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Camshaft Installation Instructions
(Updated Mar 2016)
We appreciate your choosing one of our real Chrysler® camshafts and installation kits for your engine. We have
developed the following instructions to help everyone, from the first timer to the experts, install our camshafts
correctly. For many engine builders this may be the most difficult job to do correctly. However for the best tech
help in the industry call (309)745-9558, or email [email protected] When the phone rings a human will
answer. Shop hours 8-5 M-F C.S.T...
Note: We supply coordinated parts such as lifters, springs, Break-In lubes, oils, etc. and we strongly recommend you
use them to make sure you have successful results. Beware, there are many sub-standard parts available that have
high rates of failure, we do not sell them.
The actual cam, lifter, valve spring, and timing chain replacement is fairly straight forward and a standard automotive
service manual procedure can be used….but as you know “the devil is in the details” and that is what we are going to
Intermediate shaft note: ALL Small block & big block flat tappet and hydraulic roller cams can use an O.E.M. style
intermediate gear.
ALL Solid roller cams will require a coated steel distributor gear. Use SB #69970-1, BB #66970-1
There are certain tools you must have to do this job properly and some that make it easier and more accurate.
We will call out the tools and parts numbers where appropriate.
Cleaning and lubrication:
Double check that the number stamped into the end of the cam matches what you ordered. Lightly wash the
camshaft in clean solvent and blow it dry with compressed air. DO NOT BRUSH OR SCRUB A FLAT TAPPET CAM
WITH ANYTHING!! With flat tappet camshafts, apply the supplied camshaft break-in lube to the cam lobes including
fuel pump lobe, and the lifter bottoms only. NOTE: Roller cams do not require break in lube on the cam. Use light
engine oil on the sides of the lifters. Use engine oil or assembly lube on the bearing journals, distributor gear, and
pushrod ends. With roller tappet camshafts use a good quality high zinc engine oil to lubricate the camshaft and
lifters. Oils have changed and not for the better, please use oil specifically designed for your cam type to protect cam,
lifters, and pocket books. THIS IS VERY IMPORTANT!!
Valve springs:
Our camshafts are designed differently and have more lift than other cams of the same size; therefore it is
mandatory that you use a spring with the correct amount of open (over the nose) and closed (seat) pressure and also
check the valve spring installed height. The enclosed camshaft card will tell you our part number for the springs and
the pressures/installed height to use. A minimum of .060” spring travel beyond the maximum lift is required. If you
have a problem, we have many different retainers to adjust the installed height --- CALL US. When checking true
double springs on a tester, be sure to use a retainer or other spacer to simulate the step on the head and/or
retainer for the inner spring to duplicate the as installed configuration. If you are using a double spring assembly
along with a flat tappet cam, we require that you break in the camshaft with the outer springs only*. In this case
assemble the heads with the outer springs only and follow the regular break-in instructions. After break-in add the
inner spring assembly and go racing. Be sure and check the retainer-to-seal clearance. There should be a minimum of
.060” of clearance at maximum valve lift.
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Piston-to-valve clearance:
Chryslers do not have the piston-to-valve clearance problems that many other engines experience. However,
after the valve lifts exceeds .500” and above you must check to be sure. The critical area is not at TDC (top dead
center). The critical areas are approximately 10° to 15° before TDC on the exhaust lobe and 10° to 15° after TDC on
the intake lobe. We suggest a minimum piston-to-valve clearance of .060” intake and .110” exhaust. In the event you
need additional clearance, we have a piston-notching fixture that we rent to our customers. It can be used on a short
block in a car. Call for details. Part number’s Hug 8340 (small block) & 8342 (big block).
Check lifter bores:
The lifters must slide up and down and turn freely in the bore when lubricated only with WD-40 or similar light
oil as a lubricant. You must be able to lift the lifter off of the cam, release it and hear it “thunk” against the cam. If it
doesn’t do this, using only its own weight, it is too tight. If the old lifters had to be forced through the bore to remove
them, it is quite likely that the lifter bore is damaged and will not allow the lifter to rotate properly. It doesn’t take
much to keep them from turning. Fix it or expect problems. Use our Lifter Broaching Tool, P/N 8319, to correct tight
or damaged lifter bores.
Lifters (Tappets):
All flat tappet camshafts (both hydraulic and solid) must be installed with new lifters. NO EXCEPTIONS!!! Only roller
camshafts can be installed with good used roller lifters.
Flat tappet hydraulic & solid lifter clearance & rotation check
It is mandatory that all flat tappet lifters be free in their bores and spin as the cam rotates in the block. We suggest
the following procedure to test for both of these conditions, before final installation of the cam.
1) Install the camshaft clean and dry in the block, with oil only on the bearing journals.
2) Install your new lifters with dry bottoms and only a light coat of WD- 40® or similar light oil on the sides
only. Never use used lifters.
3) Mark the tops of all the lifters and the block with witness marks with a felt tip pen so you can see how far
the lifters rotate.
4) Install the camshaft sprocket, only.
5) Using a speed handle and the proper socket, rotate the cam while applying a small pressure on the socket,
to keep it properly located against the block.
6) Observe the lifters; they must rise and fall by their own weight. If not, they are too tight. We have a
special tool to properly size and clearance the lifter bores, P/N 8319.
7) Rotate the camshaft at the speed of approximately 2 turns per second, for a total of 16 revolutions.
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8) Check the mark on top of the lifter. It must indicate that the lifters were trying to rotate. You would like
to see about 90º rotation indicated, though some may turn as much as 1 full turn. All lifters may not rotate
the same amount or the same direction. If a lifter does not rotate at all - try again – the cam and lifter
must be dry where they contact for this test to work properly. It may be necessary to move lifter(s) to
other bores in order to see rotation.
9) If you encounter a lifter that absolutely will not rotate after following these steps contact us.
10) Make sure to install the lifters in the same bore during final assembly.
DO NOT fill, pump-up, or soak any hydraulic lifters before installation. Mechanical camshafts should be given
slightly less valve lash for break-in only, with iron heads approximately .004”/.005” less. This causes the lifter to spin
more easily. When using aluminum heads the cold lash setting for mechanical cams should be about .006/.004” tighter
than called for hot, during initial start-up and break-in. Be sure and check pre-load or lash when the lifter is on the
heel of the camshaft. If you do not have adjustable rocker arms or pushrods and you find the preload or lash is
incorrect, you may need either rocker shaft shims, longer or adjustable pushrods. Hughes Engines Inc. can supply all
these parts if needed, call us.
Installing and Adjusting Hughes Hydraulic Lifters
1. Do not wash in any solvent. Wipe the parts off with a lint free towel.
2. Use 10W30 high zinc oil and lube the O.D. of the body as well as wheel on roller lifters.
3. The desired lifter-to-bore clearance on cast iron blocks is: .0015” - .0017”.
On aluminum blocks that oil the lifter, the clearance is: .0012” - .0014”.
Both of these measurements are at 70 Deg F.
Aluminum blocks will have a higher rate of expansion and that is why the clearance is tighter.
Adjusting the pre-load setting of the hydraulic lifter
Select the pre-load needed from the list below.
Lifter part numbers 5001, 5003, 5006 & 5007, 5319 & 5321
Cast iron block & cast iron heads: .080-.085”
Cast iron block & aluminum heads: .090-.095”
Alum block & Alum heads:
.100” - .105”
Note: High performance hydraulic cam/lifters are not as quiet as a stock cam. They will sound more like a
mechanical cam.
The instructions on the next page labeled “Valve Adjustment” will give you the procedure to get the intake and
exhaust to be adjusted on the base circle of the cam. Once you get the first pair on the base circle continue by
following these instructions.
1. Place a feeler gauge blade, chosen from the preload setting list above, between the valve tip and the rocker
2. Tighten the adjusting screw, or nut, until you can no longer spin the pushrod by rubbing your finger across it.
You are now at zero “0” lash.
3. Withdraw the feeler gauge and note how far you must continue to turn the adjuster screw to reach zero lash.
Now continue to tighten the adjuster screw that same amount to preload each lifter. Repeat this for each
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Valve adjustment on Mopar V8's
1. Position the piston in the #1 cylinder at TDC on the compression stroke (firing) using the
TDC mark on the damper and the distributor rotor (it should be near the #1 cylinder
terminal on the distributor cap).
2. Read the second column of the chart for the intake valves to adjust and the third column
for the exhaust valve to adjust.
3. Rotate the crankshaft 90 degrees in the clockwise direction (when viewed from the
front of the engine, at the damper). This will bring the #8 piston to TDC. Check the next
line of the chart to find the valves to adjust.
4. Rotate the crankshaft another 90 degrees to adjust the next set of valves.
5. Repeat the process for the remaining cylinders.
Column #1
Column #2
Column #3
Position this
piston at TDC
Adjust the INTAKE
valve on this cylinder
Adjust the EXHAUST
valve on this cylinder
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Magnum (Roller Hydraulic Cams)
Before removing the distributor, mark the base and the intake with “witness” marks so that the distributor can be
reinstalled correctly. Keep in mind that the distributors in Magnum truck applications DO NOT control the spark timing and cannot
be “timed” with timing light. All Magnum hydraulic roller lifters need 2 turns (.080”) of pre-load. Roller cams do not require a breakin or spring changes like flat tappet cams.
Degreeing the camshaft
Why you should degree the camshaft? We want this cam to run the best it can, you should too!!
You’ve spent a lot of money and are going to spend a lot of time—might as well do it right. Degreeing the
camshaft correctly with a dial indicator and degree wheel tells you that all the components that control the position of
the camshaft are accurate. Just because many of the parts are new, does not guarantee they will degree-in accurately
with the other parts, such as the crankshaft. The only way to know is to check. Checking the center-line position of the
camshaft can be confusing due to the similarity of the terms lobe separation angle and center-line. We will try to make
it as easy as possible to center-line the camshaft the correct way.
Note: All Hughes Engines camshafts are ground with some advance in them. This means if the camshaft is degreed-in
to the specs on the cam card it will be advanced to match whatever the cam card says is ground into it.
However, this does not mean if you install the sprockets “dot-to-dot” it will be advanced properly. It should be,
but you don’t know for sure unless you check it. (You do not need to enter the degrees of advance into any of
your calculations. It is already figured in.)
The lobes on Hughes Engines Inc. are non-symmetrical. A non-symmetrical lobe will have a different center-line when
checked at 0.050” above the base circle than it does when checked at the top of the lobe. Hughes Engines Inc.
camshafts must be checked at the bottom of the lobe, which is 0.050” tappet lift off the base circle.
Figure 1
Point “A” is 0.050” off the base circle and is the opening
Point B
Point A
Base Circle
Point “B” is 0.050” off the base circle and is the closing
For example, let’s say our camshaft is advanced 4° and will
have a center-line that is 4° less than the lobe separation
angle. In this case, if the lobe separation angle is 111°, a 4°
advance would be 107° centerline (111°-4°)
“X” is the difference of the center-line at the top of the
lobe vs. at 0.050” off the base circle.
Tools required or that make the job a lot easier
1. Dial indicator with at least .500” travel
2. Degree wheel (Larger diameter is more accurate). The best ones are marked 0º to 90º and then go
backward from 90º to 0º.
3. Pointer for the degree wheel
Note: All of the above are included in kit #8346
4. Crankshaft turning tool p/n 4799 or 67493
5. Height mike p/n 8338 for setting valve spring heights
6. Burnishing Ball p/n 8319
Page 5
Locating Top Dead Center
(Note: Finding true top dead center is the area where many mistakes are made. Follow these instructions
carefully.) In this example we will work with the intake lobe on cylinder #1.
1. Install your “real Chrysler” camshaft, “Pro-Gear” timing chain and gears. For checking purposes only, set the
sprockets “dot-to-dot”. Do not re-use the old chain and sprockets.
2. Start by rotating the crankshaft 360° to position the piston in cylinder #1 back at the top of the cylinder. Then
mount the degree wheel to the front of the crankshaft with the 0 (zero) or TDC mark at the 12 o’clock position.
Mount the pointer to the block and position it to point to the TDC (zero) mark on the degree wheel.
3. Next, mount the dial indicator on the top of the block with the plunger contacting the center of the piston and
about .100” preload.
4. Rotate the crankshaft clockwise and counter-clockwise past TDC. Then zero the dial indicator at the highest point
of the piston travel. This is not true TDC, yet! Again, rotate the crankshaft clockwise until the piston has
descended exactly .060” below TDC as shown on the dial indicator. Mark this position on the degree wheel (masking
tape and a pen works well). Precision is important at this point. Your mark should be approximately 3º to 10º from
TDC. We will call this point “A”.
5. Back up the crankshaft, (turning it counter-clockwise) moving the piston up to the top position and then down in the
bore. Allow the piston to go about .100” down and then stop. Now rotate the crankshaft clockwise until the dial
indicator shows exactly .060” before the piston has reached TDC. At this position, mark the point on the degree
wheel “B”. Exactly ½ way between points “A” and “B” is true TDC.
6. Rotate the crankshaft clockwise until the pointer is at the exact ½ way point between “A” and “B”. This point may
or may not be on the zero mark of the degree wheel, but very close if you have followed these instructions
properly. Now the crank and piston position are at true Top Dead Center. Reposition your pointer to the zero mark
on the degree wheel, and you are ready to proceed.
Checking the Open and Closing Points of the Intake Lobe
1. Install a lifter on the intake lobe corresponding to the piston you just checked TDC (#1). Lubricate the bottom of
the lifter with very light oil, such as WD-40 (do not use cam lube or oil at this time) and check to make sure it
moves freely in its bore. The weight of the lifter and the dial indicator spring are the only things pushing the lifter
down against the camshaft. If the lifter hangs or binds in the lifter bore even slightly during checking, you will get
very confusing results and the job will be difficult.
2. Turn the crankshaft clockwise until the lifter is on the heel (base circle) of the camshaft (See Figure 1). At this
point zero the dial indicator with about .100” preload on the push rod cup in the lifter. The indicator plunger must
be inline with the lifter’s line of travel.
3. Rotate the crankshaft clockwise until the lifter has lifted .050” according to the dial indicator, this will be Point A
in Figure 1. Note the position of pointer on the degree wheel. Masking tape and pen, accuracy important here.
4. Continue to rotate the crankshaft and the lifter will rise to over .300” lift and then begin to descend. When the
lifter descends, equal to what it rose, which will be a point .050” before reaching point “B” the base circle, stop.
Make a note of the location of the pointer on your degree wheel; this is the intake closing point. Always turn the
crankshaft clockwise while checking the camshaft timing, NEVER back up!
Page 6
5. Half way between Point A and Point B is the camshaft centerline and should correspond to the centerline printed
on the camshaft card.
Example 1: When using a small cam where the intake opens after TDC with a 112° lobe separation angle and 3º
advance. If, for example the intake should open at 2° ATC (After Top Center) and close at 36° ABC
(After Bottom Center). Add up the total number of degrees from 2° ATC to BDC (178°) and the
number of degrees from BDC to 36° ABC (36°), 178°+36° = 214°. Divide 214° by 2, this is 107°. The 107°
is added to the opening point of the 2° ATC equaling 109°, which is the proper intake centerline and 3°
advanced for the sample cam.
Example 2: Using a larger camshaft where the intake opens before TDC with a 107° lobe separation angle and 3º
advance. If, for example the intake should open at 21° BTC (Before Top Center) and close at 49° ABC.
Add the 21° BTC and the 180° (from TDC to BDC) and the 49° ABC, which totals 250°. Divide the 250°
by 2, this is 125°. Starting at 21° BTC (the intake opening point) the centerline of the lobe is 125°
after the intake opens which puts the intake centerline at 104° ATC, just as the camshaft card reads.
6. The following are general guidelines for comparing your measured points vs. the numbers on your cam card. If the
centerline is within:
a. 1º of the camshaft spec card, then put then engine together
b. 2º of the camshaft spec card, correct it as necessary.
c. If you have to choose between 1º advanced or 1º retarded, pick 1º advance.
Corrections and Final assembly
Correct the timing as necessary and Recheck. Crankshaft sprockets with 3 keyways, offset keys and offset
bushings are notoriously inaccurate. We have found the Pro Gear® 7 and 9 keyway timing chain assembly to be
very accurate and long-lived, which is why we use and sell them.
2. When it’s correct, clean the threads and then apply Loc-Tite® to the bolts, torque to spec and put it together.
(if the bolt comes loose it will break the dowel pin)
This method is for Hughes Engines’ “real Chrysler Cams” and may not work with other brands of cams.
If the engine is on an engine stand, rotate it so the lifter is vertical which helps it follow the lobe more accurately. In our
shop we use an “extra-long” lifter (7”) to add weight to help the lifter follow the cam lobe and to allow us to position the dial
indicator in a more readable position. The extra-long lifter is 3 old lifters tack welded together.
The process of degreeing a camshaft can require removing and reinstalling the degree wheel several times, re-setting the
degree wheel each time is VERY time consuming. This time can be greatly reduced by using our tool p/n 4799 crankshaft turning
tool. You need to find T.D.C. once on each job. Using cam break-in lube or oil between the cam and lifter during the degree-in
procedure can cause errors, due to hydroplaning.
A common problem encountered when installing a timing chain and sprockets dot-to-dot is to install the ignition distributor
180º out of time. This happens because the piston is on the overlap stroke, not the compression stroke. This is why. When the
sprockets are in the classic installation position, with the cam sprocket’s dot down at 6:00 position and the crank sprocket’s dot up
at the 12:00 and the number 1 piston at top dead center, it is not on the compression stroke. Rotate the crank 1 more turn, putting
both sprockets’ dots at 12:00 and the #1 piston at top dead center. Now you are on the compression stroke, and you can install the
distributor. (No, I don’t know why it is this way. It has been this way forever, on all American engines since timing chains have been
used). It’s probably Al Gores idea; he has lots of good ones! We suggest that you spray the timing chain liberally with gel lube
before installing the timing cover.
Page 7
How to Make the Engine Easier to Start
With the engine on the compression stroke on #1 cylinder, set the crankshaft
to 10º or 12º before TDC as shown above. Install the distributor so the rotor
has just passed the #1 cylinder terminal on the cap as shown above. Make
sure you have fuel in the carb, lines and tank. Fire it up!
Rev softly between 1500-3000 RPM for 30 minutes.
Page 8
It is very important that the engine does not turn over more than 3 or 4 times to fire up. While you are
cranking over the engine, the break-in lube is being wiped off---BAD NEWS!!! Do not crank the engine with a
new cam to:
Bring up the oil pressure.---- Use an oil pump primer shaft
Fill the carburetor with fuel. ---- Use your electric pump or take the line off and fill it by hand
Check the spark. ---- Take the distributor out and spin it by hand with the ignition key on (non—Magnum)
Don’t listen to anyone who says to do this differently, you don’t want a flat cam and we don’t want to hear about a flat cam.
People who tell you differently are not your friends. Triple check the ignition timing see the diagram on page_7_ (approximately 10º
to 12º BTDC is good) and spark plug wire order before touching the key. Most start-up problems occur here. Pump the carburetor
(8 to 10 times) to squirt fuel into the manifold. Make sure your battery is up to full charge and that you have sufficient fuel to run
30 minutes. The carburetor idle screw should be turned approximately ½ to ¾ turn to make sure the engine idles properly. DO NOT
Let the Engine Idle under 2000 RPM the engine for the first 30 minutes. If you have an oil or water leak that is not dangerous
continue to run the engine 10 minutes before you shut it off.
Now you are ready:
Fire it up! The engine should not idle in the first 30 minutes. Rev the engine gently from 1500 to 2500 RPM max. After
the break in period, reset the idle and timing. Check for air leaks (vacuum), fuel leaks, oil leaks, and coolant leaks. Correct as
needed. Install the inner valve springs if they were removed and check the valve lash.
During the break-in period the combustion chambers are very hot and the headers may appear to glow. This is normal and
should go away after break-in when the engine returns to normal idle speeds. Gently revving the engine during break-in will
eliminate or greatly reduce these conditions.
If you do not follow these instructions, you may be very sad!! The most important time in the life of your new camshaft and
lifters are the first few minutes of start-up.
If you have any questions, CALL US BEFORE YOU DO IT! There are no dumb questions. After you make the mistake, they are
dumb questions because you already know the answer. The odds are in your favor, only about 1 in 400 people screw-up and flatten
their cam. If you have any questions about the components recommended for your camshaft refer to the supplied cam spec card or
call us.
Hydraulic lifters that lose their prime (collapse) quickly after start up, have dirt in them. The lifters with dirt in them can be
disassembled and cleaned or replaced. Many problems are created during disassembly of an engine prior to a rebuild by pulling
damaged lifters up through the lifter bore causing grooves and burrs in the bore. These burrs will make lifter spin difficult, if not
impossible. If you flatten a lobe, checking the sides of the lifter with a 10X magnifying glass will show the grooves about 1/8” to ½”
off the bottom of the lifter on the sides. Sometimes they will be deep enough to feel with your fingernail. These grooves act as a
keyway and prevent lifter rotation causing cam and lifter damage.
A dry or improperly lubricated camshaft will suffer damage as soon as the engine is fired up. The lobe and lifter can be
totally destroyed in a few seconds. The engine should run for 16-20 hours before the lobe wear pattern is completely across the tip
and the swirl grind marks on the bottom of the lifter are gone. Quicker developing wear patterns indicate problems such as spring
stack up, wrong oil, or too much break-in pressure. Flooding the crankcase with fuel is a leading cause of cam/lifter failure.
Excessive fuel pressure, sticking float, etc. causes the oil to list its’ lubrication ability. Say “goodbye camshaft.” With Holley type
carbs, we suggest a 3.5 power valve for break-in. Coolant leaks can also destroy the oil’s ability to do its job.
Page 9
Camshaft Lubrication Facts
These oils have either too little zinc-phosphate additive and/or too much detergent to properly
lubricate any flat tappet cam and lifters. They are designed this way due to government regulations
to prevent damage to Algore’s precious catalytic converter. We couldn’t care less about Algore
but we do care about you and your camshaft.
------Details-----Zinc-phosphate (ZDDP) additive is our best friend in oil, especially in break-in oil. ZDDP clings to
hot high friction areas of an engine, specifically cam lobes and lifters. They prevent metal-to-metal
contact with a sacrificial coating on those areas. You need a minimum of 1200 parts per million
(PPM) of ZDDP after the cam is broken-in. During break-in you should use oil with 2200/2400
PPM. This amount is no longer available in A.P.I. rated oils. These are the generally available oils,
and the ZDDP was reduced (by law) to less than 1000 PPM in 1996 and less than 850 PPM in
2001, so you can see how bad it is. Now to make things even worse, detergent, which is also in all
oil in varying amounts, competes with the ZDDP for position on the cam and lifters. The more
detergent, the less effective the ZDDP is. Some oils have sufficient ZDDP but they also have so
much detergent in them as well, that the ZDDP can’t do the job that you think it should, based on
the amount of ZDDP they list. That is why modern oils aren’t suitable for street rod or performance
engines with flat tappet cams*. These facts apply to all diesel and synthetic oils too!
Additives: ZDDP is a family of additives and can react to other oils and additives in non-beneficial
ways when poured in separately. You must be a petroleum chemist to know what will work. You
may think that pouring in a bottle of a ZDDP additive is a cheap way around the problem—it’s not.
All flat tappet cams now require specialty oil. We use and suggest these fine oils.
For Break-In
Joe Gibbs Driven BR 10W30
Joe Gibbs Driven BR 5W30
The above break-In oils are
non-synthetic and suitable
for breaking-in fresh rings.
After Break-In
Joe Gibbs Hot Rod 10W30 Conventional
Joe Gibbs Hot Rod 10W30 Synthetic†
Joe Gibbs XP3 10W30 Synthetic
†We recommend synthetic oil only
after cam and ring break-in.
Page 10
Note: Our soluble-moly Extreme Pressure Lubricant part number 3690 is still a suitable additive
for hydraulic flat tappet cams with 320# lbs open pressure or less and API oils with an API rating
of SJ or SL.
*As an example of detergent-to-ZDDP ratios, API rated oils may have 4 parts detergents to 1 part
ZDDP ratio where Joe Gibbs Driven Break-In is about 1 part detergent to 6 parts ZDDP, over 20
times better!
For further information on oil please refer to our Tech Articles on our website. Engine Oils--Article #203
(309)745-9558 or email [email protected]
Page 11
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