Adjustment of mechanical lifter valve lash on 216/235/261 Chevrolet truck engines
1. Make sure rocker arm surface is smooth. Grind smooth, if necessary.
2. Warm up engine to stable temperature and then run the engine for 30 minutes.
3. Stop the engine.
Notes:
- exhaust valves are on the ends of the head (look at the intake and exhaust manifold)
- use a flat feeler gauge
- the settings below are in inches
- the settings below might be different for different years' engines
- the settings and instructions are for standard 216/235/261 cams and rocker-arm assemblies
216 cubic inch
Intake: .006 to 008; .010 for heavy duty operation
Exhaust: .013 to .015; .010 for heavy duty operation
235 cubic inch
Intake: .006
Exhaust: .016 or .018
261 cubic inch
Intake: .006
Exhaust: .018 (up to 1 ton trucks); .020 for 1 ton and larger trucks
4. Set the motor to fire on #1 cylinder (the following valves should be fully closed).
Set the lash on:
1 Exhaust
1 Intake
2 Intake
3 Exhaust
4 Intake
5 Exhaust
5. Then, rotate the crankshaft one full revolution.
#6 cylinder should be in firing position (the following valves should be fully closed).
Set lash on:
6 Exhaust
6 Intake
5 Intake
4 Exhaust
3 Intake
2 Exhaust
Tim Lederman (
[email protected])
26 May 2001 (last revised on 31 December 2002)
Also, check out the following Tech Tips:
http://www.stovebolt.com/techtips/valveadjustment.htm http://www.stovebolt.com/faq.html#valves Good luck,
Tim
