What is the general valve clearance value?
2 Answers
The standard valve clearance is as follows: 1. The clearance of the intake valve is generally within the range of 0.20mm to 0.25mm. 2. The clearance of the exhaust valve is larger than that of the intake valve side due to thermal expansion, so the clearance naturally needs to be larger, generally between 0.29mm and 0.35mm. Here are some related introductions: 1. If the valve clearance is too small, the engine may leak air due to the valve not closing tightly in the hot state, resulting in a decrease in power and even burning of the valve. 2. If the valve clearance is too large, it will cause impact noise between the transmission parts and between the valve and the valve seat, and accelerate wear. At the same time, it will also reduce the duration of the valve opening, worsening the cylinder's air intake and exhaust conditions.
Valve clearance is typically measured when the engine is cold, usually ranging between 0.15mm to 0.30mm. Specifically, for gasoline engines, the intake valve clearance may be around 0.20mm, while the exhaust valve clearance is approximately 0.25mm. Diesel engines generally have slightly larger clearances, commonly between 0.25mm to 0.35mm. I've learned this from hands-on repair experience, as I always use a micrometer to calibrate when tuning engines for customers. If the clearance is too small, valves may not close properly, causing air leaks or burning; if too large, it increases noise and fuel consumption. Therefore, it's advisable to consult the vehicle's owner's manual or seek professional diagnosis, as specifications can vary significantly between models like older Toyotas and newer Hondas. Regular checks are crucial to avoid major engine overhauls.
