Related Photo Galleries
As we mentioned earlier in this report, we elected to forego 1.6-ratio rocker arms and use Probe’s 1.8 ratio, aluminum, 7⁄16-inch stud-mount arms. With the hydraulic-roller cams, the rockers are zero-lash; no adjustment is necessary once the rollers are centered on the valve tips, and the 8.500-inch-long, 3⁄8-inch pushrods can barely be twisted between the thumb and index fingers. A set of Comp’s hydraulic-roller lifters (PN 8931-16; $529.95) actuate the pushrods. This move to 1.8 rockers was made in an effort to extend the engine’s rev range, and maximize its power potential, with and without a nitrous shot. With the 1.8s, the cam’s lift jumps to .646-inch on the intake side and a generous 0.670-inch at the exhaust.