have looked into comp cams, but i dont know much about lumanati vudoo cams or mopar purple cams
All cam's have a duration. The grinders will say this cam has a advertised duration of 300*'s. Not all grinders will rate there cams at the same lift at the valve or tappet rise. Even the same grinder, any of them, will have diferent ways they'll rate cams. Sometimes they'll rate the street cams advertise duration with .006 tappet rise and there race cams with .004 tappet rise and still yet another series cam with .010 tappet rise.
Look closely at the Comp Cams catolog.
Then theres the duration @ .050 and that is where all grinders will aslo rate there cam. It's a leveling feild to which you can make all compersions.
You can also look at both rates and see alittle bit how fast the cam is rising. In general, the fast the cam lifts the valve, the more power you make. Win/win? Mostly, valve spring and the valve train are under more stress and wear out faster.
The larger the cam and/or more power you get out of yur engine, the faster the wearing out of parts, so, a fst lifting rate cam isn't a bad thing on the street.
The MP cams (Purple cam) has an advertised rate only. The way you figure out there duration @ .050 is to multiply the advertised duration by .850.
You'll find the Purple cams to have a fast rise, not overly aggressive.
The Lunati cams show both duration numbers on there web site. This makes it alot easier. They also tend to have more lift than anybody else and take very very good advantage of the larger Chrysler lifter @ .904.
The Comp Ccams XE series cam does not take full advantage of the .904 tappet, nor do the MP cams.
The Comp XE HI-Lift cms and the Voo-Doo cams do come extremely close.
The one thing I do not like about the MoPar cams are there are no split duration cams or high lifting cams in a modertae duration. While this is something I like myself, it is not a must have. Many people will point to a Purple cam as od tech and not worth much, they have never failed to perform as stated or run the time when used as perscribed.
Most people end up saying, "Well, if your getting a cam and paying what you are, wouldn't you get the most cam for your money?"
Theres wisdom in that, IF, the cam fits your build. It's not allways a must to have a max valve lift, max curve under area lifting cam for most builds. It's nice to say your taking full advantage of everything you have under the hood, but it is also not allways needed. Sometimes, it's a bad move to do so.
