Ok i have a couple of questions about rocker arms. 1. What are the benefits of higher ratio rocker arms like 1.8 vs 1.6.
2. Will 1.8 rocker arms work with a upgraded cam, or a turbo?
3. What kind of horsepower gains will i see with 1.8 rocker arms with lets say... Intake, U-bend Delete, Cat back, reprogrammed PCM.
* on ZZ Performance they say the 1.9 rockers will add 20 hp, i was just wondering how much 1.8 will add.
* oh yeah i realize you need to upgrade springs to precent valve float above 6200 RPM.
4. If i do get 1.8 rocker arms is that safe? for the engine, is the engine gonna last? has anyone had problems caused by higher ratio rocker arms?

I know thats alot of questions, whatever input is helpful tho

higher ratio rocker arms give you the same effect as a higher lift cam, but you dont gain any duration...more simply put, the intake and exhaust valves will open further but not for any longer. This is a mod which can yeild a nice HP gain with out all the teardown reqired to install a new camshaft.

Higher ratio rockers work nicely in concert with other mods like more radical cams...although cam profile choice should be tempered if you are considering a turbo as a future mod. Hi lift, longduration cams do not lend themselves to turbo applications as well as they do to supercharged engines.

Rockers in concert with intake, exhaust and PCM mods will give a substantial performance boost over stock and pose no real danger to your engine at all...our driving habits tend to be far more destructive than the mods we make (burnouts, tire spinning starts or over revving)

To sum up, hi ratio rockers are the next best thing to a better cam, pose no danger to your engine and would add more ponies by themselves but with other mods should yield happy pedal results (along with rice dusting and mustang taunting side benefits)

Hello,

I may be reading this wrong, but..... You don't want to run high ratio rockers with a modified cam. The 2 together don't work.

1. What T-bat said. Valves being more open will allow for easier intake and exhaust. This is a KR fighting mod, since exhaust gas can escape easier.

2. You want to check with the cam maker to see if you can run different rockers with non-stock cams. I don't see a point in doing both because the lobes on the cam essentially can make a higher lift, so whats the point in rockers too? Unless you did rockers first and a cam down the road, and even then you'd want to check around to make sure you wouldn't be screwed.

4. I have not heard of any reliability issues with rockers. SOME have been known to shed metal pieces into the oil, which obviously isn't good for the engine. I read about this on clubgp a while ago.

I would think that to benefit from rockers much, you would need an intake/exhaust and pcm done, as you mentioned. Basically like any other mod, gotta have a few working together, lots of time to support eachother (i.e. smaller s/c pulley would need KR fighting / flow mods to support it).

Somebody correct me if I'm wrong or anything. I just love gp net so much I have to post.

Only reason I didn't outright say not to use aftermarket cams with aftermarket rockers is because zoomer from ZZP once used 1.7 rockers with the VS cam in a nice setup. But crimpton is right. Only the experts can break the rules, I guess.

Unless you have a cam that is ground for 1.9s and 1.8 rockers do not mix a high perf cam and higher ratio rockers. There just isn't enough room in the combustion chamber to operate both. Most of your aftermarket cams have a higher lift and longer duration ground into them negating the need for high ratio rockers. The pros can do it because they know all the numbers they need to ensure nothing smacks into something it shouldn't.

There are some advatages to running full roller rockers with a cam ,I'm running a GT1 cam and 1.7 rr ,but you must have correct length pushrods so that you do'nt have too much lifter preset ,but it would be better to get the cam you want and use 1.6 rr .Chico.

I know I had heard of both aftermarket cams and higher ratio rockers being used on small block chevy engines. But as was pointed out, this was done by pros at a machine shop, taking great care to make sure valve to piston contact didnt take place...both drag and round track racers are always looking to squeeze as much from their engines as possible. I'm sure you've all seen pop-up pistons with valve cutouts and flat-top high comp pistons with "eyebrows" to allow for valve clearance...the two can be used together but the set-up had better be right. Of course once you get that radical, you probably arent talking about a very streetable engine anymore.
Thanx for keeping me on my toes guys

SBCs are quite abit different in head design and clearance issues then the 3.8L. Plus the SBCs have quite abit more available from domed to dished to recessed etc.