Inspection guide – Zipper's Performance Red Shift Cams TC User Manual
1.) Crankshaft Run-out
– The first thing to check is the run out of the crankshaft pinion shaft. Gear Drive cams cannot be used
with more than 0.003” of run out on the pinion shaft. If the crankshaft run-out is deemed excessive, further disassembly and
repairs will be required. It is highly recommended that anytime the camshaft cover is removed, crankshaft run-out is checked.
2.) Oil Pump -
Disassemble the oil pump, and draw a line across the inner / outer gerotors with a permanent marker, so they can
be reinstalled exactly as they were removed. Inspect the gerotors and pump body for damage due to foreign material being
pumped through the system. Follow the factory Service Manual for gerotor tip clearances and the overall stack height tolerance.
Replace or repair as needed. If excessive material has gone through the scavenge side of your pump, the oil tank and oil lines
must be cleaned out now as well. Certain models will require the oil pan to be removed for cleaning, while other models require
the entire oil tank to be flushed out with kerosene.
3.) Cam Chain Tensioners -
While apart, it’s a good time to evaluate the operation of your cam chain tensioners. Look for uneven
wear patterns in the shoe especially. Replace or repair as needed. Red Shift Dual Piston Cam Chain Tensioners are highly
recommended on ‘07-Up engines.
4.) Cam Chains -
Check the outside of both the inner and outer cam chains for any burrs or inconsistencies. Some wear may be
present, but any physical damage to the chain will transfer directly into replacement cam chain tensioners.
5.) Cam Support Plate – Oil Pressure Relief Valve -
We strongly recommend
using the Fueling Cam Support Plate Pressure Tool to check the cam support
plate for leaks at the Oil Pressure Relief Valve. This is an extremely critical step
that is completely bypassed in the standard circle of service technician
training. Our testing of hundreds of O.E. cam support plates have resulted in the
discovery of a complete failure of the proper operation of the bypass valve on a
large percentage of cam support plates.
This Oil Pressure Relief bypass valve has been found in many cases to be
leaking 50% or more pressure at idle. These leaks cause a dramatic reduction in
the amount of lubrication on all of the key parts of the engine, especially high
contact pressure valve train parts. Another key issue is in maintaining oil
pressure when the engine is at its lowest rpm, which is hot idle. A precision
ground Oil Pressure Relief Valve may be required to properly seal this bypass
valve. Any losses at this point will systematically reduce oil pressure to the entire
engine, specifically shortening the normal lifespan of the high pressure
components in the valve train and other key areas of the engine. Call your
Zipper’s Sale Rep for more information on this issue and the various solutions
available for you.
6.) Take-Out Camshafts -
Although these are the key items being replaced, it’s the right time to take a moment to inspect the
wear on the lobes and bearing journals. Finding issues on the parts that are being removed will aide you in setting up your new
Red Shift Cams for a long reliable lifespan.
7.) Lifters -
Inspect the lifters’ roller surfaces, the bearing condition, and the outer diameter of the lifter bodies. We recommend
that higher quality lifters be installed when upgrading your camshafts, but studying the condition of the take-out parts will help
you identify previous oiling and control issues. The latest factory lifters referred to as “-99C” should be removed regardless of
mileage, and replaced with a higher quality aftermarket replacement. The newest lifters do not appear to be made to the same
quality standards as the earlier lifters.
8.) Pushrods -
Check the pushrods for unusual wear on the tips, blockage through the body, and any rubbing or interference
marks from hitting the pushrods tubes. You may be reusing these non-adjustable pushrods, if you’ve purchased a Red Shift Cam
that was designed for use with these pushrods. In many cases these will be replaced with a high quality adjustable pushrod.
Many options are available; please call your Zipper’s Sales rep for a rundown on available pushrods for your application.
9.) Rocker Arm Assemblies -
Checking the Rocker Arm Assemblies is commonly overlooked during a cam installation. The rocker
arms are inexpensive to replace, and typically one of the first items to show accelerated wear when operating in a low oil
pressure environment. Do a complete inspection on the rocker arms & assemblies before performing repair work to any of the
parts. You may find that it’s cheaper to purchase a new factory rocker arm than repairing multiple issues. If both bushings need
replacement, the repair cost will be near the replacement cost. A worksheet is provided at the end of this section to aide in the