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As a retro-fit, Hot Rodders began embracing GM’s LS engine in large numbers around 2006. Ten years ago if you had asked performance parts manufacturers—makers of pistons, camshafts and so on, about their best selling part numbers, they would have told you that seventy percent of their sales were dominated by demand for small-block Chevrolet parts. Today we are told that seventy percent of aftermarket camshafts are developed for the GM LS engine.
Introduced in 1997, the LS enjoyed elevated stature by its admirable power and efficiency compared with its forebear, the venerable small-block. Its long, slender cathedral induction ports generated excellent air speed particularly at low engine speeds, and for some hot rodders they could scarcely have been happier. But others, particularly racers, with greater power needs in mind wanted substantially fewer neuroses. The chief trouble was the skirted block with its semi-sealed compartments—four separate crankcase bays—beneath the cylinders, which caused woeful windage troubles at higher engine speeds, thus significant power losses at the top end. This is in no way criticism of GM’s fine product. As Dart development engineer Tony McAfee is quick to tell you “GM’s priority, I imagine, was to get a pick-up truck down the highway at 70mph, and this the LS does admirably.” But the racers’ requirements are something other—adding twin turbochargers and an inch of valve lift to obtain 1,000hp would require a substantial redesign.