Aluminum Roller Rockers questions
Basically the single springs used on the eddy's are rated for hyd. lift cams up to .600 lift. And in my opinion even that is questionable. The spring rates associated with solid roller cams will need a spring change. And for a mild street roller there are some double springs out there that will handle the job.
I plan to go hydraulic, whether it's flat tappet or roller.
I also PM'ed tubtar, since he's the one who originally posted the concern for high spring #'s. His response, with permission, for FABO reference:
Originally Posted by tubtar
"I think you are at the outer limits of their performance capabilities at those spring levels.... they might hold up but any more than that would be a problem just waiting to happen. The problems seem to pop up with galling on the shafts because the aluminum is so soft. A bronze bushing will help , but the best answer is a full needle bearing roller rocker. If you do use them , at a minimum , a hardened , banana grooved shaft. Oiling is your friend here. If the rockers need any kind of modification for spring clearance , I would not even use them. Too many compromises are a huge red flag for me. One issue , then maybe. Any more than that and I need to reassess what I am doing."
We agreed hydraulic only, and his suggestion was mild to medium wild roller cam (should I go roller) at most.
My thinking is that I will have to see what spring open pressures would result from the cam I choose. (And what cam to choose? I'm currently going to some experts to see what they think, but of course they are busy so it takes time.) After I know spring pressures, I can see if I can live with roller cam or not. Then I can start hunting down deals on a set of Eddy RPMs, either 60779 (hyd FT) or 60775 (hyd roller). I'm thinking for my needs that one of the two should fit the bill OOTB. (With perhaps some mild porting down the road. ;-)) If it does require nothing more than a spring change, I guess I might do that but then we are back to the starting point of this thread...what can the Speed-Pro (aka Dove) roller rockers handle?
May be a crazy way to process through the build, but it's something. Basically I'm not dead set on roller cam, but it's a nice bonus if I can make it work and worth the effort to research it.
