Question on roller rockers....
03-07-2005, 09:27 AM
#1
Question on roller rockers.... A guy I work with has a 99 Z28, and he bought a set of rockers for it. Mods right now are Granatelli lid, MAC headers/ORY and MAC exhaust. He bought Crane Cams Gold 1.8 rockers, and one of his gearhead friends is telling him he will see better results if he only installs the rockers on the exhaust side. Im saying his friend is wrong and he should install the rockers on both sides. I cant see increasing valve lift on only the exhaust side would provide more performance than increasing lift on both sides. Whos right and whos wrong here? Thanks for any insight you guys can provide.
03-07-2005, 09:40 AM
#2
Using unequal rocker ratios was popular on the old school SBC, but I never did understand why it would be better than just changing all of them. Maybe to save money and put the lift where it is most needed. On an LS1, the intake valves are more sensitive to lift, so if you were only going to do one valve, I would do the intake.
03-07-2005, 09:52 AM
#3
He was trying to tell the dude I work with, DJ, that it cleans up the incoming intake charge because its getting rid of the exhaust gasses faster than the intake can come in. It makes sense, but what I'm thinking is that because the exhaust scavening has been sped up, its going to help pull in more of that intake charge, correct? And because of this, its going to also pull more of that charge out into the exhaust, lessening the amount of air/fuel there is to be burned for power, making the power stroke weaker. Now if you increase the intake lift as well, theres going to be more charge coming in, helping to offset the loss of air/fuel through the exhaust which is being scavenged more efficiently.
Am I correct in my thinking or is that all just a bunch of BS??
Am I correct in my thinking or is that all just a bunch of BS??
04-02-2005, 07:14 PM
#4
You're thinking right, but there's many other variables that come into play. For some setups, this may be the answer, and not for others. The duration and overlap of the cam is going to have the biggest influence, provided the exhaust is free flowing enough to support the cam.