400ci Dart Aluminum Small Block Engine Build - Aluma-Mouse

All this is exactly what famed Detroit race car fabricator Ron Fournier was thinking when he went shopping for a new engine for his personal, handbuilt track roadster. Fournier designed his 1,600-pound bomb as a tribute to the great track roadsters of the '50s, and also as a sort of street-legal sprint car-he likes to hot-lap the roadster at local dirt tracks when he gets the chance. An all-aluminum small-block was the perfect choice for his rod, so he called his buddies at Dart Machinery in nearby Troy, Michigan, leading purveyors of aluminum Chevy blocks. The build for Fournier's engine was performed in-house at Dart's engine shop by Jeff Lake and Tony McAfee, the company's Pro Stock specialists.

Though the piece is cast in aluminum rather than iron, the Dart block bears some dimensional similarities to the Chevy-based Olds Rocket block originally marketed by GM Performance Parts. So while the Dart casting is somewhat non-standard compared to a conventional SBC, parts channels are still comfortably wide. To accommodate big stroker cranks, the oil pain rails have been spread outboard 0.400-inch on each side, while the camshaft is raised 0.391-inch in the block, rolling on big-block Chevy journals. Thus configured, the casting can accept bores of up to 4.185 inches and strokes of up to 4.125 inches, for as much as 454 ci. While Dart's block is most typically used in oval racing, the casting was designed from the start to support street hardware, including a mechanical fuel pump, a conventional distributor, and a wet-sump oil system. There are a few wrinkles involved in setting up the Dart block for road use, however, and we'll cover them here.

Among his other duties at Dart, McAfee heads the company's advanced wet-flow bench research program, where he has developed some firm convictions about what works and what doesn't for a given combination. "This is the smallest port we offer and I would say it's way underestimated," he says. "The 180 has the best overall performance for the street and it's absolutely ideal for hydraulic roller cams. For power peaks below around 6,400 rpm and displacements up to 400 inches, this is the head you want." To finish off the conservative, high-velocity airflow combination, a 650-cfm Demon carburetor and a dual-plane Dart intake manifold were selected.

Comp Cams supplied the stick, a hydraulic roller grind, on its 12-000-9 core. Lobe lift is 0.363-inch on the intake and 0.361-inch on the exhaust, while intake and exhaust duration at 0.050-inch lift are 236 and 242 degrees, respectively. Lobe separation angle is 110 degrees and the cam was installed on the 108 degree intake centerline. With Dart 1.6:1 rocker arms, net lift works out to 0.581-inch on the intake and 0.577-inch on the exhaust. So while the lightweight block requires a non-catalog camshaft, the cam timing used here is fairly conventional small-block fare.

Due to the wider pan rails, an OE-style oil pan won't fit. But not to worry; pans are readily available off the shelf from Moroso and others, in both wet- and dry-sump varieties. If you've opted for a wet-sump setup with a standard Chevy oil pump like this engine, you'll need to use a big-block oil pump shaft to compensate for the elevated camshaft centerline. A remote oil filter is also required since the block lacks a filter pad. And if you're running a block-mounted mechanical fuel pump, you'll need a 0.200-inch-longer fuel pump shaft, available from Dart. Finally, you'll need to machine a 0.391-inch spacer to slip between the intake manifold and distributor-again, to adjust for the increased cam height-or you can simply use one of the many adjustable-sleeve distributors on the market.

Quick Notes

What is it
400ci build with a Dart aluminum block

Bottom Line
It's a reliable package that looks impressive under any hood

Cost (APPROX)
$11,390