318 driver - cam change or not?
Actually, while searching the forum, I found one of your posts from a couple years ago where you basically answered my question above about the differences in duration. It looks like the cam you recommended would be a good budget choice that would be easy on the valve-train. I never realized that advertised duration varied so much between manufacturers. It does look like a more modern grind with faster ramps might be slightly more torquey but at the expense of extra noise and shorter valve-train life. I use my car as a daily driver during nice weather, so giving up durability is not something I want to do. Did you use the Perfomer cam specifically or one of the similar knock-offs? My apologies if I have stepped on your toes. Just trying to learn as much as I can.
Usually, when someone asks about a cam for the STREET, I take them at face value and offer a good STREET recommendation. Whatever that recommendation is, usually will not include a fast rate of lift "modern" grind, because if you drive something on the street either every day, or close to it, you don't want something harsh on the valve train. You don't want something that will have valve train noise "no matter what" you do. A lot of times with those fast rates of lift cams, that's what you end up with.
I look at it like this. No matter "what" cam you choose for "whatever" project, you will leave power on the table. You can run yourself ragged trying to pick one that won't but you'll just take the fun out of it. I try to make recommendations based on what I know about camshafts (admittedly more know a lot more than I) and personal experience. I don't get all the formula books out and try to whip up a bunch of numbers to confuse someone already confused before they ever asked their question here. Besides, "what if" you tell me you have a 9.5:1 engine for example and a mistake was made "somewhere" along the way and you really don't? That means all those numbers and calculations about cylinder pressure and this and that are now incorrect.
No, I much rather like to "ballpark" it because there is more "fudge" room so to speak. Now, were you building a race car for bracket points or the like, then that's a whole different ball game. Then we need to get the burrette out and start measuring cc's.
.....and lastly, it's not about using "MY" recommendation. That part is not even part of the picture. I will say this. It's funny that everybody else's recommendations are pretty much spot on with what I said. Use them as a guide. Want more bump? Go up 2-4 degrees in duration and or tighten the lobe centers from 112 to 108 or do both. Just remember, that when you do that, you are trading off bottom end torque for a mid range/top end charge. With a 318, you need to be careful because you can turn it into a dog real quick on the bottom. That's why I tend to err on the small side with the 318.
