How to adjust the valves of the Aowei 11-liter 460?
3 Answers
According to the cylinder firing order, after determining that a certain cylinder's piston is at the top dead center position of compression, the intake and exhaust valve clearances of this cylinder can be adjusted. Turn the flywheel slightly in its original direction (to prevent the cam from pushing the pushrod), and then the valve clearance can be adjusted. This is because the valves open once every two revolutions of the flywheel, so the cam will not push the pushrod.
Ah, talking about valve adjustment reminds me of the time I helped my friend with that Aowei engine. This big 11-liter, 460-horsepower beast requires letting the engine cool down first before adjusting the valves, because the clearance changes when it's hot, and getting it wrong can easily cause problems. First, remove the valve cover—don't yank it hard, or you might damage the screws. Then, manually turn the crankshaft clockwise, watching for the markings to find the compression top dead center position, aligning it with the first cylinder. Remember, Aowei diesel engines usually use a feeler gauge to measure clearance—check the standard value in the manual, around 0.3mm is common. When measuring, insert the feeler gauge gently; don't force it. If the clearance is off, loosen the screws to adjust, then tighten and recheck a few times. The whole process requires care—too much clearance and the engine will knock, too little and the valves will stick. If they burn out, repairs are a hassle. I also recommend wearing goggles and gloves—engine oil splashing into your eyes is no joke. Regular adjustments can extend engine life; checking once a year is enough.
Every time I adjust the valves on a heavy-duty truck, I treat it as a small challenge. For the Aowei 11-liter 460 engine, the key to valve adjustment is finding the right position. Here's how I do it: First, park the truck on level ground and let it cool for half an hour after turning it off. Then, remove the valve cover to expose the cylinder head. Manually rotate the crankshaft by hand while keeping an eye on the flywheel marks or timing belt pulley indicators until you reach the compression top dead center (TDC). Next, use a feeler gauge to measure the valve clearance of the first cylinder—the ideal gap is usually between 0.25-0.35 mm. If it's too loose or tight, loosen the adjustment screw and readjust, then move on to measure other cylinders. Why emphasize precision? If the clearance is off, the engine will immediately run rough, idle unevenly, and fuel consumption will spike. The tools needed are simple: a feeler gauge set costs just a few bucks, plus a wrench is all you need. After finishing, reinstall the cover and listen for any unusual noises during a test drive—if it sounds clean, you're good. Don't skip this step; it's the frontline defense against major overhauls.
