BACKGROUND
MID-LIFT®
THE HISTORY of
traditional rocker arm geometry, for those who've used any philosophy of
design at all, was always based on two things: a SHOE TIP (scuff pad)
contact surface for depressing upon the valve, and a formula for roughly
measuring the rocker arm's length and pivot position which has been
known as the
1/3 RULE. Roller tip rocker arms
were not novel to Over-Head Valve (OHV) engines when they were first
applied to V8 automotive engines in the 1950's, having been used on
radial aircraft engines decades before. But roller tip rocker
arms DID make the
LEAP FROM the SHOE tip principles of design. THIS was
a mistake.
In 1958 the first roller tip
aluminum rocker arms were developed from an inaccurate method of design
that wasted rocker arm motion. (See:
History Of MID-LIFT.) It has been duplicated by every popular
rocker arm manufacturer ever since. It doesn't matter how big the name,
or how long they've been around, even the OEM manufacturers didn't
follow the now accepted (and demanded by some Detroit companies)
geometry called MID-LIFT.
In 1973 a more precise
formula was developed for an engine few people cared about, and the
secret laid dormant for seven (7) years.
In 1980 the secret was revealed
with a FULL PAGE AD in a February issue of
National
Dragster, by its inventor.
In 1982 the only US Patent
ever, for a specific concept of a precision roller tip rocker arm was issued to a
young man who at the time had no intention of building a rocker arm
company. The concept was never used on the popular
engines of racing, but the MID-LIFT Patent prohibited other companies from
adopting it,
so racers were left in the dark. But the concepts were proved across
many years, on arguably the most complex American made engine ever
raced, Ford's BOSS 429 Hemi, from Pro Stock to World Record setting
Alcohol Funny cars.
The
History Of MID-LIFT
explains how an amiable, hard working, easy going Midwest machinist made
a simple mistake by taking an idea in his head to cut and paste
a roller to the end of a shoe tip rocker arm. But how do you explain
the insanity of bad geometry being used by racing's valve train industry
for so many years? The "roots" of most of racing's oldest and most
respected companies lies in men of racing passion, who got their hands
dirty; not in squeaky clean white lab suit engineers sitting at a
draft table holding a slide rule. The answer is underscored by examples
set in Detroit. There is no lack of accredited engineers at Chevrolet,
Chrysler or Ford. Yet, for cost reasons or just adhering to old school
thinking mistakes continued.
MEDIA & POLITICS
Because MID-LIFT was
Patented clear back in 1982, it excluded the claims of big name
companies long ago, so you will find the only thing these "big name"
companies can do is ignore MID-LIFT and dismiss it as "theory." Because they
would look foolish reversing themselves after thirty or forty years of
selling an inefficient "closed valve" design as state-of-the-art. Others,
will speak of it as if they've been doing it right all along. Some even go
so far as to copy MID-LIFT, then say they're not doing it (hoping you won't
notice).
These popular name brand companies spend lots of money on magazine advertising,
and the degree of grossly wrong misinformation even the most well known
companies sell is not only wrong, but insulting; especially when they know
better. (See: Wrong Geometry)
Ad revenues rule magazines; so the whole truth about MID-LIFT and how any
variation that compromises on it, is a subject
that is often “black listed” by many publications to avoid irritating these well advertised companies.
No big surprise. That's business. These companies don't want savvy engine
builders knowing how inefficient their designs are. The result, is even when
magazines finally get around to this tech, MID-LIFT is dismissed as “theory,”
or as only one idea of many being used -- implying there are equally good
options. Not so.
After being enlightened by readers in the know that
it published two grossly inaccurate articles on setting rocker geometry, in 2006 Circle Track magazine
published
"Rocker Arm Geometry and Valvetrain Alignment," which was
reprinted in January of 2009. Presented to Jim Miller as their endeavor to "get
it right," it only makes watered down general references to MID-LIFT geometry
that appeases the less accurate models sold by their big advertisers, while
failing to compare the downside to these less accurate designs, even though the
article was written entirely from information taken from this web site.
Crude hand drawings were copied from the Miller CAD illustrations, then pictures of "name brand" rocker arms that
are not MID-LIFT were added to imply harmony for all, and avoid irritating long
standing advertisers. It is good business for the magazine, but a bogus
implication for the reader, that lends a false sense of generality to how
important precisely designing and setting the geometry really is. In other
words, they're in as much saying: "One was is to do this, and another way is to
do that, and... oh yea... by the way, another way is MID-LIFT."
Here's the facts: There's
only one way, IF, you want the cam's messenger to waste the very least amount of
information while robbing the very least amount of energy in the process.
MID-LIFT! There is "no other way." Period.
Large companies
rely on saturated advertising to remind buyers how big they are, so buyers
conclude their products must be correct. But what you learn here will "vastly"
improve your inefficient over-arcing valve train, that none of these "big
name" companies can challenge. None! No matter who's rockers you use, if you
study both the "Installed Geometry" and "Design Geometry" principles here.
Doing so -- will at the very least -- get you more performance
from whatever brand rocker you're using, while imposing less wear and tear on
your valvetrain.
To
buy exact screen shots and full text from the in depth members section, see:
MID-LIFT TECH.
