Mahle Clevite bearings were used throughout the assembly of the bottom end, with the main
Fillin' The Bottom
Although the Maxx block can easily swallow bore sizes of over 4.500 inches, the plan for the short-block was to build to a displacement of 500 ci via 4.375-inch bores and the popular 4.125-inch stroke. The arm is an Eagle forged stroker crank, a common off-the-shelf piece, treated to Eagle's ESP Armor process. Lazari spoke highly of the Armor treatment: "It is slick, I can tell you that. It mic'ed out really good. The extra treatment makes the surface really good." The crankshaft rides on Mahle Clevite 1795V main bearings and the assembly is secured with top quality ARP hardware. Working in concert with the Eagle crank are a set of 6.760-inch Eagle H-beam rods using a standard Mopar-style big end and a big-block Chevy spec .990-inch wristpin bore. This configuration is an off-the-shelf item from Eagle. Rod bearings are also Mahle Clevite, PN 527HN, run at .003-inch clearance.
Speaking of clearances, Lazari explains: "We set it up like a race engine; we run about .0035 inch or even as much as .0004 inch on the mains, requiring a 20-50 weight oil." The pistons are custom from Diamond, with a substantial dish to get the compression down with the large displacement and the Mopar's relatively compact chambers." Lazari continued, "We went with Teflon coating on the piston skirts to reduce friction, and used a .200-inch wall pin. The rings are a 1/16-, 1/16-, 3/16-inch conventional moly set from Total Seal; it's all heavy-duty stuff. The only thing about the combination is that you are running a short piston. It took a little while, but it sealed up pretty good, and it's not noisy either; that's what I always worry about with something like that, but it's pretty quiet."
The bottom end is closed with a Moroso oil pan sporting a Mopar Performance stroker-spec windage tray sandwiched between the pan and the block. The pan was modified for the external pickup by Indy, using their rear-mounted static pickup kit, routing the oil through a -12 AN fitting. Lazari remarked: "That line might look like it has goofy angles, but believe me, having put enough of these into cars, it clears the K-member and any type of Mopar suspension; it clears everything."
Keeping the vital fluids in check are a Moroso oil pan and a Mopar Performance windage tra
With the reciprocating assembly handled, the camshaft represented the next key element of the parts selection process. Weighing the alternatives, Lazari decided that a solid flat-tappet would offer the best balance of longevity and performance. The COMP Cams grind specs to 245/251 degrees duration at .050-inch tappet rise, with .371/.382-inch lobe lift, and was ground on a lobe separation angle of 108 degrees. Lazari detailed: "We put a solid flat-tappet in with the plasma nitride hardening, so there's no worrying about it wearing out. The specs are pretty modest. With a motor like this you can put 280 degrees duration [at .050] in it, and it will love it. But for a street application, you don't really want to drive it around like that. It will load up, it won't be responsive, and it will want a lot of converter in the trans. I kept shrinking the cam timing down until the point where any smaller would lose a lot of power. I took it down to the bare minimum; that's what it boils down to. With 5 degrees less duration it might have lost 50 hp."
With the trick aluminum Indy block, the entire engine package will tip the scales considerably less than an iron small-block, yet the power and torque of a 500-inch big-block will not go unnoticed. The block alone represents over a 100-pound savings compared to a production block, and nearly double that compared to some aftermarket iron block variants. Indy relates they have had these blocks in supercharged and turbocharged applications up to 2,500 hp. Lazari tells us that at a street power level, the bottom end will maintain its dimensions and last just about forever. Reliability and performance at substantially fewer pounds per horsepower are convincing reasons to consider an aluminum block as a basis for your build.
Next month, we'll take a look at the cylinder heads and induction, and put the 500ci Indy Maxx Wedge on the dyno. Stay with us!
Eagle's ESP Armor
Looking at an Eagle crankshaft with their ESP Armor finish, what becomes immediately evident is that the surface is as smooth and shiny as chrome. ESP Armor is not a coating, however, nor is it an electroplating process, but is rather an exclusive surface finishing process that imparts the signature mirror-like surface. The process does not actually change the part's dimensions, but it does provide quantifiable performance advantages. According to Eagle, the ultraslick journal surfaces make more effective use of the thin film of oil between the bearing and crank, for added protection against failure at this critical area. Since the treatment covers the entire surface of the crank, oil shedding is reduced for potential power gains from reduced windage. Add in greatly improved corrosion and crack resistance, and you have a winning combination. Dyno testing from Eagle and testimonials from their customers cite significant power gains. For the details, visit www.eagle-rods.com.
As assembled, the external oil system fits tightly to the block, and will clear in popular
With real street functionality as a key goal of the build, the camshaft specifications wer
The basic short-block was completed by degreeing the COMP cam to 106 degrees, 2 degrees ad