Originally Posted by Ludachris
Just got off the phone with the folks at Jackson Auto Machine, and we were talking about the valves in the EVO. The fact that they're hollow (lightened) poses an expensive failure waiting to happen. Be sure you change that timing belt religiously. If it breaks, you'll need more than just some head work and new valves like the DSMs do (as the valves would bend). The EVO valves break instead of bend. That obviously doesn't do much good in the engine...
Strange Mitsu would do that.
We recommend that our EVO 8 and EVO 9 customers to upgrade their valves. These factory designed valves are not a good idea to use when doing engine related upgrades, we like to install a full set of stainless steel valves for strength and reliability. The factory valves can cause serious damage if you happen to break a timing belt or even over rev the engine as this can cause the valves to hit the pistons, at which time the valve stems will snap in two - not bend but snap off and then those big metal parts go every place into the chambers, the pistons, the cylinder walls, every where- causing very expensive damage that could have been prevented.