tappet lift with 0.580-inch lift and a lobe separation angle of 115 degrees advanced slightly with an intake centerline of 112 degrees. This is the smallest cam spec that would make this kind of power, as long as you combine the cam with good valvesprings and stiffer aftermarket 0.080-wall pushrods to prevent deflection. The pushrods are necessary because the stockers are weak. A close off-the-shelf cam we found was a Crane HR228 Zcam, but Crane can also custom-grind a cam if you choose to go that route, and the price is not as bad as you might think.

Best peak power will also be achieved with a FAST LSX intake manifold combined with a 90mm throttle body. Compression would also help this program. Duttweiler says cutting the heads 0.020 inch might bump the squeeze to 11:1, and of course a good set of headers like Kooks long-tube 1 3/4- or 1 7/8-inch primary-size pipes will help make torque as well as horsepower. We've seen large-tube headers work on even mild LS1 motors. The only other caveat Duttweiler mentioned is to not spin a stock LS1 over 6,800 rpm because the stock rod bolts are a bit questionable above that rpm. That rpm is also very hard on the heavy hydraulic roller valvetrain.

Crane Cams
Daytona Beach, FL
386/258-6174
cranecams.com

Kooks Custom Headers
Bayshore, NY
866/586-5665
kookscustomheaders.com

Scoggin-Dickey Parts Center
Lubbock, TX
800/456-0211
sdpc2000.com