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Moving Up to a Hydraulic Roller Cam

One of the quickest ways to gain a significant performance boost is to move up to a hydraulic roller camshaft. This conversion gives you a lot of advantages over a standard hydraulic cam.

The advantages of a roller cam include: no need to break-in the cam on initial startup, the lifters can be reused if you change cams, the open and close ramps of the lobes are faster, giving you more torque and horsepower for any given grind, roller cams wear at a fraction of the rate of standard cams, and roller cams can use the latest blends of motor oil with out the zinc, so no additives are needed.

A few things are different about a roller cam installation. A standard cam is ground in a way that causes the lifters to rotate during operation to minimize wear. This design causes the cam stay in place by itself as the engine turns. The roller cam design does not need to rotate the lifters, so it will “float” in place during operation.

To keep the roller cam from moving too much, you need to use a cam button between the cam cover and the cam gear to hold it in place, and a Torrington bearing behind the cam gear to keep the cam gear from damaging the block. You will need to set a camshaft end play by using shim washers (similar to setting crankshaft end play). Lastly, you need to make sure that your distributor drive gear on the cam, and the drive gear on your distributor are compatible.

Roller cams are hardened steel, and if mated to a soft iron distributor gear, it would wear out the distributor gear quickly. Most cam makers press on a soft iron gear on the camshaft at the factory, so in many cases you need to do nothing. However, if your roller cam has a hardened gear, the cam manufacturer usually sells a matching hardened steel distributor gear for you to use.

If you are retrofitting an older engine that did not use a roller cam from the factory, you will need to use a retro fit roller cam and retro fit roller cam lifters. These parts have the correct geometry to go into an older engine and have their own unique part numbers. Also, you will need to use shorter pushrods for a roller cam, and the manufacturer will have the correct length ready for you. If your engine is newer and has a roller cam from the factory, you will use a roller cam and lifters that are designed as direct replacements. Roller cams will work with any rocker arm design.

Going to a roller cam upgrade is one of those few times where you can really tell the difference it makes when you drive. Roller cams are more expensive, but if you can convince your customer to come up with a few extra bucks, it will really be worth the investment.

 – Tech Tip courtesy of Summit Racing