QuestCraft 8" Universal Adjustable Valve Spring Compressor Automotive Engine Repair Tool 8" adjustable valve Spring Compressor designed to compress valve springs on overhead valve engines. The direct action compressor lever gives better visibility of valve spring retainers There is a jaw opening of 1-3/8" to 5-5/8" (35mm to 142mm) and a throat clearance of 5-7/8" (150mm)