Caught under test in a handful of Pontiac 6000STE’s and five-speed Fieros, was this experimental 2.5-liter OHC four-cylinder engine.  The word in Detroit was that this CPC powerplant was a heavily modified Tech4 Iron Duke that easily produced 145 bhp w/ a 9.3:1 compression ratio and larger than stock throttle-body injection. Mated to a stock … Continue reading 1988: Was Pontiac’s Experimental OHC 2.5 liter four, an Alternative to the Quad 4?