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what are rocker arms??

2K views 8 replies 6 participants last post by  Slipangle 
#1 ·
* sorry for the newbie Q

what are they, what do they do, and do i need them. I have seen pics but thats about it i am completley lost.
 
#2 ·
rocker arms

from the cam you have the lifter that sits on the cam and when the lifter goes up the pushrod that sits ontop of that goes up to the rocker arm wich changes the direction of the force onto the valve, and also increases the amount of lift as the ratio of a rocker on a small block will increase the lift amount by 1.5.
jesse
 
#4 · (Edited)
Alright, let's make this easier for you:

Your car has a crankshaft. The piston keeps the crankshaft going in a rotary motion. The crankshaft keeps the camshaft in rotary motion. The camshaft has a little offset knuckles on it. Each time that knuckle passes by the pushrod it pushes it up. The pushrod is connected to the rocker arm. When the pushrod goes up it pushes one end of the rocker arm up. The other end of the rockerarm will go down pushing onto the valve. The valve will open.
Look at the atached graph and try to make sense of it. The dark green square is the rocker arm. The black dot in the middle is it's pivoting point. So when the pushrod goes up it pushes one end of the rocker arm up, and because of the pivot point, the other end goes down.
Your car already has these so you do not need to get them unless you want new ones.
The valve the rocker arm pushes down lets in air/fuel mixture or lets out the remaining exhaust fumes. How many rocker arms you have depends on how many valves you have. You probably have 2 valves per cylinder.
I hope this helps,

Mike
 

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#6 ·
Nightfire I think you probably inadvertently confused him even more.

Ok your cam shaft has 16 lobes. Each lobe touches it's own lifter. The lifter moves up. As does the push rod that sits on top of the lifter. The push rod pushes the rocker arm, which opens the valve inside the motors head.

http://images.google.com/imgres?img...?q=engine+diagram&hl=en&lr=&ie=UTF-8&oe=UTF-8

this image moves partially (it's a look inside your motor). I real life the movement starts at the bottom right. That cylinder shaped thing is the lifter, the long thing is the push rod, the piece at the top is the rocker arm and next is the valve spring, valve, and finally the piston.
 
#9 ·
calimstng66 said:
would you recomend getting it
Based on your other post, I assume you are referring to getting new rocker arms to go with all your other Edelbrock goodies?

You're probably fine with the stock rocker arms, just stick with what you have for now. You probably want to become a little more experienced and knowledgeable before you really need new rocker arms.. That's something you really only need when you're worried about reducing the inertia of the valvetrain so you can increase your redline, and there's a LOT more involved in that. (Plus another order of magnitude of cost, look up titanium valves..)
 
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