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Chevy LT1 Engine Build - LT1 2-Go...Almost

Despite Parts Like Opti-Spark, A Shaft-Driven Waterpump, A 58mm Throttle Body, And One-Piece Gaskets, This Is Still A Small-Block!

Photography by Roy Landgrave, Terry Cole

When it comes to raw horsepower and stump-pulling torque, there's no substitute for cubic inches! Every Bow-Tie enthusiast with the slightest drop of Chevy orange flowing in his veins knows that. But the days of factory muscle sporting anything more menacing than a 350-inch small-block are long gone. If you want a big-block, you'll have to buy a Suburban or one-ton pickup to get it. Even then, the fat Rat is more of an embarrassment than an inspiration when it comes to performance. But the little mouse known as the LT1 has kept the rebel flag waving high ever since its introduction in the C4 Corvette, and later in the fourth-generation Z28. With an easily attainable 350 horsepower, this was enough to keep most enthusiasts happy. Problem is, we're not your average enthusiast. We're go-fast fanatics, and when it comes to horsepower, we want more, more, more! Truth is, we can't get enough.

But the late-model LT1 has its limitations. Last month when we kicked off this story on building a bigger and enhanced version of the final rendition of Chevy's legendary small-block (sans the special edition LT4, of course), our focus was on strengthening the block and improving the reciprocating assembly. In addition to adding splayed billet four-bolt main caps, we plugged Manley forged H-beam rods between SRP forged pistons and an ultra-trick Cola 4340 forged crank. With this much strength spinning inside the iron case, we felt assured that there'd be no problems building some "really stout" power. As with these endurance improvements, upgrading the efficiency side of things was a natural, too. To emphasize that, we installed a set of highly modified Airflow Research cylinder heads and a carved-out LT1 intake manifold. For valve operation, an intricate assemblage of Crane components was chosen to efficiently open and close the oversize valves. And holding it all together is the responsibility of industry standard ARP fasteners. Again, a perfect complement of parts!

Last month we focused on the brawn and finesse of our powerplant; in this month's segment we cover the installation of some of the peripheral items, mostly those things that differ from a conventional ages-old small-block, such as the Opti-spark ignition and the direct-drive waterpump. While bolting these pieces together might seem mundane and simple, the fact is that the modern mouse has enough subtle differences that if you don't pay attention to them, they could cause catastrophic failure down the road. And, since our plan is to add an ATI Procharger before stepping up to the dyno, we felt it warranted taking the time to be sure everything was bolted in place correctly. That being said, here's part two of our high-output 383 LT1 buildup. Stay tuned next month when we'll unleash this beast on the Vrbancic Brother's dyno, and watch as electronic tuning wizard Craig Railsback (of Blower Drive Service fame) pushes the buttons on his PC to make the Speed Pro C-Com fuel management system do its job in helping our modern mouse spin the dyno's power and torque needles to a level we'll all be impressed with.

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