...and I wouldn't recommend them for a street car. If you look at the catalog, you'll see that they require extra oiling, which usually means oiling by the way of an EDM lifter. Lobes with this kind of aggression need different spring requirements and probably just won't have the longevity that you would want for a street car.
Also keep in mind that just because it doesn't say ".875 lifter" somewhere in the lobe description, it doesn't mean you can't use it on a Ford. As a matter of fact, you can use pretty much any lobe in that solid flat tappet section of the catalog with a Ford lifter. A larger lifter diameter will change the specs ever so slightly, but they are compatible.
The lobes towards the top of the section are the ones you would want for a street car. When you start getting into the XTX and XTQ lobes, then the lobe aggression starts going up considerably, which means that you have to take a new mindset in oiling and spring pressure requirements.
If you stay with an Xtreme Energy, High Torque, High RPM, or Tight Lash lobe, you should be pretty free to do what you want.
To get to your other question, for a duration as short as what you're discussing, i.e. a 236 or 248 @ .050", it's not worth it to go to the aggressive lobes. The rpm just won't be there. In addition to that, the advertised durations on the aggressive lobes are shorter as well, which means that your engine's tolerance to pump gas will not be as high as well.
If you're looking to play around with some different lobes for your 452, there are more reliable and effective ways to do it. At your rpm level, the most gain will be from splitting the durations to match the cylinder head flow, tweaking the LSA, and picking a lobe that will use your head's valve lift the best.....all while keeping an eye on compression ratio requirements.
|This message has been edited by blykins on Jan 9, 2018 3:10 AM|