2011 - Crane Cams

CAMSHAFTS
Chrysler Big Block V8 Tech Tips & Notes
1958-1978 350-361-383-400-413-426-440
B & RB V8
The B and RB Big Block Chrysler engines vary primarily due
to cylinder block deck height differences. Intake manifolds,
distributor housings, and pushrod lengths are noticeable
changes from one to the other. The B (Low Block) engines
are 350-361-383-400- (1962) 413, while RB (High Block)
engines are 413-426-400 cu.in. Characterized by inline lifter
bores in the block, inline valves in the cylinder heads, 1.5:1
ratio shaft mounted rocker arms, and a front mounted distributor,
these engines were used throughout Chrysler’s
product lines for over two decades. Be aware that there are
reverse rotation marine, and also gear drive cam industrial
versions of these engines, that require unique camshafts.
Early cylinder heads had removable rocker pedestals for
the rocker shafts, as did the 1960’s performance engines
(Stage II, Stage III, Max Wedge, etc., which also featured
adjustable rocker arms and mechanical lifter camshafts),
while later heads have integral shaft stands.
From 1958 to 1969, all camshafts used a single bolt to
retain the cam sprocket. These have been the Crane 64 prefix
camshafts, with hydraulic and mechanical flat faced lifter
grinds offered. In 1970, the 440 Six Pack engines were
upgraded by having a three bolt configuration camshaft
installed. These are our 68 prefix items, which include
hydraulic, mechanical, retrofit hydraulic roller, and mechanical
roller camshafts and components. The single bolt and
three bolt camshafts can be interchanged among these
engines, providing the appropriate timing set is used. Due
to their superior reliability, we will now be offering only
the 68 prefix three bolt camshafts for their engines.
The Chrysler Hemi 426 camshafts will also physically fit
into the B engines, but due to their different lobe layout,
only four cylinders would function properly.
Our offerings include retrofit 8620 steel billet hydraulic
roller camshafts and steel billet roller lifters to provide an
excellent torque and power band increase. The lifters are a
drop in type (no block machining, or lifter bore sleeving
required), having a vertical locking bar to prevent rotation.
Special pushrods are required due to the increased height
of the lifters.
Our steel billet mechanical roller camshafts are available in
standard firing order (1-8-4-3-6-5-7-2) and SFO (1-8-7-3-6-5-
4-2) firing orders. Roller camshafts for the Chrysler Mega
blocks with 47 degree lifter bank angles, and other aftermarket
blocks having 48 degree lifter bank angles are also
available. Roller camshafts with 2.125” diameter journals
can be custom ordered. Engines equipped with Koffel B1
cylinder heads will require grooving the fourth camshaft
bearing journal for proper upper end lubrication, optional
labor number 98088 accomplishes this. All of our roller lifters
are designed to drop into the block, with no machining
or lifter bore sleeving required.
Early raised cam Chrysler Mega blocks had very tall lifter
bores and a 47 degree lifter bore bank angle, so part number
66554-16 roller lifters (with the pushrod seats and
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guidebars raised .400”) can be used to avoid additional
block machining. Special camshafts are also required for the
change in lifter bank angle, so be certain of what you have
before ordering.
Aftermarket cylinder heads may require different rocker
arms, shafts, pushrods, valve springs, retainers, locks, etc,
than standard. Make sure of exactly what you need before
ordering additional components.
1966-1971 426 Hemi V8
The famed 426 Hemi is related to the RB V8. One primary
change to the cylinder block includes additional head bolt
bosses for the Hemi head’s internal attaching bolts. These
cylinder heads utilize the classic Chrysler double shaft system
for the intake and exhaust rockers. Standard rocker
ratios are 1.57:1 intake, and 1.52:1 exhaust. Lifter bores are
inline, inclined at a 45 degree bank angle. These engines are
indicated by our 66 prefix.
There were also 1964 –1965 426 Hemi 426 engines that
had single bolt camshafts. We recommend using the later
three bolt configuration camshafts and timing sets in these
engines (no other modifications required) for increased reliability.
The Chrysler B/RB camshafts will physically fit into
the Hemi engines, but due to their different lobe layout,
only four cylinders will function properly.
The currently available aftermarket cylinder blocks have
either standard or raised camshaft locations. Most of the
raised camshaft blocks have the lifter bores changed to a 48
degree lifter bank angle, for better pushrod geometry.
Special camshafts are required to maintain proper cam timing
for each side of the engine. Early raised cam Chrysler
Mega blocks had very tall lifter bores and a 50 degree lifter
bore bank angle, so part number 66554-16 roller lifters
(with the pushrod seats and guidebars raised .400”) can be
used to avoid additional block machining. Special camshafts
are also required for this unique change in lifter bank
angle. Some replacement iron blocks may also have tall lifter
bores. Check your lifter guidebar to block clearance
before final engine assembly in the event that modifications
are required.
The aftermarket blocks may also have relocated lifter bore
spacing. While the standard lifter centerline spacing is
1.812”, there are also popular “Spread .100” (1.900”) and
“Spread .200” (2.000”) configurations. Be sure of your spacing
when ordering roller lifters so that you don’t exceed the
travel capabilities of the guidebar.
We offer hydraulic, retrofit hydraulic roller, mechanical, and
mechanical roller camshafts and components for these
engines. When installing our hydraulic roller camshafts and
retrofit lifters, machining will be required on the block and
cylinder heads to provide clearance for the pushrods. This is
due to the increased pushrod seat height on the hydraulic
roller lifters, changing the angle of the pushrods. Our roller
lifters are designed to drop into the block, with no machining
or lifter bore sleeving required.