Technical Bulletin: Valves
Engine valve is a precision component and, as such, it should be handled with extreme care, avoiding blows that can damage the valve stem as well as the valve seat.
Engines produced starting in1994, injected and controlled electronically, are being increasingly used with these and other mechanical components. For this reason, the alteration and recovery of parts invariably result in serious losses to operators and automotive repair shops.
Our recommendations are as follow:
01. Do not mark with a punction the valve’s upper surface in order to identify its position on the cylinder head. This procedure will cause a dislocation of the verticality of the cylinder head and the valve stem, causing a poor fit with the valve housing, resulting in the burning and rupture of the valve. Such a procedure will result in a loss of guarantee.We recommend using a felt pen to mark spots for identification.
02. Do not try and repair a valve seat by grinding or abrasion. This procedure will distort the circularity, concentricity and angulation of the valve, making for a poor fit with the cylinder head’s valve seat and resulting in leaks, burning and rupture, with consequent engine power loss. We recommend changing out the valve.
03. Do not use valve springs with lengths (mm) that do not comply with the manufacturer’s specifications. This procedure will result in the in fluctuations and catching of valves, ruptures and smashing against other pistons, causing irreparable damage to the engine. We recommend that you change out of all springs.
04. Do not reduce the length of the valve, lowering the stem’s tip. This procedure results in bad functioning in the length of time the valve is open, causing flutuations, locking and ruptures due to pistons smashing into one another. We recommend changing out the cylinder head’s valve seat.