The two types of engine valves are intake and exhaust.

发动机气门的二种型式是：进气口和排气口。

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This paper holds a discussion on methods of adjusting in line engine valves and recommends a new method for that.

本文对直列式多缸发动机气门调整方法进行了探讨，推荐一种新的方法。

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The invention relates to a method for making a titanium-based automotive engine valves using powder metallurgy process, and the automotive engine valve stem, engine valve and method of producing both.

本发明涉及利用粉末冶金工艺制造钛基汽车发动机气门的方法。公开了汽车发动机气门杆、发动机气门以及二者的制造方法。

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Ford's first attempt at a genuine four-wheel vehicle, which he called the Quadricycle, used valves adapted from a steam engine and didn't have a reverse gear.

WSJ: Book Review: I Invented the Modern Age | Henry Ford

It's an overhead valve engine with a single camshaft that uses push rods to open and close the 16 valves.

FORBES: The Engine That Could