Quick! What are the first three things you typically do to your engine when you want to increase power? First on the list is usually an intake and carb swap, followed by headers and dual exhaust. Some things never change, right? Number three on the list is typically a cam change, and thanks to Crane Cams, number three has a new twist.
Roller cams are nothing new-Clay Smith was grinding them in the '50s, and they're so common today that most new cars actually come equipped with hydraulic rollers from the factory. And as your Chevy and Ford buddies have probably been bragging for years, they've made their way into the aftermarket.
For the first time, it's as easy to install a hydraulic roller cam in your LA, B/RB, and Hemi engine as it is a standard hydraulic or solid lifter cam. Maybe easier! Why it's taken a cam company this long to come out with a hydraulic roller cam for Mopars is beyond us, but fortunately Crane has stepped up and done it.
Solid roller Mopar cams have been on the market for years, but unless you're a die-hard maintenance freak, the thought of putting a solid lifter cam-either roller or flat tappet-in your engine wasn't the best of ideas. And since you have better things to do than reset valve lash every week, you stick to a maintenance-free hydraulic lifter cam.
The new generation 318 and 360 Magnum motors feature hydraulic roller cams, but Magnum roller lifters are longer, so the Magnum block's lifter bore is deeper. Also, the Magnum block has a provision to bolt down the spider plate that retains the roller lifters and keeps them from turning in their bore. So, it isn't just a matter of using, or even shortening, stock Magnum lifters. Crane had to design application-specific hydraulic roller lifters for Mopars.
Then why go with a roller cam in the first place? There are two main advantages: First, a roller lifter takes away the friction between the cam lobe and the face of the lifter. Less friction inside your engine always equals more power, not to mention longer life. Second, because there is a roller bearing riding on the surface of the cam, rather than a flat face with a square edge to dig into the cam lobe, the lobe of the cam can be given a much more aggressive profile. A faster lift allows the valve to open and close much quicker, and more importantly, be held open much longer than a conventional flat tappet cam's profile. What you get is something between full-race roller and mild hydraulic, which is good for a wider power band, cooler engine oil temp, and longer engine life. It really is all the comfort and convenience of old flat tappet hydraulic lifters (drop them in and forget about them) with the performance, power, and lower friction of a roller.
Installing one of Crane's roller lifter cams was almost easier than installing a flat-tappet. It may actually be easier. With a roller cam, you don't coat the lobes with any type of break-in lube-regular motor oil is simply poured onto the cam lobes as the cam is installed. As for the lifters themselves, they're simply dropped in their holes and the pushrods are set in place on top of them, just like a flat tappet. As for break in, there really isn't any need, and the chances of wiping out a cam lobe are gone, due to the roller bearing riding on the cam's lobe.
While a roller bumpstick is obviously more expensive than a typical hydraulic cam (more moving parts, precision machining, and all that), the benefits are worth the extra cost.
Jon Davis and Mike Seargent...
Jon Davis and Mike Seargent of JD Rod Services in Hartford City, Indiana, handled the installation of Crane's hydraulic roller cam in this '95 Dakota truck running a 340 bottom end with Magnum heads. The installation of the cam is the same, regardless of whether you're using Magnum heads or LA heads. Crane now makes hydraulic roller cams for LA, B/RB, and Hemi engines. We left the engine in the vehicle for the swap. Begin by removing the valve covers, intake, and everything off the front of the motor.
Here, Jon and Mike are removing...
Here, Jon and Mike are removing the radiator to gain access to the front of the block. A nice tip (not visible) is to duct tape an old pizza box to the front of the radiator to protect it during removal.
Here, Mike and Jon are removing...
Here, Mike and Jon are removing the valvetrain. It's not critical that the rockers be kept in the same order, but it never hurts.
Here's the object of our attention...
Here's the object of our attention (affection?)-Crane's hydraulic roller cam and lifters, ready to go in.
Always be careful to slide...
Always be careful to slide a new cam in squarely, and slowly. Also, note the absence of any type of break-in lube on the roller's lobes, as per the instructions.
All the clutter is out of...
All the clutter is out of the way. Again, these are Magnum heads (as evidenced by the stud-mounted rockers), but the procedure is basically the same for all the Mopar engines.