TECH - FAQ's

 
EFI PRO/STREET PERFORMER CAMSHAFT TIMING SPECIFICATION
 

Application: 1022021 - Camshaft - 20R/22R EFI Pro Camshaft
1022054 - Camshaft - 20R/22R Street Performer Camshaft


This Camshaft must be installed with new rocker arms. LC Engineering, Inc. will not warranty any camshaft that was not purchased together with Aluminum rocker arms. The use of Pro Valve Springs & Retainers or the Pro Camshaft Kit is required with this camshaft.
  Intake Exhaust
Valve Lash .008 .012
Valve Lift .440 .440
THE FOLLOWING FIGURES, TAKEN @ .050 LIFT AT VALVE, WITH .000 VALVE LASH
Duration @ 50 230° 230°
Lobe Center 102° 118°
Lobe Separation 110°  
Intake Opens 13 ° BTDC Exhaust Opens 45 ° BBDC  
intake Closes 37 ° ABDC Exhaust Closes 5 ° ATDC  


NOTE: Always check valve to piston clearance and Valve to valve clearance with this Camshaft! Failure to install this cam with matched valve train components can cause engine damage.

CAMSHAFT BREAK-IN PROCEDURE

The first few minutes on camshaft and rockers is the most important wear period. In this period the cam and rockers become burnished together. When installing the camshaft thoroughly coat the lobes with the special assembly lube provided. Cam should be installed per factory service manual procedures.

Set valves at proper lash dimensions, and then readjust valves after break in period is completed. CHECK valve train for interference. CHECK valve to piston clearance, you must have .100" min. CHECK valve spring retainer to valve guide and seal for clearance. CHECK valve springs for coil binding, you must have .090" min. Of free travel before the springs become solid after the valve in fully open. 98 percent of all cam failure is excessive valve spring pressure.

Start engine quickly, excessive cranking of engine is not good for the camshaft. Bring rpm to 1500-1800 for 20-30 minutes (ABSOLUTELY NO IDLING AND NO REVING OVER 2000 RPM) during the break in period. Camshaft should now be burnished to the rockers. It is absolutely vital that once a cam lobe and rocker have been burnished together, they remain together. So if the camshaft and rockers are removed from the engine, be sure the rockers are numbered and reinstalled on the same lobe. Failure to do this is asking for disaster.

NOTE: LC Pro Valve Springs (P/N 13-108P) Installed height at 1.600 - 1.650

TO CHECK VALVE TO PISTON CLEARANCE WHEN THE ENGINE IS ASSEMBLED:
After installing a new camshaft, lash #1 intake valve to zero then screw intake valve in .060 (Valves not closing completely) turn engine over carefully with spark plugs removed by hand. Do intakes first, if OK then do exhaust. If engine cycles without binding, you are sure that you have minimum clearance. (If binding occurs piston clearance is required). All cam specifications are check at .050" lift. Standard degreeing procedures should be followed for maximum performance.

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