How to check valve to valve clearance?

Hi there HPA.

How can someone check valve to valve clearance, apart from piston to valve clearance?

Also what's the lobe separation angle of Honda's B16B camshafts. Generally can someone calculate the LSA of camshaft that has Vtec?

Thanks!

There's a few options when it comes to checking valve to valve clearance. One of the easiest is with a bore scope with a 90 degree attachment so you can watch the valve motion through the spark plug hole as the engine is turned through a full cycle. An alternative that takes a lot more work is to perform a dummy build where you leave a piston and rod out of a cylinder. You can then turn the engine over and view the valve to valve proximity from the underside of the block. Again a bore scope makes this easier as you'll be looking around the conrod journal on the crankshaft which can compromise visibility.

The lobe separation angle is the angle in cam degrees between the maximum lift point of the intake and exhaust cam lobes. In a DOHC the LSA isn't fixed and you can influence it by advancing/retarding one cam with respect to the other. You can calculate the LSA provided you have cam data for the high lift cam profile from the cam manufacturer, or you can measure it yourself with reasonable accuracy.