Cleaning, cylinder heads are magnafluxed (to detect any crack or flaws),
all bolt holes are chased with a tap (to assure the threads are good),
rocker studs are checked for wear (and replaced if needed) and gasket
areas receive additional cleaning. (Note: all cylinder heads are resurfaced
at a later time.) Since we use oversize valves where available, all
guides are reamed to .015 oversize. Any guide holes that do not clean
up receive a new guide. Any application that oversize valves are not
available receive all new guides (we do not use any guide liners).
After the guide work is complete, the seats are 3-angle cut and a
vacuum test performed to assure that the valve and seat are correct.
Heads are then re-surfaced to assure it has a good surface for gasket
All heads then receive a final quality check to be sure all holes
have been chased, the studs are good, all seats and guides are correct,
and the surface is good. Heads then receive a final cleaning, and
Final assembly is with all 'new' valves, 'new' valve springs, 'new'
seals and keepers (valve locks). After assembly, the heads are vacuum
checked to assure the valves & seats have no leaks. Heads are
then sent to the engine assembly area, or stored on the shelf until
needed for production or a sale.