Keith Craft 482 8 Stack EFI Engine Build

[blykins]

You have to weigh the pros and cons of each one.

A solid roller will allow for a more aggressive lobe profiles and higher spring pressures. Makes it a little easier to hit the higher rpms without much thought involved. Almost anyone can slap in a solid roller cam, lifters, set the springs up, and turn big rpms.

A hydraulic roller will be less tolerant of higher spring pressures just because the spring pressure will start compressing the lifter plunger. There are ways around that and you have to remember that the spring pressure needed will be dependent on the weight of the valvetrain. You can make a hydraulic roller turn 8000 rpm if that's what you want to do. NHRA stock and super stock 5.0 Mustangs do just that, and they do it reliably. An FE will require a little more brain power as the valves are usually longer and heavier, valvetrain is heavier, etc., but it can be done.

With all that being said, you're TONS more likely to lunch a solid roller than you are a hydraulic roller. Since there is lash involved in a solid roller, you have constant pounding of the bearings in the lifter. There are $$$ lifters out there with bushings instead of needle bearings, and are offered to last 25-30k miles. I've got quite a few sets out there in engines, but with the time it takes a Cobra owner to put 30000 miles on an engine, I may not ever find out if they will last or not...