We’ve got the rotating assembly installed, time to slip in the camshaft. The cam is the heart and soul of the engine, it determines where the engine will make torque and how much. A simple cam change can change a small block from a tame street engine to a nasty fire-breathing race motor. Now let’s slam in a monster cam that’ll never idle right but will make big numbers up top.
NOTE: Camshaft Selection
I called Isky and explained to them what I was trying to do, and this is the cam they recommended. From what I’ve been told it’s pretty aggressive for a 2 barrel/restricted intake/iron head motor, but I really like to VE curve it generates in these engines so we’re going to keep using it.
Camshaft Installation
Tools/Supplies Needed
- Hammer
- Large Socket
- Harmonic Balancer Installation Tool
- Assembly Lube
- Blue Loctite
- Cam Degree Wheel
- Dial Indicator
- Black RTV
- Gasket Sealant
Important Specs
- Cam Bolt Torque: 25 ft*lbs
1) Install Lower Timing Sproket
Tap the woodruff keys into the crank. If they’re being stubborn you can break the edges of the keys with a file. They’re going to take some persuasion, but you should be able to pound them in with a simple ball-peen hammer.
Once the woodruff keys are installed, it’s time to install the lower timing sprocket onto the crank. Pull out your timing set and admire the gorgeous new parts you’re about to install. Also read the directions regarding which key slot to use if your timing set has multiple keyways.
Spin the crank so Piston 1 is at TDC. Slip the lower timing sprocket onto the snout of the crank so the desired timing mark is pointing up. The sprocket will only go on part way because it is a press fit (pound fit?) on the crank. Now use a large socket and hammer to pound the lower sprocket onto the snout of the crank until the sprocket is against the shoulder machined into the crank.
2) Install Camshaft
Break out that nasty camshaft and look at those irresistible DD lumps…
I like to temporarily install the upper timing sprocket onto the cam to give me a handle to hold it with and base to set it on.
Right – Cam with upper timing sprocket install, using it as a base
The cam lobes and bearing journals need to be lubed before inserted into the block. Use the provided High Pressure lube on the cam lobes, Isky sends a container with each new cam. Use your normal assembly lube on the cam journals.
Right – Standard Assembly Lube on the bearing journals.
Using the large sprocket as a handle, carefully slip the cam into the block. Be careful not to nick the bearings with any of the lobes as you slide it in. If using a Dart block, I found it helpful to flip the block upside-down so you reach up through the valley to support the cam.
Once the cam is in the block, pop the big sprocket off the cam so we can install the whole timing set.
Right – Once she’s in pop the big sprocket off. Note the cyl 1 is still at TDC.
3) Install Timing Set
READ THE DIRECTIONS: If you bought a Cloyes Timing Set, they include very detailed instructions on how to install your timing set.
For those of you that threw out the directions: First install the cam thrust bearing on the backside of the large sprocket. Make sure you have the bearing orientated in the right direction, with the backside of the bearing facing the sprocket and the silver side of the bearing facing the block (see pic below).
Make sure Cyl 1 is still at TDC and the timing mark on the lower timing sprocket at 12 o’clock. Install the upper sprocket and timing chain so that the timing marks on the sprocket are pointing toward each other and the offset bushing is set to 0°. Only snug down the 5/16” bolts dry for now, we’ll apply Loctite and torque the cam bolts after verifying cam timing.
Right: Make sure timing marks on the sprockets are aligned during initial installation.
4) Set Cam Timing (“Degree The Cam”)
Setting the cam timing, or “degreeing the cam“, is one of the more intimidating tasks of building an engine, but it is much easier than it seems. Ensuring the valvetrain timing correct is EXTREMELY important to make sure the engine runs correctly and makes good power, but it’s very easy to do. Just take your time and double check your results are you’ll be fine.
Great links that discuss Cam Timing in more detail:
- Cam Smith Cams – How to Degree a Camshaft: Lobe Center Method
- Lunati: How to Degree A Cam
- Better Engine Building: The Easy Way to Degree Your Camshaft
- Isky has a great article on their website: Cam Degreeing. This is packed full of info but can be intimidating to a novice builder.
Install and Zero Degree Wheel and Pointer
Set the degree wheel for TDC. You can do this with either a dial indicator or a piston stop. It’s easier to do it with a piston stop, but I don’t have one, so dial indictor it is.
Proper way to determine TDC w/ Dial Indicator –
- Zero your dial indictor when the piston is at TCD.
- Set your degree wheel and pointer as close to 0° as possible.
- Turn crank so the piston is .050” after TDC. Note the degree wheel reading.
- Turn the crank back the other way so the piston is .050” before TDC. Note this degree wheel reading.
- If both degree wheel reading showed the same number, you have the degree wheel properly set for TDC.
- If the readings were different, adjust the wheel/pointer by half of the different between the two readings. (e.g. If .050” After TDC shows 12° and .050” Before TDC showed 14°, tweak the wheel or pointer by 1° so both ways read 13°)
- Whether you needed to make a tweak or not, always double check your results.
Once TDC/0° is set on the degree wheel, set up dial indicator to measure cyl 1 intake lobe lift. There are many different ways to do this, I didn’t have any pushrods yet so I just stacked 2 lifters in the lifter bore and measured off of that.
Right – No pushrods? No problem. Double stacking lifters in order to measure lobe lift. Start with the intake lobe (this pic shows the cyl 1 exhaust lobe, someone email me and remind me to get a new pic checking the intake side)
There are two different ways to check the cam timing, measure when the valve starts to open and close, or measure the lobe centerline. I prefer to set cam timing based on 0.050” of lift (bottom numbers on the Isky cam card shown below.) There is always a little deviation on how each cam is ground, and I believe when the valve actually starts to open and close is more important than where the center line of the lobe is.
Set Timing with Cyl 1 Intake Lobe
Turn the crank until the lifter is on the base circle, and set the dial indicator to 0. Now turn the crank until the indicator shows .050” lift at the lifter. Note the Open timing and compare to the cam sheet. Keep turning the crank until the indicator shows .050” of lift before the valve closes, note the Close timing and compare this to the cam card.
If your open and close timing measurements don’t match the cam card, slightly loosen the cam bolts and turn the offset bushing in the cam sprocket to make an adjustment. Snug the cam bolts back down and check your adjustment. Always double check your results, cam timing is extremely important. You should aim to get your measured Open and Close timing degrees +/- 1° of what’s on the cam card.
Verify Timing on the Exhaust Lobe
Once you’re satisfied with your intake lobe timing, move your lifters and dial indicator over to the exhaust side and verify the timing there as well. This is just a sanity check, if your exhaust timing numbers aren’t close to the cam card, go back and re-check your intake lobe timing. If one lobe is measuring out correctly but the other is out to lunch, call your cam manufacture and tell them they sent you the wrong cam.
Right: Cam card we’re working with. Top Left shows the Cyl 1 Intake Lobe Centerline. Center in the 0.020” Lift Timing and Bottom is the 0.050 Lift Timing.
5) Torque Cam Bolts
We’ve checked and double checked that our cam is timed correctly, time to lock it down.
Pull out only one of the cam bolts. Apply blue Loctite to the threads and a little bit of ARP Lube under bolt head. Thread the bolt back in and snug it down. Now do the same to each of the other bolts, one at a time.
Torque the bolts down to 20 ft*lbs. Make sure they are new Grade 8 bolts.
Right – Torque bolts down to 20 ft*lbs
5) Install Timing Cover
Read the directions. If you bought a Cloyes 2-Piece timing cover (like you should have), they come with detailed directions that are really good.
Install the front crank seal before installing the timing cover. It’s a press fit, so you just have to hammer it in. Make sure the seal is oriented correctly before installing it.
I found it easiest to set a piece of wood on top of the seal and hammering on that to pound the seal into the cover. Tap the seal in until it is flush with the front face of the cover.
Make sure the cover alignment pins are installed in the block. You can easily tap them in with a hammer.
Right: Supplies for cover install
Install the timing cover on the block. Use gasket sealant on both the block and the cover. Use a small dab of RTV in the corners of the cover.
Please remember to but the actual gasket between the cover and the block. Use 1/4” cap screws to install the cover.
ADD SECTION ON PLATE AND BUTTON INSTALL
6) Install Harmonic Balancer
Go to AutoZone and borrow their Harmonic Balancer Installation Tool (or go buy your own Mr. Money Bags)
I like to put a little assembly lube on the crank seal, crank snout, and balancer. This should help the balancer press on a little easier. Lube on the seal will help protect the seal during the first could start ups.
Slip the balancer onto the crank snout, install the tool, and crank her down til she bottoms out on the timing gear. The face of the balancer will be 3.00” from the front of the block when it’s completely pressed on.
5,6 – Install Tool 7 – Crank her on!
Right = Fin.
WHAT’S NEXT
Rotating assembly is installed, cam is install and timed. Depending on what parts are available, we can move onto;
- Cylinder Head Installation
- Bottom End Clean Up
