Head Rebuilding / Seat & Guide Install / Head Milling
We do a lot of head rebuilding (reconditioning) on vintage engines as correct casting and date codes can be critical, especially for automotive car collectors and high dollar car auction houses. We begin by rinsing the heads in the spray tank followed by disassembly and a closer inspection. If the heads pass inspection, we bake them in our high temp Large Block Cleaning Oven, media blast them and follow up with another spray tank washing.
New valve guides, either knurled thin-wall guide liners or full guides (bronze, cast or steel) are installed. Seats are then cut or replaced, depending on their condition. Pre 1964 exhaust seats require mandatory replacement, since the seats were not hardened. Unleaded fuel and unhardened seats do not get along well.
We cut most of our heads for positive style valve seals in order toi maintain oil control. We use a Sunnen Diamond Guide Hone to obtain correct valve stem clearances. Often the heads are resurfaced and washed. Angle Milling is available for certain restricted dirt track race classes. The valves are then lapped and installed, checking spring height for the particular application. Upon assembly completion valves are leak checked for proper seating.