The Quad 4 was a 4-cylinder, 2.3 liter engine GM designed in the late 80's and produced 180-190 hp depending on the level of tune. Impressive numbers on paper when the 5.7 liter V8 engine in the Camaro was barely making 200 hp.
However the reliability problems (head gasket failures, etc) were pretty common for this motor and gave it a bad reputation.
Was it a fundamentally flawed design? Or did GM corner-cut in places that they shouldn't have? Can these motors be made reliable with readily available aftermarket parts?