Tag Archives: small engine cams

About Valve Train Components

We hope here to clear up some confusion about valves, vale springs, retainers and valve locks for Honda GX small block engines and the Clone engine. There are 3 basic types of valve and valve spring retaining systems used on the engines. The first is the off set clip type standard type retainer system.On the Clone and Honda there are two types of retainers used on the intake and exhaust valve. The intake valve retainer is the one on the right. The retainer on the left is larger in the centre as the exhaust valve uses a lash cap between the rocker arm and the top of the valve.


When using standard retainers the valve springs chosen should never be excessive as the standard retainer is really only designed to accept around 10 lbs.


Note the wire diameter of a standard valve spring, we would never recommend a valve spring with an installed pressure over 18 lbs ever be used. The standard retainer is a pressed tin cap and if you must run valve springs with additional pressure they should be replaced regularly and the rocker arm stud threads should be checked as it is not unusual for the studs to pull out from the cylinder head.


Pictured above is a standard Honda valve on the left and a swirl polished Aussiespeed stainless steel performance valve on the right. Note the top of the valve where the retainer sits. The stock valve uses the off set style retainer. The valve on the right uses a 3 piece retainer and 2 locks. The valve on the right can be used with both a dual or single valve spring.

This picture show two different types of retainers with the black ones that suit dual springs and the lower silver retainers for single valve springs. If you look at the collets / valve locks you will notice that the groove on the inside is in two different positions. The top valve locks are for dual springs and must be matched with the retainers and the smaller bottom locks must be matched to the retainers for single springs.


Pictured above are a pair of single valve springs, depending on the wire diameter, number of coils and what is called the installed height of the valve spring when the valve is fitted to the cylinder head with the valve closed the amount of pressure required to lift the spring of the seat.


To increase the installed pressure of a valve spring a shim can be fitted between the spring and where it is seated on the head, this compresses the spring and increases the opening pressure.


Depending on the lift of your camshaft some times a single valve spring will compress to quickly and when this happens a second spring can be fitted inside the outer spring. These are called dual springs and when used on a valve with the same installed height can boost pressure and are commonly used with camshafts with aggressive ramp rates. The ramp is the side of the cam shaft before the nose { small tip of the cam}. Dual springs can note be used with standard clone / honda retainers or with a after market retainer that doesnt have the provision to have a second spring to sit on a flat surface on the retainer.

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