Publisher's
note: I was on the website of our friends at COMP
Cams, the leading manufacturer of camshafts
and valvetrain components, and saw this very informative
article that I thought would be helpful to share with
you here.
Flat
Tappet Camshaft Failures (Hydraulic & Solid/Mechanical)
Recent changes in oil and
engine technology are likely the cause of premature
camshaft failure; here’s how you can protect your
engine.
Premature
flat tappet camshaft failure has been on the rise recently
and not just with one brand or type of camshaft. In
almost every case, the hardness or taper of the cam
lobe is suspected, yet most of the time that is not
the problem. This growing trend is due to factors that
are completely unrelated to camshaft manufacture or
quality control. Changes in today’s oil products
and “advancements” in internal engine configurations
have contributed to a harsher environment for the camshaft
and a potential for failure during break-in. But there
are several things you can do to curtail this discouraging
trend.
Engine
Building Tips & Parts Selection
Engines are great at providing oil to every engine component
except one – the camshaft. Windage trays that
limit oil’s ability to reach the cam and lifters,
modification of connecting rod side clearances for less
oil splash and special oil pans further complicate both
the break-in process and camshaft lubrication in general.
Careful and informed selection of your engine components
and lubricants can greatly reduce your chances of having
a failure.
Lifter
Selection
COMP Cams® offers flat tappet lifters (solid/mechanical)
with oiling holes in the cam contact face, which will
increase oil flow to the lifter face to camshaft lobe
contact point. Furthermore, using a lifter grooving
tool (COMP Cams® Part #5003 for GM engines; see
catalog or website for other engine makes) will enhance
oiling throughout the camshaft and valve train. As we
all know by now, better oil flow means better initial
break-in and increased camshaft durability. Additionally,
make sure you purchase only high-quality lifters from
reputable sources. Most lifters look alike, but you
don’t really know where they were produced. “Imported”
flat tappet lifters often times use inferior lifter
castings and DO NOT deliver the durability of COMP Cams®
high-quality, US-built lifters. COMP Cams® lifters
are built to strict tolerances on the diameter and linear
dimensions and designed to fit each application with
the highest level of quality. This ensures the lifter
rotates properly and decreases the potential for failure.
Additionally, COMP Cams® flat tappet lifters have
the correct oil band depth, width, and location to properly
regulate the internal oiling of your engine.
Camshaft
Nitriding
Nitriding is recognized by metallurgists worldwide as
one of the most effective ways to increase the case
hardness and lobe surface lubricity of flat tappet cams,
all in an effort to enhance both break-in and long-term
durability. Pro Plasma™ Nitriding is a patented
process that uses pulsed nitrogen plasma to infuse nitrogen
ions into the part – strengthening and fortifying
the material on a molecular level, through a depth of
approximately 0.010 of an inch. Once again, COMP Cams®
has proven their technological leadership by becoming
the first aftermarket valve train company to own and
operate a Pro Plasma™ Nitriding service in-house.
Available for any COMP Cams® flat tappet camshaft,
this customer-requested service (COMP Cams® Part
#1-111-1) has been proven to deliver unmatched wear
resistance and uniform case hardness. In addition, nitrided
versions of the most popular flat tappet grinds from
COMP Cams® are now on the shelf and available for
quick delivery.
Engine
Oil Selection
Another major factor in the increase of flat tappet
camshaft failure is your favorite brand of engine oil.
Simply put, today’s engine oil is just not the
same as it used to be, thanks to ever tightening environmental
regulations. The EPA has done a great job in reducing
emissions and the effects of some of the ingredients
found in traditional oils; however these changes in
the oil have only made life tougher on your flat tappet
camshaft. The lubricity of the oil and specifically
the reduction of important anti-wear additives such
as zinc and phosphorus, which help break-in and overall
camshaft life, have been drastically reduced. In terms
of oil selection, we recommend oil with the proper level
of “ZDDP”, Zinc Dialkyl Dithiosphosphate
additive fortification. Recent market trends and misinformation
have led to a new and adverse side effect known as “Overloading
on ZDDP”. When overloading on ZDDP, the additive
can actually cause blocking of other important additives,
such as friction modifiers or detergent agents. It is
imperative that the ZDDP level is carefully specified
and blended to correct concentrations.
Engine
Oils, Supplements, & Additives
Making certain that the camshaft and lifters are properly
lubricated upon installation will guarantee that they
are protected during the critical start-up of your newly-built
engine. COMP Cams® offers the right product for
this job (COMP Cams® Part #153), and it is available
in
several different size containers for engine builder
convenience. COMP Cams® also has a line of Break-In
Oils (COMP Cams® Part #1590 [10w30] and #1595 [20w50])
which have a proprietary formula that includes the proper
amount of critical additives, including ZDDP (Zinc &
Phosphorus), Molybdenum, detergents and high grade base
oil to give you the most optimum oil for the break-in
and long-term running of all your purposefully chosen
performance engine components. If you have a preferred
oil with which you feel comfortable, we strongly recommend
the use of COMP Cams® Break-In Oil Additive (COMP
Cams® Part #159) during break-in. While this additive
was originally developed specifically for break-in protection,
subsequent testing has proven the durability benefits
of its long term use. This proprietary blend of anti-wear
ZDDP fortification, anti-fiction Molybdenum, and extreme
pressure additives promotes proper break-in and protects
against premature cam and lifter failure by replacing
some of the beneficial ingredients that the oil companies
have been forced to remove from off-the shelf oil. These
specialized COMP Cams® lubricants are the best “insurance
policy” you can buy, and are the first step to
avoiding durability problems with your new flat tappet
camshaft.
Proper
Camshaft Break-In
Proper flat tappet camshaft set-up and break-in, as
any engine builder knows, are keys to the life of a
camshaft, both short and long term. The correct procedure
allows the lifters to establish rotation and develop
a good wear pattern.
Pre-Installation
Remove the camshaft from the box, and clean it with
mineral spirits or a parts washing solvent, then perform
a visual inspection immediately. Look carefully for
dings, dents, deep scratches, or any other defect that
may be detrimental to the break-in or long-term life
of the camshaft. Pay special attention to the lobe and
journal contact surfaces and distributor gear. Before
installing the camshaft apply an ample amount of the
supplied camshaft and lifter installation lube (COMP
Cams® Part #153) to the lobes, journals, distributor
gear, and lifters.
Break-In
Preparation
Always remove the inner spring during break-in when
using dual valve springs, or if you have a high load
single spring, use a lighter spring. An alternative
solution that addresses this same concern is using a
set of low-ratio break-in rocker arms. Both of these
solutions provide your best chance of proper camshaft
break-in and long term durability. While these tips
may be a slight inconvenience, a little time and effort
on the front-end is much better than destroying your
new engine.
Proper
Procedure
As soon as the engine fires, bring the rpm up to 2000
to 2500 during the first 30 minutes of operation. Slower
engine speeds will not supply the camshaft with an adequate
amount of oil for the break-in period. The engine rpm
may be varied periodically from 2000 to 2500 to direct
oil splash to different areas of the camshaft. After
the 30 minute break-in period, change the oil and filter
again to be sure all contaminants and break-in lube
are removed from the engine. The inner valve springs
should now be replaced and the correct rocker arms installed.