I've been reading in my current Hot Rod magazine about a 383 combo build and I noticed a general statement about hydraulic roller cams/lifters being able to produce/allow more HP than a flat tappet combo. Can it also reduce the possibilty of eating a cam during break-in ? I am building a 454 high perf combo for street/strip and wanted to get some facts about benefits or downfalls of the htdraulic roller combo. I will spend the extra cash if it appears warranted.Thanks for furthering my education.... ;)

Here's the nice thing about a roller cam: there is no break-in. Start it up and drive it.

Originally posted by Texas70:
Can it also reduce the possibilty of eating a cam during break-in ? John,
This is the only part I feel qualified enough to answer. Most certainly! That being because there is no "traditional"break in on a roller cam like a flat tappet! graemlins/thumbsup.gif

Imho, the roller hassle and cost isn't worth it so I go solid lifter cams.. BUT not big, hairy ones that have break-in problems unless you single spring them or use 1.3 ratio rockers or whatever less ratio ones they are??

It always amazes me what a good old CC 282S solid cam does for a decent street motor with respect to power production over stock....

What hassle is that? When I installed my hydraulic roller there was one extra step, setting the end play.

The cost is a one time deal. I can change the cam and keep the lifters so a new roller cam costs me about the same as a quality flat tappet + lifters.

If you are trying to be real competitive, hydro rollers arent the best in an all out situation. But, if you keep it moderate, they can be a great addition to a hot street engine. Try to build it to run 6000rpm or less. Hyrdro rollers dont naturally like to rev as well as a mechanical cam of some sorts. Its basically due to the lifter weight and many of the hydro rollers lifter design. And depending on the layout of your valvetrain, it isnt out of the ordinary to have some troubles running a hydro roller much over 6000rpm witout valve float issues. But, especially in a 454, you have the advantage of being able to build it to run a mild rpm(like 5800rpm or so), and as long as the rest of the motor and drivetrain can keep up to the cam, you can still be very fast at that moderate rpm. If you wanted to run a fair bit over 6000rpm, and you want it to be a roller, Id go with a solid cam(my own preference). For what it would cost to put together an adequate vavetrain for a big hydro roller bumpstick to run real high(not to mention the cam and lifters themselves), its definitely worth considering a solid roller. There isnt a huge difference in cost in either setup, but with the mechanical cam youve got the makings for a stronger revving setup. The downsides are having to set valve lash from time to time....unless you dont mind setting lash. And the valvetrain wear is accelerated compared to a hydro cam, but that still isnt always a huge deal(depends on how radical the cam is and how hard you run it).

Now I wouldnt be surpised if some guys might jump on this saying that they use hydro roller cams and run well over 6000rpm. If thats the case, so be it. Its possible to do if you take the effort to make it work, so dont think Im telling you that you just cant do it. Im just giving you my own opinion of what I would do if I wanted the combination of high rpms with a roller valvetrain(for me it would be mechanical). Just make sure if you plan on excessive rpm's with a hydro roller, dont skimp on the rest of the vavletrain or you might not get the best results.

If you can wait until about April, I will be posting the before and after results of flat tappet hyd to hyd roller cam swap. Plan is to run the car with the exact same setup (same street tires and all) except for the roller and of course the rejetted carb. Dropping out the horrific 60' times of 2.20 and 2.06, the indicator will be the gain in MPH over the base MPH of 99.7 and 97.9 in back to back runs from last August.

Time will tell.

For applications under 6500 rpm and @.050 durations under 245 I would only use a hydraulic roller camshaft, especially in a BBC engine where camshaft break-in can be so critical for a flat tappet camshaft. For a street engine a hydraulic roller can use more aggresive opening ramps resulting in more area under the lift versus timing curve than can achieved safely with a flat tappet. At a given vacuum level (idle and low speed drivability) determined by the amount of duration off the valve seat, the hydraulic roller will provide more airflow and power. Add 5-8 hp at the crank for reduced friction and there is no way a flat tappet can compete. Is there an engine in production today that uses a flat tappet camshaft?

Originally posted by GRN69CHV:
If you can wait until about April, I will be posting the before and after results of flat tappet hyd to hyd roller cam swap.
Time will tell. I look forward to the results, thanks everyone