Super Chevy Magazine Homepage Super Chevy
Facebook Click here to find out more!

509 Aluminum Big Block Engine Build - W=Wow!

Lamar Walden Put Together The First Of His All-Aluminum W-Motors And We Were There.

By Brad Ocock, Photography by Brad Ocock
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.

  • 409 Aluminum Big Block Engine Build Serial Number One
    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."
    409 Aluminum Big Block Engine Build Serial Number One
    The first aluminum 409 block out of World Products' foundry. Walden got the first two samp
  • 409 Aluminum Big Block Engine Build Ready To Assemble
    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.
    409 Aluminum Big Block Engine Build Ready To Assemble
    The World aluminum block comes ready to assemble. That's a big deal when figuring in the c
  • 409 Aluminum Big Block Engine Build Splayed 4 Bolt Main Caps
    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.
    409 Aluminum Big Block Engine Build Splayed 4 Bolt Main Caps
    Standard on the World block are beefy splayed 4-bolt main caps, a necessity when building
  • 409 Aluminum Big Block Engine Build Walden Machined O Rings
    Not all the 509 blocks will be machined for O-rings, but Walden machined this one to reinforce the prototype copper head gaskets.
    409 Aluminum Big Block Engine Build Walden Machined O Rings
    Not all the 509 blocks will be machined for O-rings, but Walden machined this one to reinf
  • 409 Aluminum Big Block Engine Build Total Seal Gapless Secondary Rings Sets
    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.
    409 Aluminum Big Block Engine Build Total Seal Gapless Secondary Rings Sets
    Total Seal gapless secondary ring sets were used. The unique deck angle of the 409 require
  • 409 Aluminum Big Block Engine Build Ridge
    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.
    409 Aluminum Big Block Engine Build Ridge
    Note the ridge: Below the ridge is the cylinder bore, above the ridge is the combustion ch
  • 409 Aluminum Big Block Engine Build 409 Piston Geneology
    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.
    409 Aluminum Big Block Engine Build 409 Piston Geneology
    Geneology of the 409 piston: far left is a stocker, the middle shows one of Walden's custo
  • 409 Aluminum Big Block Engine Build Walden Pistons And Eagle Rods
    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.
    409 Aluminum Big Block Engine Build Walden Pistons And Eagle Rods
    This engine received a set of Walden's pistons, with a 10.5:1 CR, and 0.250-inch longer Ea
  • 409 Aluminum Big Block Engine Build Comp Cams Camshaft
    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.
    409 Aluminum Big Block Engine Build Comp Cams Camshaft
    Cam choice is a solid roller, ground by Comp. The 409 cam is the same length as a BBC, but
By Brad Ocock
Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!

*Please enter your username

*Please enter your password

*Please enter your comments
Comments:
Not Registered?Signup Here
(1024 character limit)
Super Chevy