Exhaust valve question
Race Director
Joined: Feb 2002
Posts: 11,268
Likes: 14
From: Honolulu, HI
Re: Exhaust valve question (ir0nmaiden420)
What prevents the exhaust valve from opening during compression, and causes it to open after the combustion?
Valve Spring closes Valve. Cam/lifter/rocker opens valve.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Exhaust valve question (ir0nmaiden420)
Indeed the valve springs hold the valves closed unless they are forced open by the rocker arms.
The cam turns at 1/2 the crank speed and the cam lobes are ground so that it (through the valve lifters) pushes up on the push rods, which rotates the rocker arms and opens the valves at the proper time during pistion travel.
This allows one camshaft to control both intake and exhaust valves during two crankshaft rotations, completing the 4-stroke cycle of our SBC engine.
The cam turns at 1/2 the crank speed and the cam lobes are ground so that it (through the valve lifters) pushes up on the push rods, which rotates the rocker arms and opens the valves at the proper time during pistion travel.
This allows one camshaft to control both intake and exhaust valves during two crankshaft rotations, completing the 4-stroke cycle of our SBC engine.
