Tech Notes:
 TECH - FAQ's  

PROPER CAM TIMING

  
 
 
Camshaft timing is very critical to the 20R and 22R series motors.  With the early motors, the double row chain was very adequate, however, in late 1983 Toyota started the change over to a single row timing chain with plastic guides.  It became very apparent that the single row chain would have a greater opportunity to stretch and eventually affect the cam shaft timing.

Correct camshaft timing itself is relatively simple to achieve.  Find TDC on the #1 piston, set the cam with the dowel pin in the twelve (12) o’clock position, adjust the tension out of the timing chain with the guides (in most cases, this step is unnecessary with a stock set-up) then complete the rest of the 		 

Set the cam with the dowel pin in the twelve (12) o’clock position.
 
installation as required.  If you have to degree in a camshaft, you will need as adjustable cam gear, a degree wheel, magnetic base dial indicator and a piston stop.  You will then need to follow the instructions supplied with the adjustable cam gear.
 
 
     
  VALVE LASH  
     
 

Rocker Arm Adjustment

  
     
 
   

Both the 20R and 22R series Toyota engines have an overhead camshaft and require rocker arms to activate the valves.  With this type of configuration, rocker arm adjustment is required from time to time.

The best way we have found to adjust the rocker arms is to place each piston, starting with #1, at TDC and use a feeler gauge with a moderate pull, adjust the intake

 Valve lash adjusting location
 
 
valves to .008” and the exhaust as .012”.   If this setting is too noisy they can be set to .007” intake and .011” exhaust.
Aftermarket cams have more of an aggressive profile and some will require different valve lash. Consult your cam card to determine the correct valve lash settings.

Please Note:  When adjusting valve lash. It is recommended that the motor be at operating temperature or at least warm.
 
     
 
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