How to install a surveillance cam?

What would a shop want to install a cam and springs?

• on a 3.8l v6 pushrod ohv engine with (i believe are) hydraulic lifters, what could be a rough estimate to what they would want to install a cam and new valve springs? oh, and while your at it, would you believe a high lift cam gould bring a 200hp engine to 250hp? i saw it on a forum where some guy used a desktop dyno program and changed only the cam #s, everything else stock, and saw that a cam could be a 50hp upgrade... i dont buy it considering a stock supercharger is 40hp... what about you?

• Answer:

  Computer simulated dyno programs are far from reliable. You can find 15 horsepower in your stock cam simply by reducing lifter pre-load by about .025 You'll also see a big improvement in driveability, milage, and RPM capability. You can gain 50 HP out of it with a cam change. But you will not do that with another Hydraulic cam unless you shim the plunger travel of the lifters so that they can only collapse about .015. Otherwise, the bigger hydraulic cam it would take for you to make those kind of numbers would have to happen beyond any RPM where an unmodified hydraulic lifter would ever allow the engine to RPM to so that you could see those numbers. In the meantime, the amount of power it would knock out of the engine at any useable street RPM levels would be etrocious. Therefore, a big hydraulic cam would be a TOTAL performance loss for you across the entire RPM range. After any cam change, you would also have to do some custom computer tuning of the fuel curve and some of the timing tables. A new cam will not be a plug and play deal for you. I'd leave it alone. Maybe advance the factory cam 2 degrees with some advance bushings, but as for replacing the cam, your gains will be nowhere near the justification of the expense or the exercise. Until you put a solid roller cam in there, the numbers you are expecting are not going to happen. Even then, you would have to buy an adjustable shaft mount rocker arm system and some 3/8 pushrods to go with a solid roller cam to make it physically work. Then you would be looking at some big solid roller springs, retainers and valve locks. All of that would be about a $2200 investment before any labor or computer work, too. Leave it alone.