(+ ' % " " % -
(( (* (.
& % " "
$ " "
the more common points such as valve springs, valve rockers, push rods, and impeller shaft. Chromium plate is use don the under side of the inlet valve head and on upper piston compression ring outside diameters. Lead is used in the master-rod bearing bore.
A minor design feature almost universally used is threaded pins to locate busings. The bushing and part in which it is installed are tapped after assembly, the pin screwed into place and then machined flush inside and out. This is even found in the piston pin eye of the connecting rods. The resulting sharp corners would, of course, worry us greatly.
Cylinders are numbered by banks in the direction of engine rotation. Thus, number 1F is at the bottom of the front bank between 4R and 5R, and number 1R is at the top of the rear bank.
Design Details CRANKCASE — The crankcase (Fig. 8) is a typical three-section 17S aluminum-alloy case split on the centerline of the cylinder banks and held together by means of one 0.475- in. diameter through bolt between each cylinder. Cylinder decks are approximately 0.88 in. thick at the bore and incorporate twelve equally spaced studs for cylinder attachment. These studs are approximately 3/8-
20 at the crankcase
nut end, 7/16-17 in the
diameter neck. Cylinder-deck height is 9.8 in. approximately from the crankshaft axis. The three main crankshaft bearings fit bearing retainer rings shrunk and pinned into the crankcase diaphragm hubs.
Bearing bores in the crankcase are: front, 6.56 in., center 11.13 in., and rear 6.3 in. Bearing fits at this point appear to be in accordance with conventional American practice. The front bearing retaining ring only is