True Vintage Tri-Power - Rod & Custom Magazine

True Vintage Tri-Power - Part 1: Behind The Scenes At SO-MO Speed Shop

The venerable tri-power is without question a staple in hot rodding. Nothing looks better perched atop a vintage mill than a trio of double barrels. But at the same time, nothing runs worse than a tri-carbed engine when all the variables of that “3x2” equation don’t add up. And more often than not, it’s that miscomputed factor that forces many a tri-power to be set on the shelves rather than the V-8 it was really intended for.

1108rc 01 True Vintage Tri Power+350 Engine

None of us like to be hassled, especially when it comes to maintaining the driveability of our cars. Ultimately, that’s what dictates going with a simple, tried-and-true four-barrel over a multi-carb setup—that, and the difference in price, of course. But oftentimes, when cost isn’t a factor to begin with, there are those who will still take the easy road just because they don’t want that supposed hassle inherit with traditional tri-powers. In reality, you can have cake and eat it too—without napkins!

 1108rc 02 True Vintage Tri Power+pre Mod Motor As you’re about to see, our tri-power feature will develop into two segments, the first obviously being the initial setup and assembly performed at SO-MO Speed Shop. But, what good’s a functional intake system if it doesn’t have a platform in which to function on?! That’s where this 5.7L 350 comes in—and yes, along with everything else in the “top end” category, those center bolt heads will make way for a set of pre-’87 iron heads.

For the very same reason many of those popular four-barrel carburetors are so reliable—factory preset, pretuned, and ready to go—you can now run a true vintage tri-power without all the hassles. And we’re not talking electronic fuel injection in disguise, either (although that is not only a viable option, it’s an efficient one). We’re talking real Stromberg 97s, an Offenhauser three-deuce intake, and copper fuel lines with an old-fashioned glass bowl filter. The difference between a SO-MO Speed Shop setup and all the others—it’s already been professionally assembled, tuned, and test-run (on a dyno’d engine); all you do is bolt it on, hook it up, and go. Simple as that.

Believe it or not, these induction systems are not mass produced in some huge, zillion-dollar facility by some big parts conglomerate—they’re done the old-fashioned way, by a small family owned, family run speed shop … in other words, real-world hot rodders just like most of us. Unlike most of us, however, SO-MO Speed Shop has perfected the art of old-school intake systems—and not just tri-power, either, as they offer four- and six-deuce setups for a number of applications. Their Widow Maker series utilizes the finest components available today, such as the aforementioned Genuine Stromberg carburetors (as well as Rochesters) and Offenhauser intake manifolds (straight from Offy’s foundry), and are custom built to each customer’s specifications. And for the ultimate in worry-free performance, SO-MO gladly engine-tests their systems, as well as providing each individual unit with its own serial number, which is kept in a customer database for future reference.

1108rc 03 True Vintage Tri Power+so Mo Speed Shop Assmebly Room All Widow Maker builds take place in SO-MO Speed Shop’s sanitary assembly room—not some huge factory. Initially, all parts for the specific projects are laid out on the bench and checked off the project build list made specific to each customer’s order. All parts are visually inspected for any functionality issues or possible damage caused during shipping.

So, instead of piecing together that vintage multi-carb intake system with a hodgepodge of various parts—and keep your fingers crossed everything works in unison—why not leave it up to someone who’s been there and done that? I don’t know about you, but my DIY pride quickly disappears when I’m stuck on the side of the road due to mechanical failure on my behalf. I may be able to rebuild and tune a single carburetor with occasional good luck, but for the most part, if there’s more than one air cleaner involved, my money’s better spent on someone else’s time and experience so that I can ultimately spend more time behind the wheel, not under the hood!

Tip:

1108rc 04 True Vintage Tri Power+assembly Table

Remember that progressive style linkages must have final adjustments based on carburetors that have been idle balanced on your specific engine. It is recommended that all synchronization and adjustments be made without the throttle and transmission cables connected. Adjust the carburetors first and let them dictate the position of the cables and brackets. SO-MO Speed Shop sets the carburetors and linkage at a good base point. The balanced carburetors dictate the linkage synchronization adjustment settings. Though nothing beats a dyno for tuning, you can balance your carburetors with a little patience and a Uni-syn sync tool. Once all adjustments are finalized, it is strongly recommended to apply medium strength thread locker to all link arm set screws to ensure they do not vibrate loose.