When contemplating an engine project, there are many reasons to consider starting with a brand-new block. Sometimes the move is predicated on a power threshold that demands new metal in beefy aftermarket form, though other build goals can play just as vital a role in this choice. In the case of our slant-six-equipped project '68 Valiant, we decided from the onset to take the path less traveled, and opt out of the typical small-block swap in favor of big-block power. Taking things a step further, the basis of the build would be Indy's aluminum Maxx block. While this might seem like the realm of the exotic, as Indy's Ken Lazari tells us: "Believe it or not, it is not much over about a $2,000 upgrade to any engine, so it's not out of this world as far as extra cost, and that's why we build a lot of them. These things are nose-heavy to begin with and it takes the weight off the car, it improves cooling, and, of course, you won't end up splitting it five years from now-it's going to be in there for a long time. If you want a car that's going to handle and want to take the weight off the nose and beat on it hard, the Indy Maxx block is a good option."
Want big Mopar power in a lightweight package? The Indy Maxx low-deck Wedge block that for
The Maxx block is cast in the United States in the state of Ohio and is fully water jacketed, with siamesed cylinders. Since the machining to the bare casting is all done at Indy Cylinder Head, the block is available in a wide range of configurations, including both tall- and short-deck Wedge or Hemi versions. OEM Mopar big-blocks came in two distinct flavors, the low-deck "B" engine with a factory deck height of 9.98 inches, or the "RB" with a deck height of 10.725 inches. In the tight confines of an A-Body engine compartment such as our '68 Valiant's, the compact low-deck B-engine is definitely an easier fit.
For our engine project we selected the low-deck Wedge Maxx engine, which, unlike the factory low-deck engines, features the 440-sized 2.750-inch mains, rather than the OEM 2.625-inch dimension, for a broader range of crankshaft choices. Speaking of mains, the reinforced bulkheads of the Maxx block's bottom end feature Indy's billet caps with cross-bolting at all five mains, rather than just the center three as in factory Hemi blocks. As Lazari details: "When the block was designed, we strived to make that thing lightweight, strong, and stable; it's got to be stable. That block is 133 pounds ready to go." Major revisions of the lubrication system are also incorporated into the block, with priority main oiling and a unique oil pump pickup arrangement routing oil from an external line to feed a standard big-block Mopar-style oil pump from a passage at the front of the block. This clever setup provides much needed internal clearance for large stroker cranks, a problem area with the production internal pickup. The block also has provisions in the valley to supply oil feed lines to bosses providing top end oiling in the OEM deck location, rather than requiring external lines.
A look at the Maxx block from below reveals the massive bottom-end structure of the Maxx.
|By The NumbersIndy 500 Mopar Wedge Short-Block
||Indy Maxx aluminum
||Mahle Clevite 1795V
||Mahle Clevite 537HN
||Eagle 6.76-inch H-beam
||Diamond forged dish
||Total Seal 1/16, 1/16, 3/16 inch
||COMP solid flat tappet
||245/251 degrees at .050
The Maxx block is cast in the United States, and machined at Indy in a variety of configur
For a displacement of 500 ci with the 4.375-inch bores, an Eagle 4.150-inch stroke crank w
Rounding out the internal assembly are a set of Diamond custom pistons to fill the bores,