price being the biggest factor on a roller cam, will I see a substantial gain from full 1.6 rr's compared to a better cam? and which cam would be better on an 88 350tpi? I want it to idle fairly well with better power than stock, but not make the car hard to drive?

 

I know 1.6 rockers are only good for a little power at best. People say 5-18hp depending on who you talk to/rollertip vs. full roller...BUT They sure are a lot easier to change than a cam, and horsepower is horsepower.

 

If you're going to do it, do it right... This might be of a little help to you, curtesy of www.badasscars.com

Q: Which is better, a solid, hydraulic or roller lifter cam?

A: This all depends on what you're doing with the engine. There's no substitute for roller cams period. The name of the game is flow.. Heads don't flow if the valves are shut. Roller cams have a lightning fast ramp speed. The valves snap open and slam shut much faster than flat tappet cams which means the valves are open for a longer period of time. While a slower ramped cam, like a solid or hydraulic, is beginning to open the valve, the steep lobes of a roller cam (in retrospect) already have its valve wide open, thus more flow into the cylinder. On the same note, the slower ramped cam needs to start closing the valve, and while it's closing, the roller cam is still wide open and still flowing until the very last second and SNAP! It slams shut. The aggressive profile and ramp (lobe) speed of a roller cam also has its drawbacks. A higher lift and faster ramp speed needs stiffer valve springs. Stiffer valve springs require screw-in studs or you'll rip the stock, pressed-in studs right out of the head. Stiffer springs also increase the load on the push rods, so heavy duty push rods are needed. High lift cams add more movement and friction to the rocker arms, so roller rockers are pretty much a must. Most billet steel roller cams require using an aluminum/bronze distributor gear which is very soft and doesn't last very long (a month maybe?). Just like Newton's law, for every action, there is a reaction, engines are the same way. Increase the load in one place and you'll surely increase the load in other places.

Technology and metallurgy are changing. It use to be that a hydraulic cam wouldn't be very good for a hot street or a mild race engine when in fact, they perform very well! As long as good matching valve springs are used with a good quality set of lifters, there's no reason a hydraulic cam can't do well on the street or the track and if someone tells you different, have them tell that to the guys running hydraulic cams at well over 7500 RPM in 11 and 12 second street cars!


Solid lifter cams are always a good choice for a hot street or race engine. They usually have faster ramps (lobes) than hydraulic cams but not as fast as roller cams. They also usually need a stouter spring than a hydraulic cam but not nearly as stiff as a roller cam. They're kind of the middle of the road between the two. Forget about those lame wives tales about solid lifters always going out of adjustment! That's just not true! The ONLY way the adjustment (lash) can change is if something is either wearing out or going bad, period! If a rocker stud starts pulling out, the lash will increase. If the tip of the valve is getting hammered or mushroomed, the lash will increase. That's what lash caps are made for. If the tip or the cup of the rocker arm starts to wear out, the lash will increase. If a push rod bends or wears out one (or both) of the tips, the lash will increase. If the lifter is getting cupped or the cam is going flat, the lash will increase. If a valve seat "sinks" or recesses, then the valve is actually lifting or sitting higher, the lash will decrease. No matter how you slice it, if a solid lifter cam keeps going out of adjustment, something is seriously wrong! Most of the time it was just a wives tale being spread by someone who's probably never even ran a solid lifter cam or had a piece of junk engine that was falling apart

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1985 Camaro SC - 2.8L, auto.

http://www.xenodrgn.f2s.com/Frontright.jpg

 

Extra ratio rockers are really just a poor mans cam swap. The only time they're really needed is when you can't get enough cam profile to fit in the block. We're talking over .700 lift.

The advantage of going from stamped steel factory rockers to full roller rockers can be 20-30 hp just because they're so much better than the factory rockers. You're getting a more precise rocker ratio and reducing a lot of friction. Going from 1.5 roller rockers to 1.6 roller rockers will usually only net you and extra 5 hp.

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Follow my racing progress on Stephen's racing page
and check out the race car

87 IROC-Z SuperPro ET Bracket Race Car
461 naturally aspirated Big Block

Best ET on a time slip: 11.242 altitude corrected to 10.89
Best MPH on a time slip: 121.52 altitude corrected to 125.89
Altitude corrected rear wheel HP: 497.9
Best 60 foot: 1.546

Racing at 3500 feet elevation with a typical race day over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley