In theory (and I am not sure this applies to THESE rockers, but Yella is well known in the high-performance world with mustangs and such) the stamped rokers tend to have some error in measurements (like, a normal 1.5 rocker will ussually be around 1.47 or something like that). While that does not sound like much, when you look at the valve opening, it can translate to some significant power loss, that you would regain with a rocker that has the exact measurements.
Also, you get some ponies freed up from friction reduction, which also lowers the engine's operating temperature. The reduced friction should be specially noticeable for accellaration (in theory). The rocker design should also cause less oil foaming, which also results in better cooling. Theoretically (although I would not recommend it for a Jeep), this means that you could restrict oil flow, and still get the required lubrication, which again (again, this is all theoretical) would release some more ponies.
On the long run, you would also get less wear of the rocker and valve stem, which means that the valve aperture would stay the same (or very close) to the originally set values. Also, because of the rocker, you should get less valve guide wear because the lateral forces that a traditional rocker places as it slides are reduced so much. And last but not least, the rocker itself is much stronger, which should mean less possibility of breaking it (or the possibility to use stiffer valve springs if you chose to go in that direction).
I dont know; they seem to be a good upgrade to me... Granted you, they are not cheap, but I think with all the money I invest inthe Jeep to get more power, it does not seem unreasonable.
I bet you'd get a whole whopping 2HP from these! But yeah its nice for the reduction of wear for a longer period of time but you cant adjust them. I would have to really think about it for a while before I grabbed em.
It would probably be in the 3~4 range I estimate, but considering the HP of the 2.5L in the first place (about 110~120), this is not bad (2~3%). As I said, by itself, not something noticeable, but combined with the 4.0L TB, TB spacer, improved ignition, e-fan, cat-back, etc. the small % keep adding up...
I'd be curious to know if they have done any dyno tests to see how many HP you get for $300
Yeah, I was looking for that on the web, but could not find it... I did find a guy with a strocker that installed these, and he was happy with them and said that the engine ran much smoother and quiet with these on (and a tighter engine ussually means less HP lost in slack). But I would like to find something more scientific... As I said before, though, I would not expect more than 3 o 4 ponies, though.
Anyway, thanks for your opinions!
Felipe