INSTALLING AND DEGREEING YOUR NEW CAMSHAFT
Before You Start:
INT. DUR. @ .050 SEAT PRESSURE OPEN PRESSURE ---------------- ------------- ------------- 180 to 200 90 to 100 225 to 250 200 to 220 100 to 110 250 to 275 220 to 240 110 to 120 275 to 300 240 to 260 120 to 130 300 to 325
Never Exceed 375 Pounds Pressure.
If you are replacing a failed camshaft, determine why it failed before installing a new one. There may be a cause of failure that will present the same problem for a new cam.
After removing the old camshaft from your engine, thoroughly clean the engine, removing all dirty oil and impurities. Even the slightest amount of impurities can ruin a new cam.
Installing Your Cam:
Prior to installing the new camshaft, inspect the cam lobes, oil holes and bearing journal surfaces for any damage which may have occured in shipping. Use a mild solvent to remove any metal shavings, corrosion etc. Do not scrub or use any type of abrasive cleaning agent. Dry the camshaft with a lint- free towel or compressed air.
Attach the cam sprocket (or 3 to 4 inch long bolts) to serve as a handle when installing the new cam. Lubricate your camshaft with the special prelube provided. Gently insert the camshaft into the engine block with a rotating motion, being carefull not to dislodge or damage the cam bearings (Note: The cam bearings are easily damaged if the side of the cam journal is scraped across the edge of the cam bearing). Once the camshaft is in place, make sure it rotates freely.
Rhoads variable lifters are the only type of lifter that need to be filled with oil before installation. To fill
Rhoads lifters with oil, completely submerge each lifter upright into a container of oil and compress
the innerplunger with a pushrod until it hits bottom. Hold several seconds and release slowly. Repeat
several times until the lifter is completely filled. Soaking the lifters alone will not fill them.
Coat the lifters with camshaft prelube, especially on the bottoms, and place them into the bores. Rotate the camshaft to make sure the lifters move up and down freely.
Install the timing set. Install the valve train for #1 cylinder, adjust and Check for interference at maximum lift:
If any of these clearances is questionable, fix it.
'Good enough' probably isn't.
Degreeing Your Cam:
Mount a degree wheel to the crankshaft and a pointer to the engne block. Remove the rocker arm and pushrod from #1 cylinder. Install a TDC stop in the spark plug hole of #1 cylinder. To locate top dead center, rotate the engine until the piston contacts the TDC stop. Mark the degree wheel at the pointer. Now rotate the engine in the opposite direction until the piston stops. Make another mark on the degree wheel at the pointer. If the degree wheel is properly located, there will be an equal number of degrees on both sides of TDC on the degree wheel. If an unequal number of degrees exists, the degree wheel will have to be relocated. For example, if you come up with 34 degrees on one side and 30 degrees on the other side, the wheel will have to be moved 2 degrees to correct the misalignment. Once the degree wheel is aligned, remove the marks that you made and remove the TDC stop.
Position a dial indicator securely above the intake lifter. The stem from the indicator should be aligned with the lifter as close as possible. Rotate the engine at least two revolutions. Make sure that the dial indicator is working freely and the lifter is not sticking in the bore.
Rotate the engine clockwise until maximum lift is reached. Zero the dial indicator and continue
rotation until a -.050 reading is reached. Mark the degree wheel at this point. Rotate the engine
counter-clockwise until maximum lift is reached again. Continue counter-clockwise until a reading
Installing The Rest Of The Valve Train And Adjusting:
With the piston at top dead center of the compression stroke, hold the pushrod with the thumb and index finger of one hand and tighten the rocker nut with the other while moving the pushrod up and down. The lash is adjusted to zero when you can no longer move the pushrod up and down.
Avoid prolnged cranking of the engine on initial start-up. Once your engine has been started, keep the engine speed between 1800 rpm and 2000 rpm for about 20 minutes. Do not allow the engine speed to drop below 1200 RPM. This high rpm break-in is critical, as low rpms put more load on the cam lobes and reduce valve lifter rotation. With the valve covers off you will be able to see if the pushrods are rotating. Pushrods not rotating indicate that the lifters are not rotating. If this occures, STOP THE ENGINE IMMEDIATELY and determine the cause. Do not restart the engine untill the cause is corrected. When the lifters are not rotating, the cam lobes and lifters will self-destruct, sometimes in a matter of seconds, or create damage that will greatly reduce the life of the camshaft.
If your engine is running quietly after the first 20 minutes,
You have correctly installed your new camshaft.
After the engine has been run-in, you should check and adjust the lash or preload to the proper hot
Last updated August 2012.
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The Accelerated Motion name and logo is a registered trademark of Doug Friesen. All other marks, names and part numbers are the property of their respective owners and are used for the sole purpose of promoting sales and proper use of their products. The information contained at this site is accurate to the best of my abilities and is subject to change without notice.