I'm building a big block street engine and I have a question about camshafts. I would like to run a roller cam but I'm concerned about their durability versus running a regular solid lifter cam. I drive it about 1500 miles per year and rarely race the thing on the track. What do you think?-Chris Perry, Via e-mail

Chris- This is a good question that I get asked a lot in the course of building engines. As with most everything else, if you select the parts wisely, you will have no problems with a roller cam. Face it, almost all of the production cars in the world run roller cams at this time. Granted they are hydraulic rollers but this was done to lower the maintenance and internal friction of the engine, in addition to increasing its durability. In fact, many of today's engines incorporate many old racers' tricks inside for the sake of power and mileage increases. Most old car guys would flip out if they took apart one of today's high tech mills and saw the razor thin piston rings, lightweight parts and skinny stem valves. It is comforting to know that all of us grass roots racers were on the right track for so many years. For your situation I would say that it is indeed possible to run a roller cam with no problems for this use. There are roller cams and then there are roller cams. What this means is that some grinds will waste springs in 10 blasts down the quarter and some will run forever. All of the cam grinders have wild grinds and wimpy grinds so simply choose one that is a little on the wimpy side. If you study the cam lobe charts you will see that for any given advertised duration they may have 5 lobes with vastly different durations at .050"' and .200n lobe lift. A lobe with more duration at these more relevant lift points is consid¬ered "more square" than a less aggressive design. As the lobe becomes more square, the demands on the valvetrain go up and the durability goes down. If you study the charts and understand this, you should be able to pick a good compromise lobe. Most of the cam catalogs will tell you in the descriptions of a particular cam if it's recommended for the street. You can also look in their circle track sections since these cams are less radical than their drag race cousins. Most circle track guys run many hundreds of miles in an average season so if it holds up there, it will hold up on the street. Really the only thing you should be worried about are the valve springs. As long as they stay strong, things will work out fine. Once the springs start going away, all sorts of problems will start to happen with the rest of the parts. If the springs weaken, the lifter may not be able to follow the lobe correctly and may start to hammer itself apart. Many roller lifter, rocker and pushrod failures can be traced to weak springs. What I like to use are non-exotic material valve springs intended for circle track engines. Generally they can provide the same seat pressure with less open pressure than a drag race spring. They also will hold this load for many more miles than a more brittle drag spring. By definition, a drag engine is a full blast, short duration beast while a circle track or street engine has less peak power in exchange for more durability. As I have said before, there is no free lunch with these things. Basically what I'm saying here is to set your mill up with a bunch of circle track parts and don't worry. If you are concerned about it, buy an on-the-car valve spring tester and check your springs on a regular basis. With all of the material advantages we have today in the valve spring department, it is possible to run rollers on the street with no problems, but you do have to keep an eye on the valve lash. Remember that solids have durability problems too. I'm sure you know many people with "flat lobe" (wiped) solid litter cams. At least a roller will never do that!