Mitsubishi S4S-D — Facing Up Valves and Valve Seats
Maintenance · Cylinder head
For the Mitsubishi S4S-D, from the Mitsubishi service manual.
Applies to: Mitsubishi S4S-D, Mitsubishi S4S engine
Before you start
- Do not apply compound to the valve stem.
- Do not rotate the valves with compound applied when pressing them against the seats.
Procedure
- Apply compound uniformly and thinly to the valve surface.
- Face up valves and seats with the valve lapper, rotating the valve little by little.
- Remove compound with cleaning oil.
- Apply engine oil to the contact surface and face it up with oil.
- Check the contact of the valve faces.
Tools required
- Valve lapper Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Use medium-grain compound (120- to 150-mesh) first, then fine-grain (260-mesh or finer)
Source: Mitsubishi service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.