Inspection - Ford Ranger Maintaince And Repair Manual

INSPECTION

Now that all of the cylinder head components are clean, it's time to inspect them for wear and/or damage. To
accurately inspect them, you will need some specialized tools:
• A 0−1 in. micrometer for the valves
• A dial indicator or inside diameter gauge for the valve guides
A spring pressure test gauge
•
If you do not have access to the proper tools, you may want to bring the components to a shop that does.
Valves
The first thing to inspect are the valve heads. Look closely at the head, margin and face for any cracks,
excessive wear or burning. The margin is the best place to look for burning. It should have a squared edge
with an even width all around the diameter. When a valve burns, the margin will look melted and the edges
rounded. Also inspect the valve head for any signs of tulipping. This will show as a lifting of the edges or
dishing in the center of the head and will usually not occur to all of the valves. All of the heads should look
the same, any that seem dished more than others are probably bad. Next, inspect the valve lock grooves and
valve tips. Check for any burrs around the lock grooves, especially if you had to file them to remove the
valve. Valve tips should appear flat, although slight rounding with high mileage engines is normal. Slightly
worn valve tips will need to be machined flat. Last, measure the valve stem diameter with the micrometer.
Measure the area that rides within the guide, especially towards the tip where most of the wear occurs. Take
several measurements along its length and compare them to each other. Wear should be even along the length
with little to no taper. If no minimum diameter is given in the specifications, then the stem should not read
more than 0.001 in. (0.025mm) below the unworn portion of the stem. Any valves that fail these inspections
should be replaced.
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HOW TO USE THIS BOOK
Valve stems may be rolled on a flat surface to check for bends
INSPECTION