Tech Area

Relashing Valves

Question: I installed a Firebird 1995 3.4 liter in my Fiero - direct replacement with few hick ups. I need to relash the valves and need a simple way to do do so. The Fiero book is very brief.

Question 1: Intake valves and exhaust valves - how do I tell which is which, etc.

Question 2: I work for GM and the line workers say don't tighten 1 1/4 times after it is finger tight. They say it's too much - a full turn is enough.

Question 3: Should I follow the Firebird manual for lashing or is the Fiero one good enough.

Question 4: Exhaust open, intake closed - what stroke am I on? I need a little support if possible.

Answer: 1. Exhaust valves line up with the ports to the exhaust manifold. Intake is the other valve that lines up with port coming in from the intake.

2. Workers are correct. 3/4 to 1 turn or a "rule of thumb" is 4 threads showing above each adjusting nut.

3. Sounds like neither!

4. That cyl is on the exhaust stroke. Compression stoke occurs just after the intake valve closes and timing mark comes up. That will be Top Dead Center if you are looking at #1 cylinder. Drop the distributor in with the rotor pointing at #1 plug wire.

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