Rocker Arm Shafts
When installing the rocker arms on a shaft type system of a Chrysler engine, the shafts must be installed correctly. There is a difference in the top and the bottom, as well as side to side. The shafts must be installed with the oil holes pointed to the bottom and to the outside of the engine, toward the valve. This is the only way the shafts can adequately oil the rocker arms. Premature wear will result if the shafts are installed improperly.

Lifters
The pushrod seat location is different in hydraulic and solid lifters in most applications. For this reason, pushrod length must be checked and may need to be changed when switching from solid to hydraulic camshafts.

When installing a roller cam and tappets into a Chrysler engine, you must be careful to ensure that the roller lifter sits in the lifter bore correctly. Most brands of roller lifters are designed with a cut-out in the lifter body around the lifter wheel. If this is installed toward the oil galley in the block, the result will be a loss of oil pressure and engine damage. COMP Cams® roller lifters do not incorporate this cut out, so there is no problem when using COMP Cams® lifters. When installing roller lifters in the block, remember to install the link bar side of the lifters to the cylinder side in small blocks and to the inside in big blocks and Hemis.

COMP Cams® produces a special lifter for oval track use in the “A” engines. This lifter is still the standard .904” diameter but is made to oil through the pushrod. This is for use in special highly modified blocks only and will not work in a standard block.

There are several different roller lifters listed for the Hemi engines. The only difference is the location of the pushrod seat.We have basically developed a drop-in replacement for most of the popular brand lifters available. Be sure to measure the height of the pushrod seat prior to ordering lifters.

Lifter Bore/Oiling Modifications
Even though COMP Cams® roller lifters will work without oil system or lifter bore modifications, it is highly recommended that on any racing engine the lifter bores be modified. This will ensure that in the case of a pushrod failure and the lifter coming out of the bore, adequate oil pressure will be maintained. The proper procedure for this modification can be found in any of the materials available directly from Chrysler, or any top engine builder can perform this modification.

Camshaft Journal Diameter
Many of the newer racing engines utilize a larger than standard cam bearing journal diameter. The advantages of the larger diameter are less flex and a larger base circle to smooth out the lobe design, making this a very desirable addition to any extreme racing engine. It is very common to use a 2.125” Ford babbit bearing in the Hemi engine. Some of the latest oval track blocks feature a roller bearing and require a 1.968” journal diameter. Make sure to specify journal size when ordering your cam. If no special size is requested, the standard journal will be chosen.

Camshaft Cores/Timing Chains
On the big block “B” and “RB” engines there are two designs of the cam snout/upper timing sprocket where the cam is attached to the gear. The most common design is the single bolt type, which just means that the cam is attached to the timing chain with a single bolt. There is also the 3-bolt type, more common in high performance applications. These designs are totally inter-changeable, as long as the proper cam is used with the correct timing chain set. In any case, the 3-bolt design is the only style available for roller camshaft applications.

Multi Groove Valves
No longer is it necessary to convert to “Chevrolet” style single groove valves to benefit from the superior strength of COMP Cams® machined steel 10º Super Locks™ and the variety of spring retainers available with this lock. Super Locks™ are now available for the multi groove Chrysler valves in both the 2 and 4 groove applications. They are available in pairs or in a kit with half 2 groove and half 4 groove locks. See page 311 for details.