CNC-Ported Gen V LT1 Cylinder Heads

View Full Gallery

The 2014 Corvette Stingray has barely been on the street for a week, and Chevrolet’s new bad-body Gen V SBC has only been out a few weeks longer than that. Never the less, our good friends in the aftermarket industry have been hard at work. A few early sets of LT1 cylinder heads became available, and testing was underway. Step one was, of course, establishing a firm baseline for GM’s new 12.5/12-degree head.

As you can see from the first two graphs (courtesy of Lingenfelter Performance), the LT1 appears to be lacking in exhaust flow compared to the LS3/L92 cylinder head. But it really shines is on the intake side, as the .550 to .700-inch lift gains are substantial–peaking around 330cfm. While the stock (.551/.524-inch lift) cam will hardly take advantage, high-lift aftermarket cams should provide a significant bump in power. The good folks at LPE also verified that there is a significant difference between the two 6.2L (LT1 and L86) castings versus the 5.3L L83–over 50cfm in fact.

Of course Lingenfelter isn’t the only game in town, though. Late Model Racecraft in Houston, Texas has been one of the fiercest Corvette builders as of late. And they weren’t about to take this one lying down. After doing its own baseline evaluation, the crew got to work on a CNC program. In the initial iteration LMR has opened the runners up slightly–312cc intake and 112cc exhaust with a 61cc chamber. This has accounted for some impressive flow numbers that peak at 345cfm at .800-inch lift on the intake and 260cfm on the exhaust. Stay tuned for more updates as this develops. The race is on!

LMR_CNC_LT1_Gen_V_Cylinder_Heads 5/5

Baseline

Lift Intake Exhaust
.200 134 120
.300 204 164
.400 258 193
.500 291 204
.600 285 208
.650 291 210

CNC Ported

Lift Intake Exhaust
.200 137 116
.300 208 154
.400 270 197
.500 310 228
.600 331 245
.650 335 252
.700 340 257
.800 345 260


*Flowed on 4.060-inch bore at 28-in. of water with an untouched port and valve job

MORE PHOTOS

VIEW FULL GALLERY

COMMENTS

TO TOP