Dnepr MT10-36 - Cylinders; Crankcase

When installing the cylinde r. s on the pistorJs, turn the compres-
siOn rin.gs so
that their locks are set apart in order to reduc e the
gas l eaka ge.
The pis • ton is linked with the connecting rod through floating pin
16, which is prevented from axia ,J displacement by two circlips 17
(Fig. 7), inserted into the ring grooves of the piston bosses.
Crankcase
Crankcase 3 (Fig. 5), cast from aluminium alloy, is the basic
structural component of the engine.
Inst a lled on and secured .to the - crankcase are the cylinders with
the heads and auxiliary mechanisms . In addition, the crankcase ser -
ves as an oil reservoir . Rotating inside the crankcase are the crank-
shaft and camshaft, at the front of it is a timing gear box, the gene-
rator is located a.t the top.
The bottom of the • crankcase is closed w ith a stamped sump 10.
Inserted between the crankcase and the sump is sealing gasket 11.
During engine operation, pa-rt of the gas mixture and of exhaus t
gases burst into the crankcase through the cl earances of piston rings;
also, as the pistons move to the bottom d ead centre, the V·O lu me of
the crankcase decreases, the gases filling the c rank chamber beco-
me compressed and force the oil outwards throu gh the pa cki ng
gland ,s and crankcase-and- •cover joints. To avoid this, t he crankca se is
provided with a fopced air supp tly. To open the crank chamber to the
at mospher e, when the pistons move down, or to shut it off, .when
the pistons move up, breather 15 (F ig. 6) is pro vided in the central
hole of the distribution box cover 40 .
The gases escaping from the • crankcase through the breath er al-
ways contain some water va · pour. There fo re, during operation in the
winter time, an ice lock may form in the rubber tube of the bre a-
ther,
thus obstruCting . the gas outlet a nd causing oil leakage th roug h
t
he packing glands.
To prevent this from happening, it is advisa i ble to remove the
rubber tube when oper ating the ve hi cle in winter time at a te mpe-
r
ature 0 °C and below.
Cylinders
Engine cylinders 6 (Fig. 7) are similar in design, interch ange-
able, (bimetallic aluminium jacket with a cast iron liner). The lower
part of the cy1 linder has a flange with holes passing through all the
fins. These holes are intended for anchor studs to secure the cylin-
ders and the cylinder heads .to the ·c rankcase. The upper pa . rt of the
cyli nder is fitted with a collar • which · enters the groove of the head .
Plac ed between the cylinder and the head is sealing gasket 4.
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