Hudson 1948 - 1952, Service Manual

Page: 84 / 333

3 - 42 ENGINE
VALVE TIMING
6 Cylinder
Inlet open 26.7° BTC
Inlet closes 91.9° ABC
Exhaust opens 67° BBC
Exhaust closes 40.3° ATC
8 Cylinder
Inlet opens 10°-40' BTC
Inlet closes 60°-0' ABC
Exhaust opens 50° BBC
Exhaust closes 18°-44' ATC
VALVE TIMING CHECK
6 and 8 Cylinder
To determine if valve timing is correct without disman-
tling the engine, the following procedure may be used:
1. Remove the front tappet cover and adjust the tappet
clearance of #1 intake valve to .010 with engine hot or
.012 with engine cold.
2. Insert a .002" feeler gauge in #1 intake tappet and
rotate engine in direction of rotation until exhaust
valve begins to close. Continue to rotate engine very
slowly until a light drag is felt on the feeler gauge.
3. At this point, inspect the timing marks on the flywheel
through the opening in the rear engine support plate. (No.
6 ready to fire.)
FIGURE 49
The engine is correctly timed when the first of the five
timing marks is approximately 5/8" above the index of the
timing hole shown as "A", Figure 49. When checking
eight-cylinder valve timing, dimension "A" should be 9/16".
4. Reset No. 1 intake valve to recommended clearance of
.010" hot or .012" cold and reInstall tappet cover.
VALVE MAINTENANCE
If valve tappets, with proper clearance, a re noisy the
following points should be checked:
1. Tappets loose in their guides.
2. Tappets not properly rotating causing uneven wear on
tappet faces.
3. Weak valve springs.
4. Valve sticking in valve guides.
5. Valves loose in valve guides.
6. Valve springs cocked or not seating properly.
7. Warped valve.
8. Valve seat and guide not in alignment.
CYLINDER BORING OR HONING
Careful washing and careful protection before recon-
ditioning the cylinder bores will save a great deal of
expense later.
Crankshaft bearings, camshaft bearings, connecting
rod bearing surfaces on the crankshaft, crankcase walls,
in fact the entire part of the engine below the bottom of
the cylinder bores must be protected from any particles
of grit, chips, etc.
After reboring the cylinders or honing them, it is
necessary that they be thoroughly washed.
All traces of abrasive material will have to be
removed or extremely rapid wear of the new parts
will result.