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 the wheelwells of Tim Meirick's '70 442 running a slightly di
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
|Speed-Pro forged pistons, 10.25:1||L2323F-30||Summit Racing||$319.60|
|Edelbrock RPM 455 heads||60519||Summit Racing||1,579.00|
|Edelbrock head-bolt kit||8558||Summit Racing||95.88|
|Edelbrock Torker 455||2730||Summit Racing||267.88|
|Fel-Pro head gasket||1155||Summit Racing||63.95|
|Harland Sharp 1.6 rockers||S5011||DMR||299.00|
|Hardened 3/8" pushrods||5678-GP||DMR||179.00|
|SCE intake gasket||179102||DMR||12.77|
|Hyd flat-tappet camshaft||custom||DMR||Call|
The key to excellent Gen III engine performance is the cylinder heads. A combination of a
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.
Daytona Beach, FL
Kooks Custom Headers
Scoggin-Dickey Parts Center
|GMPP CNC LS6 head, pr.||88958665||SDPC||$1,996.50|
|FAST LSX intake, 90mm||30-54003||Summit Racing||869.95|
|FAST 90mm throttle body||30-54019||Summit Racing||519.95|
|Comp conical springs||26918-16||Summit Racing||179.95|
|Comp pushrods, 5/16"||7955-16||Summit Racing||133.69|
|Crane Zcam hyd. roller||1449601||Summit Racing||399.98|
|Kooks 1 3/4 headers||6500RHS||Kooks Headers||864.90|
On JGM's dyno, this 466 easily blew past 500 hp, but it also made a spine-bending 565 lb-f
It doesn't get much easier to make 500 hp when you start with a giant motor. The Ford 460 is an easy jump, and most of the parts are a one-stop-shopping expedition if you're dialed into the Edelbrock connection. Jim Grubbs Motorsports built a 0.030-over 460 Ford that we detailed and tested in the Feb. '06 issue ("Easy 500 HP From the Ford 460.") After later flogging a bigger cam, we discovered that Edelbrock really did its homework on this gem. The Performer RPM package does exactly as advertised, making 514 hp at a loafing 5,400 and 565 lb-ft of torque at 4,400 rpm.
Start with a good, sealed-up short-block with at least 9.5:1 compression (we used Speed-Pro forgings). The Edelbrock Performer RPM flat-tappet hydraulic cam measures 234/244 degrees at 0.050-inch tappet lift with 0.556/0.581-inch lift with 1.7:1 rocker arms and a lobe separation angle of 108 degrees. We used a set of Harland Sharp aluminum roller rockers to tickle the valves. Head selection is also easy with a set of Edelbrock Performer RPM heads that offer 2.19/1.76-inch valves and good flow right out of the box. Grubbs just put a set of these heads on a much more aggressive 642ci stroker Ford 460 and made over 650 hp.
Clearly, the Edelbrock Performer RPM dual-plane intake was a no-brainer for this combo, along with a 750-cfm carburetor that was worth plenty of airflow to make the 500hp number. The trick is to make sure you can fit 1 3/4-inch headers on this beast along with a good 2 1/2-inch exhaust system that minimizes restrictions on the hot gas side. Larger headers only hurt the average power with no plus on the horsepower end. Set the timing at 36 degrees and let 'er rip!
Jim Grubbs Motorsports
Holley Performance Products
Bowling Green, KY
|Edelbrock Air Gap intake||7566||Summit Racing||$329.88|
|Edelbrock RPM 460 intake||7166||Summit Racing||205.95|
|Edelbrock RPM CJ heads||61649||Summit Racing||959.50 ea.|
|Edelbrock Performer cam kit||2167||Summit Racing||137.88|
|Harland Sharp 1.73 rockers||S4005||Summit Racing ||215.88|
|ARP head bolts||155-3603||Summit Racing||105.95|
|Holley 750-cfm carb mech.||0-4779C||Summit Racing||396.88|
Adding cubic inches is the easiest way to make more normally aspirated power. A larger eng
Small-Block Chevy 383ci
While the first-generation small-block Chevy enjoys the fruits of more horsepower tuning than probably any other engine on the planet, it also suffers from the limitations of its design. Since cylinder-head flow is limited compared with the Gen III engine, we chose to build a 383 with a few more inches to make up for its airflow limitations.
Expect to step up to a good aluminum head like the fully CNC-ported AFR 195 to flow enough air to make excellent torque and still clear the 500hp cutoff. We know AFR has an all-new set of port designs that might be out by the time you read this, and the new AFR 195 is a gangbuster. We've seen the flow numbers on the prototypes and they are killer. If you're willing to be patient for a few months to get heads that can flow 280-plus cfm, that should be worth the wait.
But even if you use the fully ported current version AFR 195 at around 260 cfm, this head will still step up past the 500hp limit. For a camshaft, we're going with a Comp mechanical roller XR274 grind that will spec out at 236/242 at 0.050-inch tappet lift with 0.564/0.570-inch lift with a 110-degree lobe separation angle. This cam will require some stout valvesprings, a good set of roller rockers like Comp's Hi-Tech series, and good pushrods. Combine this cam with 10.5:1 compression, a Victor Jr. single-plane intake manifold, a Holley 0-4779 750-cfm double-pumper carb, and a set of 1 3/4-inch headers, and you have a package that should be worthy of 515 hp at 6,000 rpm and will still make excellent torque with 510 lb-ft at 4,400 rpm. Then your biggest problem will be figuring out how to make the tires stick.
Air Flow Research
|AFR 195cc heads||1038||AFR||$1,324.00|
|Comp XR274 roller cam|| 12-770-8||Summit Racing|| 245.95|
|Rockers, 1.6 Hi-Tech||1105-16||Summit Racing|| 407.69|
|Edelbrock Victor Jr. intake||2975||Summit Racing|| 185.88|
|Holley 750 mech. sec. carb||0-4779C||Summit Racing|| 399.95|
Since the mid-'60s and the introduction of the RB engine (raised block), Mopar guys have had it pretty good. The venerable 440 has always been a relatively cheap, reliable source of horsepower and torque. Enthusiasts devoted to other brands have to pay extra for things that are stock on the Chrysler big-block, such as an external oil pump and shaft rockers. The skirted block, although heavy, provides a very stable bottom-end platform, and the cavernous crankcase lends itself to the addition of various stroker cranks without much fuss. However, since stroker engines can be expensive, do you really need the extra inches to make 500 street-friendly horsepower and 525 lb-ft of torque? That's the question we put to Mike Johnson at JMS Racing Engines in Monrovia, California. Johnson says, "No problem, with modern cam profiles and cylinder heads, 500 hp and 525 lb-ft should be relatively easy, and it shouldn't cost too much, either."
Johnson suggests the use of Edelbrock Performer RPM cylinder heads. Used in conjunction with stock replacement KB Silvolite hypereutectic pistons, the closed-chamber design of the 84cc heads provides a great quench area to deter detonation and puts the compression ratio at 10.3:1 when the pistons are at zero deck height. The heads can be used right out of the box with a Performer RPM manifold.
Johnson tells us the LY connecting-rod forgings are plentiful, inexpensive, and reliably capable of handling much more than 500 hp when equipped with quality hardware. Pre-'73 440s all have forged cranks that also will handle the load, so we used these essentially stock components.
Lunati ground the cam using some lobes designed specifically for the Chrysler lifter. As most Chrysler guys know, the large 0.904-inch lifters allow for faster ramp rates and higher lift without the penalty of long duration times, and Johnson planned to take advantage of this. He wanted the torque curve to be flat, with peak horsepower coming in below 5,800 rpm, so he chose a solid flat-tappet cam with 239/243 degrees of duration at 0.050 and 0.536/0.547-inch lift. The exhaust flow of the Edelbrock head is good enough that a larger split between intake and exhaust duration isn't necessary at this power level. The cam was ground with a 110-degree lobe separation and an intake centerline of 106 degrees.
A 454 core is going for almost $1,000 in California. Soon it will be cheaper to build 540s
On a dyno, this combo made 527 hp and 557 lb-ft. The peak horsepower was achieved at 5,600 rpm, and the peak torque occurred at 4,100 rpm, making over 500 lb-ft from 2,900 rpm all the way to 5,500 rpm. In fact, the average torque throughout the entire pull was 529 lb-ft. Even with all that power, it still pulled 12 in-Hg at an idle, just perfect for the street.
JMS Racing Engines
|Edelbrock RPM Chrysler heads||60929||Summit Racing||$1,359.00|
|Edelbrock RPM manifold||7193||Summit Racing||199.88|
|KB Silvolite pistons||KB237||Summit Racing||313.99|
|ARP rod bolts||135-6402||Summit Racing||51.88|
|Crane 1.5 rocker arms||64790-1||Summit Racing||349.95|
|Holley HP 950||80496-1||Summit Racing||679.95|
Big-Block Chevy 496ci
See if you follow this logic. If you are going to make 500 hp with a production iron-block 454, you have to change the pistons, and that means you are going to have to tear the engine down. If there is any machining needed on the rods, including shot-peening, bushing, or repair, it costs almost the same to buy a good set of I-beam connecting rods with ARP bolts. In other words, you should. While you are there, a cast 4.250-stroke crank, instead of the stock 4.000-inch, is available for $259, and since the Rat is externally balanced, you are going to have to pay to balance the rebuilt engine anyway. The block notching should run about $125 in labor.
That gives you a 496 instead of a 454, and the guys at Coast Performance say combine that with a good set of aluminum heads, and it isn't 500 easy horsepower anymore, it's more like 600. Low cost is the beauty of building a Chevy. At $1,700 completely assembled, the Edelbrock heads are getting to the point where they are cheaper than rebuilding iron ones. But, if you knew what you were doing, you could rebuild a set of oval-port heads and do a little pocket porting to get the iron to flow like the aluminum. Assuming a core charge of $200 for factory iron, the price for parts and labor is around $1,200 total. So in this case, we would use the Edelbrock Performer RPM 454-0 heads. They are oval-port heads that take on some of the characteristics of a big rectangular port head without the loss of low-end torque.
Speaking with Chris Huff at Coast, we found that customers want the biggest engine they can afford, so Coast tries to find the late one-piece main-seal-style blocks and bores them 0.060-over. With the Edelbrock heads' 110cc chambers, a low-dome forged piston will give you around 9.5:1 so you can run it on pump gas.
At this horsepower level, you don't really need to give up low-end torque and driveability and run a single-plane intake. So Coast also recommends the Edelbrock RPM Air Gap 2-0. It offers a broad torque curve without giving up too much high-rpm horsepower.
Using a roller cam is an expensive proposition on a big-block, so the recommendation is an Elgin flat-tappet hydraulic with 234/244 duration at 0.050 with 0.553/0.578 lift ground on a 112-degree lobe separation angle. Coast always uses Probe Industries 1.7 roller rockers to enhance the valveguide life and tops the combo off with a Speed Demon 750-cfm carburetor.
Coast High Performance
|Cast 4.250-stroke crank||13766||Coast High Performance|| $259.00|
|Elgin flat-tappet cam ||14318||Coast High Performance||92.00|
|1.7 rocker arms||11645||Coast High Performance||289.00|
|Edelbrock RPM heads||60459||Summit Racing||1,739.00 pr.|
|6.135-inch I-beam rods||11663 ||Coast High Performance||299.00|
|Edelbrock Air Gap manifold||7561||Summit Racing||235.88|
|Speed Demon 750 carb ||132-1402010DR ||Jegs||711.99|
Small-Block Ford 408ci
We've seen naturally aspirated 500hp 302s, and they're rowdy and right on the verge of disaster. On the other hand, the 351 Windsor-based engine that came in fullsize cars and trucks from 1969 all the way to about 2003 has the displacement for good torque and with the right combination of parts can make an easy streetable 520 hp.
Wow, that looks pricey.
The guys at Coast High Performance build Windsor-based 408s with 4.00-inch strokes and 4.030 bores using tall-deck 351s and 6.2-inch rods. The preferred block is from the Ford Lightning truck that has a factory roller cam already installed, but short of that, the '82-and-later block has the one-piece rear main seal, and you can buy a roller-cam retrofit kit with a small base circle so the lifters will clear the dog bones. Then you just drill and tap for the lifter galley spider. All the blocks require clearancing for the rod bolts when using the stroker crank, and Coast suggests using a main girdle for combinations approaching 500 hp and engine speeds nearing 7,000 rpm. For only $169, the girdle is cheap insurance. Another trick is finding a '69-'70 block that has thicker cylinder walls and will take a 0.060 bore for a rebuild later. You can also step up to a Ford Motorsports block for another $1,000 to get the thick walls, one-piece rear main seal, and roller cam in one package.
The cam choice is the Crane 248/256 at 0.050 duration hydraulic roller with 0.595/0.605 lift ground on a 110 lobe center. It may sound a little radical, but at 408 inches, Coast reports it is actually very docile and driveable. Coast uses the AFR 205 street/strip heads that flow 306 cfm right around 0.600 lift. It can be used out of the box after you set the seat pressure to match the cam. For carbureted applications, Coast uses the Edelbrock Victor Jr. single-plane intake, Holley HP 750, and an engine compression ratio of 9.5:1. The fuel-injected applications get 10.0:1-10.5:1 because they usually have better fuel and timing control.
The 408 will fit in your Fox-body or Cobra kit car with a cowl hood, and there are off-the-shelf headers for '64-'66 Mustangs. The Fox engine mounts are the same for the 351 and the 302, you'll just have to use a Fox oil pan.
Using 1 3/4 long-tube headers, this combination should make 520 at 6,300 rpm, which is the limit of the lifters, and 490 lb-ft at 4,200 rpm. The typical Fox-body will be around 3,200 pounds with a five-speed, and a 3.73 gear will give you mid-11s at 120 mph.
Coast High Performance
|AFR 205 cylinder heads||1450||Coast High Performance||$1,699.00|
|Crane hydraulic roller cam||13892||Coast High Performance||299.00|
|Roller retrofit kit||11956||Coast High Performance||69.00|
|4340 4.00-inch forged crank ||10009||Coast High Performance||599.00|
|Edelbrock Victor Jr. intake||2981||Summit Racing||257.95|
|Probe 1.6 rocker arms|| 11273 ||Coast High Performance||269.00 set|
|Reverse-dome pistons (9.5:1)||12360-30 ||Coast High Performance||535.00 set|
|Holley HP 750 carb||0-80528-1||Summit Racing||637.95|
At 4.210 inches, the Pontiac 455 has one of the largest factory strokes available. The bad news is that you just don't see them laying around like you used to. Instead, Bruce Fulper at PontiacEngines.com (aka Rock 'n' Roll Engineering) showed us that the easiest way to build a 455 is to buy any '67-'75 400 block and use a 455 crank. Fulper has experimented and says the two-bolt block will live up to 900 hp with proper care and a main stud kit. The '76-'79 blocks have thinner main webs and should be avoided for anything other than a mild street build.
If you do not have a stock 455 crank and block, a 4.210-inch-stroke aftermarket crank is available in two main diameters. Stock, which is 3.250 inches and will fit a 421, 428, or 455 block, or a 3.00-inch-diameter that will fit into a 326, 350, 389, or 400 block. These cranks inspected and balanced are only about $500. When using a 3.00-inch-main 455 crank, you will need to grind 0.100 off the block in the area where the front counterweight touches.
Fulper warns against using an aftermarket crank assembly that uses a 4.250 stroke but comes with a heavier 6.800 rod length for this combination. The Pontiac's stock rod length is 6.625 and in his opinion it's already too long. Moving from a 4.210 to a 4.250 only adds 0.040 to the stroke, which isn't enough to measure on a dyno. Retaining the stock-length rods and stroke makes replacing parts easier with the added benefit of a lighter rotating assembly for less money. Fulper recommends forged I-beam rods with ARP bolts.
We ran across two Pontiac 400s in the wrecking yard. Even the early ones are still out the
The large bore and stroke can make a lot of torque, even with stock cast-iron heads, but even using ported cast-iron heads, it takes a large roller cam to make 500 hp. So the horsepower is limited by the head selection. The secret to Fulper's low-rpm power is in his ported Edelbrock castings. He buys them bare, ports them, and assembles them with some finish work on the valve angles and matching valve springs. The heads are priced at about $800 more than the complete unported version, but because the aftermarket crank is inexpensive and you don't need an aftermarket block, you can spend the money on head work instead.
Fulper also says the large dual-plane Edelbrock RPM intake manifold can feed an 800-horse 455 with a 150-shot of nitrous. You can use it unported, as the runner volumes are already large enough for the job.
For the cam, Fulper recommends the least expensive route using a custom solid flat-tappet grind with hydraulic lifters. Only certain grinds can do this, so don't try ordering a different profile without consulting Fulper or Dean Harvey at Comp Cams, who also worked on this combo. A recent 455 build using this cam made 500 hp at 4,800 rpm and more importantly 558 lb-ft at 3,000 rpm. With the right street converter, this combo will push any 3,500-pound car into the mid-11s and do it with a 3:55 gear. Here are the specs: Intake opens 10 degrees BTDC and closes at 46 degrees ABDC. Exhaust opens 56 degrees BBDC and closes 4 degrees ATDC. The duration is 236/240 at 0.050 on a 112 lobe separation angle installed on a 108. Fulper uses Harland Sharp 1.5 rockers for $225 a set or the more budget-minded Comp Cams 1.52 ratio roller-tip rockers.
Grand Terrace, CA
|Cast steel 4.210 stroke crank||RRE4210C||RRE||$500.00|
|I-beam forged rods||CR455||RRE||350.00|
|Edelbrock RPM intake||7156||RRE||185.00|
|Edelbrock ported RPM heads||60569||RRE||2,500.00|
|ARP two-bolt main stud kit||194-5401||RRE||95.00|
|Harland Sharp 1.5 full roller rockers||6001||RRE||230.00|
|Comp Cams roller tip 1.52||1451-16||RRE||150.00|
|Speed Demon 750||1402010||RRE||439.99|
|Speed Demon 850||1563010||RRE||439.99|
|CP pistons, custom||RREcp455||RRE||595.00|
|Cam ground by Comp Cams||51-000-S||RRE||265.00|