465 Engine Valve Adjustment Method?
3 Answers
465 engine valves use the cylinder-by-cylinder adjustment method. The specific steps are as follows: 1. Adjust cylinder one: When cylinder one is at the compression top dead center (methods to determine top dead center include turning the flywheel with the key on until the high-voltage wire of cylinder one sparks, then slightly reversing the flywheel. Alternatively, look for the compression top dead center mark of cylinder one at the bottom of the flywheel housing), adjust valves 1, 2, 3, and 6. 2. Adjust cylinder four: When cylinder four is at the compression top dead center, adjust valves 4, 5, 7, and 8. The method to determine if cylinder four is at compression top dead center: turn the flywheel until the high-voltage wire of cylinder four sparks, then slightly reverse the flywheel to adjust.
The minivan in my family uses a 465 engine, and I just adjusted the valves myself last month. Before adjusting the valves, wait until the engine is completely cooled down, and clean the surrounding dust after removing the valve cover. The key is to accurately locate the top dead center (TDC) of the piston: rotate the crankshaft pulley, and when the mark on the flywheel aligns with the indicator, it's the compression TDC of the first cylinder. Use a feeler gauge to adjust the intake and exhaust valve clearances of cylinder 1, both with a standard of 0.15 mm. Loosen the lock nut and rotate the adjustment screw until the feeler gauge can be pulled out with slight resistance. Then, rotate the crankshaft in order to adjust the other cylinders, turning 180 degrees each time to adjust cylinder 3, 4, and 2 sequentially. Finally, all nuts must be tightened and the clearances rechecked. It's best to inspect the sealing ring before reinstalling the valve cover. The whole process isn't difficult, but your hands need to be steady—if the feeler gauge is too tight, it can easily cause valve noise.
Adjusting the valves on a 465 engine requires attention to sequence and precision. Always start the operation when the engine is cold, with a feeler gauge and wrench ready. First, position the No. 1 cylinder piston at the top dead center of the compression stroke, which can be confirmed by observing the flywheel markings while rotating the crankshaft. After adjusting both valves on the No. 1 cylinder, don't rush to remove the tools. Rotate the crankshaft half a turn to adjust the No. 3 cylinder, then another half turn to reach the No. 4 cylinder, and finally adjust the No. 2 cylinder. Each valve adjustment must ensure a 0.15 mm gap, with slight resistance when inserting the feeler gauge. A common mistake beginners make is turning the adjustment screw while tightening the lock nut, so always stabilize the screwdriver in the opposite direction when tightening. After finishing, perform a no-load test. If the valve tapping noise increases, the gap is too loose. This meticulous job can be completed in about half an hour.
