509 Aluminum Big Block Engine Build - Comp Cams Camshaft

409 Aluminum Big Block Engine Build Prototype

Like a lot of other segments in our hobby, the legendary 409 is enjoying a new heyday. The beginning was about 10 to 15 years ago when stroker kits hit the scene, punching displacement up to 482 ci. Within the last four or five years, strides have been made with aluminum heads, dedicated distributors, reproduction and aftermarket oil pans, roller cams and roller rockers. Leading the charge since running a blown and injected 409-powered '33 Willys in the early '60s has been Lamar Walden.

From billet blocks to rocker arms, Walden has made just about everything possible for a 409. His most recent venture has been to team up with Bill Mitchell at World Products to develop an aluminum 409 block.

"The problem is that blocks have just about dried up," Walden says. "You can get race or street heads and intakes, billet timing chains, valve covers, crank kits, good pistons, and everything else. The only thing you can't get-and the most important-is the block."

There were originally two factory blocks: passenger car and truck. The truck blocks are the most common, but have a handicap in the form of a large, compression-killing notch cut in the side of the bore. Opinions vary on "The Notch." Over the years, it's been said the notch unshrouds the exhaust valve, which is true. However, the benefit of the unshrouded valve usually doesn't outweigh the compression drop. It's good for a forced induction application, and some race engines. Prices for buildable passenger car blocks range from $2,500-$4,000 (and cracked cylinder walls or water jackets aren't deal breakers), while truck blocks aren't far behind.

As much as we love the '09, we have to be honest and admit there are several shortcomings: The deck is a little on the thin side, making high/race compression ratios, forced induction or nitrous a dicey proposition (flex does bad things to head gaskets). They also have a tendency to pull head bolts out. The area where the exterior of the block meets the deck is also thin-Walden has dozens of blocks that were cracked from running too hot or freezing. (Fortunately, he's developed a method of repair).

And then there are the 409-specific bits that can add hundreds of dollars to a build: oil pan, timing cover, distributor (or spacer sleeve) and harmonic balancer. Reproduction oil pans are in the neighborhood of $300, while original timing chain covers are scarce. And you need the right one, because there are two timing tab locations.

The first aluminum 409 block out of World Products' foundry. Walden got the first two samples to make sure everything was in the right spot before World went into full production. This block needed a few revisions, like prototypes always do, but it was about 98-percent "there."
The first aluminum 409 block out of World Products' foundry. Walden got the first two samp
The World aluminum block comes ready to assemble. That's a big deal when figuring in the cost to refurbish an original iron lung. Walden made sure the World block was reinforced and beefed up in critical areas that were lacking on original 409 blocks.
The World aluminum block comes ready to assemble. That's a big deal when figuring in the c
Standard on the World block are beefy splayed 4-bolt main caps, a necessity when building a stroker big-block. Main journals are standard big-block Chevy spec.
Standard on the World block are beefy splayed 4-bolt main caps, a necessity when building

Not all the 509 blocks will be machined for O-rings, but Walden machined this one to reinforce the prototype copper head gaskets.
Not all the 509 blocks will be machined for O-rings, but Walden machined this one to reinf
Total Seal gapless secondary ring sets were used. The unique deck angle of the 409 requires a specific ring squaring tool to ensure ring gaps are precise.
Total Seal gapless secondary ring sets were used. The unique deck angle of the 409 require
Note the ridge: Below the ridge is the cylinder bore, above the ridge is the combustion chamber. That ridge is critical to 409s-without it, the rings pull carbon deposits down into the bore, wiping out the rings, bores and piston skirts. Most machine shops don't realize this, never mind being set up to put it back after boring the cylinder.
Note the ridge: Below the ridge is the cylinder bore, above the ridge is the combustion ch

Geneology of the 409 piston: far left is a stocker, the middle shows one of Walden's custom-made stroker 482 slugs (note the raised pin height and less overall mass), and on the right is the latest offering for the World 509 block: much taller pin-height, considerably less mass. The 509 comes with a 4.500-inch bore, while stock 409 is 4.3125-inch. Race pistons are even more radical.
Geneology of the 409 piston: far left is a stocker, the middle shows one of Walden's custo
This engine received a set of Walden's pistons, with a 10.5:1 CR, and 0.250-inch longer Eagle big-block Chevy rods.
This engine received a set of Walden's pistons, with a 10.5:1 CR, and 0.250-inch longer Ea
Cam choice is a solid roller, ground by Comp. The 409 cam is the same length as a BBC, but the valve layout is SBC, requiring 409-specific cams. Lamar has his own part number in the Comp catalog, but it's pretty much a blank-lobe profiles are cut for each application. Ask Lamar what the specs are, and he'll tell you, but after a while you'll realize he never really got around to saying, exactly.
Cam choice is a solid roller, ground by Comp. The 409 cam is the same length as a BBC, but

Walden and World Products addressed these issues with a new aluminum block, that actually measures 509 with the as-delivered 4.5-inch bore and a 4-inch stroke crank. There's a thicker deck, a dual-pattern oil pan rail to accept an original 409 pan or a readily-available big-block Chevy pan, and a BBC timing chain cover pattern to accept any factory or aftermarket piece, including billet covers and belt drives.

"We kept the things that make it a 409," Walden said. "Obviously, the heads and the deck are what make the engine, but nothing looks like a 409 pan so they can still use it, and we had to keep the 409 water pump, too. That's almost as visually important as the heads."

What has many excited is the price for the 509 block-at press time, the block was shown on World's website retailing for $5,549, which sounds like a chunk-until you do the math. Take a good-deal $2,500 iron block, then add all the machine work required to make it usable. Boring a 409 not only requires specific know-how, it requires several additional machining operations due to the combustion chamber being in the block. Many blocks require a sleeve or two by now, which is no big deal, but it's added expense. And then of course you still have 2-bolt main caps, unless you step up to 4-bolt caps and the expense to install them-required with a stroker crank. And the main stud kit. Toss in the OE oil pan and timing cover, and you'll easily have $4,000-$6,000 in a prepped block ready to go. You could have a better, stronger and lighter W-block (with more cubes) for the same money.

Lamar had the first two prototype World 409 blocks shipped to his Doraville, Georgia, shop, and we followed along while he put the first together for a customer. The build was simple: mild cam (with specs Lamar guards like he's still Pro Stock racing), mild 10.5:1 compression ratio, Lamar's "-690" aluminum street heads topped with a brand-new Hilborn injection intake converted to EFI. The bruiser thumped out 667 lb-ft of torque at 5,500 rpm, and was still climbing at 655 hp when they ended the pull at 6,500 rpm. "It's not a race motor," Lamar told us, "so there was no point in running it all the way up."

With a set of his Z11 race heads, more compression and cam, another engine they built for Nostalgia Super Stock racer Barry Camp went well past 750 hp and another 2,000 rpm. And that was through a pair of carbs. The Hilborn they tested on this engine had 2.5-inch throttle blades, but 3-inch discs are available. The blocks can also be punched out a lot more, so we're certain Walden hasn't come close to wringing all there is from the new aluminum W-motor.

Crank is an Eagle 4-inch stroker big-block unit, up from the stock 3.50-inch stroke. The rotating assembly has been balanced. Any time we follow along on an engine build with the Waldens, we like to make Rob hold the crank up in the air while taking our sweet time shooting pics. He likes that.
Crank is an Eagle 4-inch stroker big-block unit, up from the stock 3.50-inch stroke. The r
Note the valve reliefs in the pistons-they have to go into the block in the correct order and orientation.
Note the valve reliefs in the pistons-they have to go into the block in the correct order
Here's the big deal with 348/409 engines: the combustion chamber is in the block. The inboard side of the piston comes up flush (or very nearly) with the deck/bottom of the head. The wedge-shaped area on the outboard side is the combustion chamber. The bottom of the cylinder head is flat, as you'll see in a moment. That wedge is why the deck is not at 90 degrees to the bore.
Here's the big deal with 348/409 engines: the combustion chamber is in the block. The inbo

Even with custom-spec'd parts, every cam is degreed.
This is the first set of copper head gaskets Walden had sourced for the big-bore W-engine. Because of the deck's angle, the bore hole for the gasket is oblong, rather than perfectly round.
This is the first set of copper head gaskets Walden had sourced for the big-bore W-engine.
The aluminum block and head combo was secured with ARP head studs.

Walden has been making aluminum street heads based off the high-performance factory castings for a while, and still had the prototypes in his shop.
Walden has been making aluminum street heads based off the high-performance factory castin
Besides the odd shape of the valve covers, the bottom of the head shows the lack of combustion chambers, and the SBC valve layout. The heads were fitted with 2.25-inch intake and 1.72-inch exhaust valves, with the intakes flowing more than 350cfm at 0.700-inch lift.
Besides the odd shape of the valve covers, the bottom of the head shows the lack of combus
Stock 409 rocker arms were 1.75 ratio. For valvetrain stability on his high-performance, aluminum-headed engines, Walden designed these pedestal-mounted full-roller rockers. These retain the stock ratio.
Stock 409 rocker arms were 1.75 ratio. For valvetrain stability on his high-performance, a

The rocker pedestal boss on the head is machined for the dowel to locate the pedestal, which is secured by the rocker bolt.
The rocker pedestal boss on the head is machined for the dowel to locate the pedestal, whi
Note the funky angles of the rocker arms. Walden's -690 heads are based on the factory 425-horse street heads, but have had improvements made to the valve location and ports, influenced by the factory Z11 heads.
Note the funky angles of the rocker arms. Walden's -690 heads are based on the factory 425
Lamar designed lifter bodies with offset pushrod cups to gain extra clearance and improve pushrod angles.
Lamar designed lifter bodies with offset pushrod cups to gain extra clearance and improve

Walden's billet timing chain cover, with integral cam button, was installed. Big-block Chevy and 409 timing covers aren't interchangeable, but they are on the new aluminum block, opening up the possibilities for much easier-to-find BBC covers, and readily-available belt drives and crank-trigger ignition systems.
Walden's billet timing chain cover, with integral cam button, was installed. Big-block Che
Nothing looks like a 409 water pump, and keeping that unique piece was a prerequisite for the aluminum block, though a standard BBC piece would have been less work in the design phase. Walden has had his own aluminum pumps cast for years, with a reinforced bearing housing.
Nothing looks like a 409 water pump, and keeping that unique piece was a prerequisite for
After the aluminum 509 block was announced, Hilborn contacted Lamar and wanted to do a retro fuel injection unit. The Hilborn unit has bosses for mechanical or electronic fuel injection, and three sizes of butterflies. This is the first, and uses 2.5-inch butterflies, 60-pound injectors, and is controlled by a FAST computer system and distributor. The 3-piece intake (injector banks and a separate valley cover) was powder coated black.
After the aluminum 509 block was announced, Hilborn contacted Lamar and wanted to do a ret

Finishing the prototype engine is a new serpentine belt-drive system. Unlike other systems on the market, this can be tailored to mount any combination of power steering, A/C, or dual alternators, without a bunch of additional "dummy" idlers. Lamar reversed the water pump to work with these. Note the humped spokes in the pulleys, inspired by the valve cover's shape. This set-up was hours old when we shot it, and wasn't completely finished.
Finishing the prototype engine is a new serpentine belt-drive system. Unlike other systems

RPM - HP - TQ
3,300 - 251 - 533 / 3,400 - 262 - 545 / 3,500 - 273 - 552
3,600 - 273 - 532 / 3,700 - 281 - 531 / 3,800 - 293 - 532
3,900 - 304 - 534 / 4,000 - 314 - 539 / 4,100 - 330 - 550
4,200 - 342 - 556 / 4,300 - 366 - 571 / 4,400 - 384 - 578
4,500 - 411 - 591 / 4,600 - 439 - 609 / 4,700 - 450 - 618
4,800 - 487 - 629 / 4,900 - 486 - 639 / 5,000 - 496 - 643
5,100 - 506 - 648 / 5,200 - 527 - 655 / 5,300 - 543 - 659
5,400 - 555 - 662 / 5,500 - 573 - 667 / 5,600 - 584 - 665
5,700 - 589 - 660 / 5,800 - 603 - 660 / 5,900 - 619 - 660
6,000 - 627 - 656 / 6,100 - 636 - 653 / 6,200 - 642 - 649
6,300 - 643 - 634 / 6,400 - 648 - 630 / 6,500 - 655 - 628

SOURCES
World Products 51 Trade Zone Court Ronkonkoma NY 11779 631-981-1918 www.worldcastings.com	Lamar Walden Automotive 6 Steve Drive #B Doraville GA 30340 770-449-0315 www.lamarwaldenautomotive.com