How does it affect valve capabilities; timing etc.
2007-02-27 14:22:13 · 4 answers · asked by loren w 2 in Cars & Transportation ➔ Maintenance & Repairs
SAME BASIC PRINCIPLE AS THE OLDER VEHICLE. THE OLDER ONES HAD ONE CAM SHAFT IN THE CENTER OF THE ENGINE THAT EACH LOBE OF THE CAMSHAFT PUSHED UP ON A LIFTER THAT IN TURN PUSHED UP ON A PUSH-ROD THAT PUSHED THE ROCKER ARM TO PIVET AND MAKE THE VALVE OPEN. WELL ON THE SINGLE AND THE DOUBLE YOU EITHER HAVE ONE CAMSHAFT OR TWO CAMSHAFTS ON TOP UNDER THE VALVE COVER INSTEAD OF INSIDE THE BLOCK. AS THE ENGINE IS TURNING THE CAMSHAFT LOBES ACTUALLY PIVOT THE ROCKER ARMS TO OPEN THE VALVES. DOHC HAVE TO BE TIMED TO EACH OTHER AS WELL AS THE CRANSHAFT.
2007-02-27 16:46:41 · answer #1 · answered by vic 2 · 1⤊ 0⤋
Vic is absolutely correct. The main reason for some cars having two camshafts is to separate the valves, and to angle the valve stems away from each other - which improves the flow of gases through the engine.
2007-02-28 03:10:35 · answer #2 · answered by Me 6 · 0⤊ 0⤋
Shawn has no idea. A single cam pushes on rocker arms that push the valves open. A double cam hass a camshaft directly above each bank of valves that pushes the valves open directly. OHCs can be simpler mechanically, but with no hydraulic lifters, can be more trouble to maintain.
2007-02-28 07:43:53 · answer #3 · answered by Nomadd 7 · 1⤊ 0⤋
dohc engines have 2 sets of valves instead of 1. the more valves means more gas being pushed into the cylinder giving you more horsepower.
2007-02-27 22:43:09 · answer #4 · answered by shawn s 2 · 0⤊ 0⤋