First the stupid question: When people say mechanical cam/lifters is that the same as solid I think? Can someone school me on the pros and cons of each of these two? I'm looking at getting a crower cam for my hybrid build and for some reason, they offer a solid cam @ performance level 5, but not a hydraulic, just wondering if there's any particular reason for that, and whether or not I should go with the solid one they offer or get a custom ground hydraulic. Hydraulic specs: HI-DRAULIC HAULER / Performance Level 4 - Strong mid-range and top end torque and horsepower. RPM Power Range: 2200 to 6200 / Redline: 6500 vs. COMPU-PRO / Performance Level 5 - Fantastic top end profile with plenty of horsepower. RPM Power Range: 3000 to 7000 / Redline: 8000 plus. Basically I want the power band and rpm limit of the perf lvl 5, but need to know whether or not there's a mechanical limitation as the reason for them not offering that level of performance in a hydraulic version.

Comp cams makes a Hyd roller with that RPM power band. http://www.compcams.com/Cam_Specs/Ca...?csid=177&sb=2

I believe that the reason the hydraulic cams are generally listed with a lower red line is because of the limitations of the lifters. At higher speeds, I believe, the lifters tend to compress more and then you could possibly end up with problems in the valve train, whereas the solid lifters don't have this problem. However, you will need to adjust the mechanical cam periodically to maintain the proper valve lash. And yes, mechanical cams are solid lifter cams.

That link is to a cam for a v8 and with a lower RPM band at that...
And yeah, Did some research, I guess its because mechanical lifters can just simply go up and down faster, something about hydraulic lifters pumping up with oil or something, while the mechanical ones just have a spring in them? But what I don't understand is why does mechanical require the rocker arms be above the valves, and require lash adjustment every so often? And I don't suppose you have any idea how often that would need done?

I don't think that solid lifters have a spring in them. If they did, they would pretty much be useless, because it's the oil behind the piston counter acting the spring in a hydraulic lifter that makes it work. The reason you have to adjust the valves is because the piston that the pushrod sits in in the hydraulic lifter compensates for wear in the valve train by moving the pushrod out on its own (which is why you have to tighten down the rocker some more AFTER the valve lash has been removed). With the solid lifter, there is no way for the lifter to compensate for wear, to the valve lash has to be readjusted.

I think that older vehicles required valve lash adjustments about every 30K, but I'll have to look it up in my dinosaur car book. It may also be specified in the cam data sheet.

As easy to forgot as it is, alot of our cars are antiques now..

Yes, but at least they have electronic fuel injection and hydraulic camshafts. This book I am referring to still has companies the likes of Datsun (absorbed by Nissan back in the 80s) and AMC (absorbed and later sold by GM to Chrysler, also in the 80s). Not to mention it also tells how to fix BREAKER POINTS and OIL distributors.

:edit: Also, I hope you're planning on making the hybrid a full-out racer, because I think anything beyond a Perf Lvl 2 is illegal, especially in Indiana, where the smog police roam.