ECOTEC rocker arms
01-09-2008, 03:07 PM
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ECOTEC rocker arms **now with pics!! pg. 2**
We're currently in the design phase of rocker arms for the ECOTEC. Seeing as there are no aftermarket units, other than Jessel which are a pretty penny.
The unit body will be made from 6AL-4V, while the roller, needle bearing and shaft will be from carbon steel. The tip of the rockers will not be roller tipped. Rollerizing the tip, from what myself and ray bates found, does not reduce friction for such a small sweep angle and valve tip head. The radiused area actually is better for performance. More info to come as well as a sneak peek pic. The new rockers will be tested against stock units in all areas of fatigue and running in an upcoming motorized jig that simulates rocker operation with oil and heat.
There's been a couple complains of the stock units cracking and even breaking in stock applications. This way people doing builds will have an opportunity to chose a non-stock rocker, and we're confident the price will be much cheaper than the Jessel units.
Thanks,
JBP
The unit body will be made from 6AL-4V, while the roller, needle bearing and shaft will be from carbon steel. The tip of the rockers will not be roller tipped. Rollerizing the tip, from what myself and ray bates found, does not reduce friction for such a small sweep angle and valve tip head. The radiused area actually is better for performance. More info to come as well as a sneak peek pic. The new rockers will be tested against stock units in all areas of fatigue and running in an upcoming motorized jig that simulates rocker operation with oil and heat.
There's been a couple complains of the stock units cracking and even breaking in stock applications. This way people doing builds will have an opportunity to chose a non-stock rocker, and we're confident the price will be much cheaper than the Jessel units.
Thanks,
JBP
Last edited by JBP; 01-14-2008 at 07:38 AM. Reason: updated title
I have no idea what they do...
01-09-2008, 06:24 PM
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rocker arms are like a weight in a way...one end is raised and lowered by the lobes on the camshaft..the other end sits on the valve stem. When the camshaft lobe raises the outside of the arm it presses down on the valve stem opening the valve. When the outside of the arm is lowered by the camshaft it allows the spring to close the giveer
01-09-2008, 06:26 PM
#11
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Rocker arm
From Wikipedia, the free encyclopedia
Generally referred to within the internal combustion engine of automotive, marine, motorcycle and reciprocating aviation engines, the rocker arm is a reciprocating lever that conveys radial information from the cam lobe into linear information at the poppet valve to open it. One end is raised and lowered by the rotating lobes of the camshaft (either directly or via a lifter (tappet) and pushrod, while the other end acts on the valve stem. When the camshaft lobe raises the outside of the arm, the inside presses down on the valve stem, opening the valve. When the outside of the arm is lowered by the camshaft, the inside rises, allowing the valve spring to close the giver.
The effective leverage of the arm (and thus the force it can exert on the valve stem) is determined by the rocker arm ratio, the ratio of the distance from the rocker arm's center of rotation to the tip divided by the distance from the center of rotation to the point acted on by the camshaft or pushrod.
For car engines the rocker arms are generally steel stampings, providing a reasonable balance of strength, weight and economical cost. Because the rocker arms are part of the reciprocating weight of the engine, excessive mass limits the engine's ability to reach high operating speeds.
From Wikipedia, the free encyclopedia
Generally referred to within the internal combustion engine of automotive, marine, motorcycle and reciprocating aviation engines, the rocker arm is a reciprocating lever that conveys radial information from the cam lobe into linear information at the poppet valve to open it. One end is raised and lowered by the rotating lobes of the camshaft (either directly or via a lifter (tappet) and pushrod, while the other end acts on the valve stem. When the camshaft lobe raises the outside of the arm, the inside presses down on the valve stem, opening the valve. When the outside of the arm is lowered by the camshaft, the inside rises, allowing the valve spring to close the giver.
The effective leverage of the arm (and thus the force it can exert on the valve stem) is determined by the rocker arm ratio, the ratio of the distance from the rocker arm's center of rotation to the tip divided by the distance from the center of rotation to the point acted on by the camshaft or pushrod.
For car engines the rocker arms are generally steel stampings, providing a reasonable balance of strength, weight and economical cost. Because the rocker arms are part of the reciprocating weight of the engine, excessive mass limits the engine's ability to reach high operating speeds.
01-09-2008, 06:28 PM
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the rocker arm is the piece that sits on the push rod with a pivot in the middle then to the valve. basically a teater-totter with the pushrod under one end and the valve under the other.
01-09-2008, 06:33 PM
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01-09-2008, 06:41 PM
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New pushrods COMING UP!!! 
Guys, just so we know, the "rocker arm" in these engines is actually a follower. There's big difference between the two. And whats with all this talk about pushrods! See what you started NOS2006. 
So, the lifter end of the follower in this example is the pivot point, versus the fulcrum of a typical rocker arm being actuated by the pushrod.. Thats the big difference between a follower and a rocker arm.
Here's a pic of what Jessels ones look like:
+1 I have no idea what they do...
So, the lifter end of the follower in this example is the pivot point, versus the fulcrum of a typical rocker arm being actuated by the pushrod.. Thats the big difference between a follower and a rocker arm.
Here's a pic of what Jessels ones look like:
01-09-2008, 06:43 PM
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New pushrods COMING UP!!!
Guys, just so we know, the "rocker arm" in these engines is actually a follower. There's big difference between the two. And whats with all this talk about pushrods! See what you started NOS2006.
So, the lifter end of the follower in this example is the pivot point, versus the fulcrum of a typical rocker arm being actuated by the pushrod.. Thats the big difference between a follower and a rocker arm.
Here's a pic of what Jessels ones look like:
Guys, just so we know, the "rocker arm" in these engines is actually a follower. There's big difference between the two. And whats with all this talk about pushrods! See what you started NOS2006.
So, the lifter end of the follower in this example is the pivot point, versus the fulcrum of a typical rocker arm being actuated by the pushrod.. Thats the big difference between a follower and a rocker arm.
Here's a pic of what Jessels ones look like:
01-12-2008, 01:07 PM
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right! same difference.
The design is complete, we have to construct the first prototype and test it rigorously. They should be ready for production after 2 weeks of testing. The prototype will take approximately 1 month to manufacture. So these babies will be hitting the streets if all goes well in 8 weeks.
not bad, my motor build is still a few weeks off, when you think they will be ready for production
