Last month, we started our EG cover car project's engine build by constructing a poor-man's Type R block with RS Machine in Carson, Calif. The block was a GSR casting utilizing the stock crank and rods mated to RS's stock bore Type R replacement pistons. In this installment, we go back to RS to build the cylinder head, with the intention of building a top equal to our Type R doppleganger bottom end.
We began with a bare B16A head casting. The PR3 is the same coveted casting found atop B18C5s or B16Bs. The differences are in the hand-port finish and upgraded valvetrain in the Type R heads but not found in the B16.
Mike Coughtrie (sorry for spelling your name wrong last time, Mike; it was Eddie's fault) lent a very experienced hand for the port work and assembly. The essential differences in the Type R ports are a bowl blend, a valve job, and a casting cleanup. The bowl blend smoothes out the ~90 degree angle at the back of the port to make the transition between the manifold runners and the combustion chamber less restrictive. Mike also performed a valve job that is more aggressive than stock; this maximizes power at the cost of longevity, at least when compared to a stock job. Finally, the casting cleanup is simply taking out the flaws and casting lines inherent in a sand cast head.
Skunk2 Racing answered the call for our valvetrain. We're implementing its Pro Series .5mm oversized and flat-faced valves, dual valve springs, and titanium retainers in our B16 head. Putting the push on the valves are a pair of Skunk's Pro 1 cams which will be spun by a couple of Pro Series adjustable gears. To finish off the Skunk2 ensemble, and direct air into the head, we're also using a 68mm S2 throttle body bolted to a Pro Series intake manifold.
Next time we'll assemble the two halves of the motor and get it hung in our little EG's engine bay. For now, check out the head build and learn something.