mrr23

iTrader: (3)

here's mine. 99 formula back when it had the stock cam. while not 23 exactly. it did produce.

dyno 9 before
dyno 11 500 miles later
dyno 14 10 months later

mrr23

iTrader: (3)

$1100.00?? the rocker kit is $699.00 for rockers, posilocks, chrome-moly pushrods. guideplates, and screw-in-studs. unless you are including a labor charge.

this can go on forever. when most say, it's not WORTH it, they are referencing dollar per horsepower. nothing else. it is worth it when the person doesn't want a cam, but wants more out of what they have.

jus1975

Well I want to know how to adjust the my Comp Cam Pro magnum rollers. And how do you know if they adjusted correctly or incorrectly.

jus1975

Hey Chevy6000VHO,
How hard was it to install that gage cluster with the trans temp. What did you have to do?

jmproductions

If they are an adjustable rocker then the procedure is probably the same as or very similar to the Vinci rocker adjustment technique

2004Sierra

I have the 1.8 HS rockers. I paid i think $411 after tax at summit racing. But with the stock tune u will need a programmer or tune of some sort or u will have cylinder one misfire.

vettenuts

iTrader: (4)

There are advantages to the roller rockerss, and yes I run the Cranes too. I recently installed new Dart heads, and I was considering returning to the stock rockers because the Crane 1.8's I was running were going to push my valve springs to the edge and I wanted to longer spring life for maintenance reasons. When I looked at the wipe pattern as I was setting up the heads on the bench with the stock rockers, I was amazed at how bad it was. Anyone who has had off their rockers, look at the contact pattern on the valve stem end, you will see the pattern is wide and sometimes off the center (side to side). Once I saw this and compared it to the wipe pattern I could achieve with the Crane rockers I had, I went out and bought some Crane 1.7's to replace my 1.8's (but am still holding the 1.8's for future installation). The wipe pattern I could achieve with the Cranes was far superior to the stockers for two reasons. One was the small contact patch of the roller OD on the valve stem, second, with the adjustability of the valve train I was able to place the contact wipe pattern right where I wanted it.

A couple of other notes. If you think you are getting cam lobe lift X rocker ratio at the valve, think again. It comes down to system stiffness. All of the components are offenders to some degree, but the primary culprits are the pushrod followed by the rocker arm. The Cranes are much stiffer than the stock rockers so the deflection (loss of lift) at higher RPM will be less.

If you study the design of the Crane rocker vs. say the Harland or Yella Terra, they you will see that the material added to the rocker did two things, it increased stiffness while keeping the rotary mass inertial components down. The design is sculpted to reduce bending stress concentrations, with a material arch above the fulcrum.

I was also not willing to modify my valve covers, the Cranes fit with no modifications there either. I have seen guys take out baffles to fit aftermarket valve train components and then later post they have oil consumption issues. I also looked at the Jesel's. Very nice components but they were going to require modifying my heads for pushrod clearance and the valve covers, neither of which I wanted to do. Again, a compromise on my part as shaft mounted rockers are more stable than stud mounted.

If you read David Vizards valve train book, he explains the arching of the rocker. There are also over and under arching rocker arms. The worst rocker you can buy is one that starts off at 90* to the valve stem, which is sort what the stock unit is. Maximum valve acceleration is achieved at this point and the stockers start there. You really want maximum valve acceleration when the piston is approximately 78* ATDC. The actual lift on the stock rocker doesn't reach 1.7 until almost full open, it actually starts at a lower lift ratio so what Quiet Tahoe is stating is true, the valve motion diagram will be quite different with the Cranes than with the stockers. This is a compromise on GM's part for simplicity and valve train life. Lets face it, most people want to buy their vehicle and drive it until it rots out (at least up here in New England) without having to maintain the valve train. Most people likely don't even know what a valve spring and rocker is. Once you start modding, the net result is you need to be more concious of the service life as stiffer springs are higher stressed and have shorter fatigue life as a result. This is a reality that you accept when you start modding the engine.

As for selecting a cam, I know someone running an XER Comp cam, Comp 918 springs and Crane 1.8 rockers and he loves the setup and it pulls to a very high RPM on his Z06. Obviously care must be taken in selecting any parts, but it is not one size fits all and I keep reading the same old wives tales over and over, which are basically repeating what has been stated as gospel elsewhere.

Bottom line, they are a lot of money that is true, but they are a quality product that provides good performance. Before you ask, I don't have with and without comparisons of the rockers. I did my installation with other components so it would be hard to extract the rocker arm portion. But then again, hp is not the only reason I put these on and actually a minor one at that. My valve train is also as quiet as stock, even with my new Morel lifters.