Chrysler 331 Hemi Engine - An Aftermarket Inferno

Over the last two months, we've been covering the buildup of a Chrysler 331 Hemi, from the machining process to the final assembly of the valvetrain and related components. What we haven't covered, however, are all the bolt-on accessories that are now available for the early Hemis that make building a reliable engine that much more possible. It shouldn't come as a surprise to most hot rodders that there is a healthy aftermarket industry catering to keeping the Fire Power lit, ranging from transmission adapters to fuel-injection units to conversion kits for a number of problematic areas when it comes to these engines.

One such problem area we covered last time was the installation of the late Mopar high-volume oil pump. This makes for not only an upgrade to a high-volume system, but also allows us to find a replacement oil pump at most automotive parts houses if the need should arise. With the addition of a modern, spin-on oil filter replacing that old paper element type, you're left with a completely modern oiling system.

Another problem area that has been tackled by the aftermarket and embraced in our Hemi build is in regards to the stock water pump and timing cover. Originally, the stock water pump and timing cover was a heavy, two-piece, cast-iron design that incorporated many items that would typically be cast aside by today's hot rodders-such as the transmission cooler and fuel pump. Simplifying the entire ordeal is accomplished using a timing cover adapter, such as one from Hot Heads that mates a readily available small-block Chevy water pump to the front of the early Hemi block and replaces the entire original front cover. The only drawback is the lack of a provision for a stock mechanical fuel pump and the fact that a short-snout 354-style cam must be used. Other than that, the entire timing cover is a bolt-on deal.

Using a small-block Chevy water pump has other advantages, as well, especially when it comes to mounting accessories. The few accessories available back in the early '50s all mounted off either the stock intake manifold, front cover, or both. By removing these items, you're also removing many of the pick-up points used by the stock brackets. However, a number of companies-Bill's Hot Rod Company, available from Speedway Motors, for example-have bracket kits designed to locate off the upper small-block Chevy water pump bolts that make it much simpler when it comes to hanging any accessories off the front of the motor. While not a direct bolt-on for the Hemi, it does use the upper water pump bolts as one mounting point, so it seemed only logical that it would serve as a good foundation for mounting the accessories. A number of other upgrades have also been made in various areas relating to the early Hemi, such as the adaptation of late Mopar harmonic balancers and the availability of multiple V-belt pulleys to accommodate those added accessories.

While building a vintage engine can have its ups and downs, today's vast aftermarket industry makes it easier than ever to build a bulletproof engine that is as reliable as any crate motor out there. Just remember that if you can't find something that applies to your particular project, it doesn't mean it doesn't exist, but sometimes it is necessary to think outside the box.