Have a 2 part question. I am considering a few mods to my 01 zo6. One is putting a more aggressive cam in the car. My question is will this decrease the longevity of my engine. The other question is this, if I have headers, no cats, h pipe, and after market exhaust on with the cam and tune and intake how much HP can I expect....thanks in advance.

 

As far as motor life I would say it depends on how you drive the car. As for HP I have the same set-up you have but I have stock 241 heads and I put down 412.6RWHP and I think 366RWTQ. You should put down alittle more because of the 243 heads. It has alot to do with you tuner and how big of a cam you put in, big cams will give you good mid and top-end power and a smaller cam will give you good low to mid but die off on the top. My cam is a MS3 236/242 with a .609 lift. Good Luck and let us know the numbers you put down.

 

Generally speaking, the higher the lift the shorter the life of the valve springs. I've heard with lifts in the 600's you won't get much more than 20,000 miles out of a set of springs. If it's a weekend cruiser no big deal but rough for a daily driver.

 

Bump

 

20K would be pushing it too.

Rebuild heads, lifters, valve, valve guilds and replacing springs are a very good idea for a high use car.

Race engines are rebuilt quite often. and measured in hours of use, not miles.

 

Setup will also play a major role. The rocker height will need adjustment to account for more lift, which will minimize valve guide wear. The pushrods should be selected to increase stiffness (larger OD is a major contributor to this). Pushrod stiffness also helps with cam wear, lifter roller wear and overall longevity of the parts in the valve train. Valve spring installation should include measurements of installed height to achieve seat values recommended by the cam manufacturer. If you are looking for lower maintenance, stay with steel retainers. Titanium will wear in time and shoild be inspected periodically. Valve springs are a wear item, no question. The stock valve springs are pretty much the same though so it isn't just aftermarket. I think if you dyno a stock setup with some good miles on it you will find the valve springs are likely not keeping up and in need of replacement. So too with aftermarket more aggressive setups.

I also took some preventative steps when I did mine. I installed a top notch timing set and ported oil pump. I installed the timing chain damper. The crank damper (pulley) is an ATI 10% underdrive (not 25%). My decisions for parts were based on quality of the installed part, how I could improve performance traded against longevity that I felt I could obtain with the part.

 

I think I am probably not going to even mess with it. I think I will just leave it factory, although I don't drive it very often I don't want to have to worry with all the extra stuff and I really don't want to risk my stock engine. If it wasn't bone stock I wouldn't think twice.

 

If your not having a problem, and most engines dont, leaving it stock is best.