Worn cams = worn rockers

Joe Stewart jstewart@eCompanyStore.com
Wed, 30 Jan 2002 08:58:35 -0600


>Here's what I picture-

Then by your definition, anyone with cams is wasting their time.

The lifter does not know about "lift" or measurements. Here's how the lifter
(HLA) works. When it sees oil pressure, it "pumps up" and takes up any slack
in the valve train. That's it. You can't push a lifter "in" while it sees
oil pressure. After this, the lifter's job is done. The lifter (HLA) doesn't
know lift, timing, anything beyond that, all it knows is "take up the
slack".

Now, let's talk total lift. Cam hits rocker, rocker has slack taken up by
the lifter, and the rocker pushes the valve. The valve doesn't know anything
else but lift. How does it know this? Because the cam pushes the rocker arm.
You have to remember that the lifter is only taking up slack in the system,
and that's it. This amount of slack can change due to cam changes, rocker
changes, etc. The lifter cannot "make up" for lift, it only "makes up" for
slack in the valve train, that's it. So the total lift the valve sees is a
function of the cam AND the rocker, and that's it, the HLA only keeps things
tight.

Regardless of any other explanation, my rockers were visibly worn compared
to new ones. I put them in and the car picked up a substantial amount of
power. That alone proves that worn rockers rob horsepower. When I get a
chance I'll post some pics up of the worn lifters compared to new ones.

-Jay
93.5 G20