With today's newer engines, the service intervals for certain maintenance items can be longer than most people will even keep their cars. About the only routine maintenance that has to be performed are oil changes. For those of us who tend to drive above and beyond what is considered normal, with autocrosses, track events, frequent spirited driving, and the like, additional maintenance is more like a religion than a requirement. Within this realm of maintenance is inspecting the valve clearance and adjusting as necessary.

Let's take the K20A2 engine from the RSX Type S, for example. This service isn't recommended until 110,000 miles. Compared to the RSX's predecessor, the Integra, which required a valve adjustment every 30,000 miles (15,000 miles in severe conditions), this is an eternity.

It is difficult to believe that even on such a sophisticated engine as is in the RSX that the valves will remain within spec for a duration of such proportions. It's even harder to imagine such a feat after 110,000 miles of grueling punishment with extended high RPM, full throttle sprints around race courses.

Checking the valve clearance (and adjusting it if necessary) is relatively simple on an overhead camshaft engine, provided you have the courage to open up the engine a bit. Once the valve cover is removed, everything is well within reach. It is important to maintain valve clearances that are within spec if you're trying to squeeze every last ounce of performance from your engine. After all, the valves are what get the air/fuel mixture into and out of the cylinders. Opening the valves too much can cause a loss of compression, and not opening far enough reduces the amount of mixture that will be burned or expelled.

The goal of this article is to show how to measure and adjust the valve clearance on a Honda dual overhead cam engine. Since the principles are the same, the methods applied here can be carried over to other engines with slight modifications.

Tools Needed

• Angled feeler gauge (click for picture)
• 10mm socket and driver
• Flathead screwdriver
• Torque wrench with 7 ft./lb. accuracy
• Honda valve adjustment tool (or similar) RECOMMENDED
• Jack (factory is OK)
• Valve cover gasket & liquid gasket (possible)

Copyright 2003, Temple of VTEC