Posted by B.E. (Bradley) Herron on January 31, 1999 at 01:15:41:
In Reply to: Re: roller cams posted by Jim on January 26, 1999 at 15:28:24:
: : are they still around and are they up to the hype of 20 years ago.
: Jim, they sure are still around and in 2 common types: hydraulic roller cams and solid roller cams.
: For pure performance, with a modest amount of extra maintenance and a medium amount of prep machining work,
: the solid roller cams are the ultimate in performance. A roller profile allows you to open and shut your valves with much more
: aggressive profiles, adding mid-range and top end. The hydraulic roller is the best bet for a daily driver in that no adjustment is needed, and they
: tend to be less noisy at startup too. Try "Desktop Dyno", a software package that allows you to try different engine internal combos
: and is pretty realistic. Build a motor and try it with 3 cam types: hydraulic lifters, solid lifters and finally
: roller lifters. Watch the power curve fatten big-time mid and top. The ZZx motors all have hydraulic roller cams.
: Sallee Chevrolet is the best.
: Regards,
: Jim
One thing to remember, though, if your application is using fuel injection, you will want
to use the hydraulic roller cam. The reason for this is the noise generated by the solid
lifters as they slap the cam on open and close is strong enough to fool the computers knock
sensor into thinking the engine is in detonation. The computer then retards the timing
and you never realize the true power potential of the cam. This is why all new cars with
roller cams use hydraulic, along with the minimal maintenance.
B.E. (Bradley) Herron