[Giugiaro]

Originally Posted by RallyBob

The issue with running taller valves is you'll either need to gut the hydraulics and convert to solid followers, or shorten the base circle of the camshafts appreciably. A smaller overall lobe will have greater stresses imparted to it and to the cam followers.

If you are going with much higher lift than stock, then presumably the shape of the lobe is far more aggressive. A more aggressive lobe *may* run into problems with the hydraulic adjusters. There's a lot of mass there for the lobe to toss around, so you may in fact encounter some issues with valve float that you wouldn't see with a stock cam profile. Strictly speculation on my part, but be aware you may be doing a lot of R & D to find out!

after reading your comments here guys and talking to subaru experts who have previous experience with hydros, i realized that an agressive hydro system might work well in the beginning but later on experience problems. needless to comment about the oil pump issue.

i think i'd better go with the solid system.

thanks

E.