Head Flow We've tested the L92 port before on a different flow bench and our published numbers are slightly higher than the ones provided by GM below. The GM tests were performed with a 4.065-inch bore plate. Valve Lift Intake LS3 Exhaust (L92) Intake CNC Exhaust LS3 0.200 151 111 150 105 0.300 208 152 222 140 0.400 256 174 260 168 0.500 294 183 298 190 0.600 316 189 332 201 Engine Size Bore Stroke Block Type LS1/LS6 346(5.7L) 3.90 3.62 aluminum LQ4/LQ9 364(6.0L) 4.00 3.62 iron LS2/LS3 376(6.2L) 4.06 3.62 aluminum LS7 427(7.0L) 4.125 4.00 aluminum LS3 Cam Specs Camshaft Duration AT 0.050 Lift (Inches) Lobe-Separation Angle (LSA) LS3, intake 204 0.551 117 PN 12603844, exhaust 211 0.522 GMPP Hot cam, intake 218 0.525 112 PN 88958733, exhaust 227 0.525 Parts And Prices Part PN Source Price Engine preluber PL40 Engine Quest $35.00 GM LS3 6.2L 19201992 GMPD $6,446.96 GM muscle car oil pan kit 19212593 GMPD $125.80 GM harmonic balancer 12620556 GMPD $103.19 GM Y-body FEAD 19155067 Scoggin-Dickey $825.85 GM LS3 controller kit 19201861 GMPD $1,506.39 Edelbrock LS retrofit kit 6758 Summit Racing $879.84 McLeod LS flywheel 460535 Summit Racing $425.39 *GM Parts Direct A Brief History of the Production LS Family It all started with the LS1 in the then-stupendous '97 Corvette. The engine was like nothing we'd seen before with all the go-fast theories applied from the factory. The problem, if you could call it that, was the less-than-big 3.90-inch bore that required slightly smaller valves (2.00/1.55) than we were used to. It is a great engine, but at the time, you had to part-out a '98 Camaro or said Corvette to get your hands on a used one. In 1999, the 4.8L and 5.3L LS engines were used in GM trucks and vans, opening the door for LS-hungry parts swappers like yourself to add LS power to the old Chevelle. Since we all wanted more power, guys were sleeving and boring these engines toward the magical 4.00 mark, often with disastrous results. In 2001, the iron LQ4/LQ9 6.0L quietly appeared in big SUVs with a 4.00-inch bore, but few seemed to recognize the potential. It wasn't until the LS2 appeared in the '05 Corvette that the combination of a 4.00-inch bore and LS1/LS6 heads was mixed for a factory 400 hp. It was a really big deal at the time. To feed fatter trucks and larger displacements, GM designed another head dubbed the L92. It used the rectangular ports you see here. By 2008, big trucks like the Escalade and Yukon Denali and Corvettes were all using an even larger version of the LS called the L92/LS3. It has a 4.065-inch bore and the L92 port designs, giving it great factory numbers like 436 hp and 428 lb-ft in the '08 Corvette. There are also supercharged versions of this engine in the Cadillac CTS-V and 638hp ZR1 Corvette. Since you can't have a truck out-gunning a Vette, the 7.0L LS7 appeared in 2008 with a 4.125 bore and went way over the top in the N/A 505hp Z06 Corvette. The LS7 is currently state of the art with a 4.125-inch bore and special LS7 12-degree heads that flow more than 350 cfm at 0.700 valve lift. We haven't seen a supercharged version of the LS7 yet but can imagine its potential. Is an 800hp Corvette in the future? Would you like meatballs with that? Once again, do not hook this up to your barbecue. SOURCES EngineQuest 2580 N. Commerce St North Las Vegas NV 89030 800-416-8628 www.aaeq.net GM Parts Direct Greensboro NC 800-316-8634 www.gmpartsdirect.com GM Performance Parts P.O. Box 33170 Detroit MI 48232 800-577-6888 www.gmperformanceparts.com « | 1 | 2 | 3 | View Full Article By Douglas R. Glad Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!