Dnepr MT10-36 - Valve Timing Gear; Cylinder Heads; Care of the Crank Gear

Cylinder Heads
Cylinder heads 3 and 12 a re manufactured from aluminium alloy
and are furni.shed on t he outside with fins to increase the cooling
a-rea. The combustion chamber is of . the hemispherical type. Pro vided
on the head, at the sid-e opposite to the combustion chamber, are
four !brackets with the rockers fitted in their holes. In the upper part
of the head is a threaded opening for the spark plug.
Care of the Crank Gear
When ca rrying out a daily inspection, dean the c- rankcase, cylin-
ders, and cylinder heads to remove dirt and dust. Alrso, keep the fins
clean, since dirty fins worsen the cooling conditions of the engine.
Periodically tighten up the nuts fastening the cylinders heads, the
bolts fastening t he front cover of cra nk case and the covers of cy -.
linder heads. Make sure that the . re is no oil leakage and the crank
chamber is air-tight. If the air-tightness is disturbed as the r· esult of
the paper or rubber gaskets of the packing glands being incorrectly
installed or dam ag ed, an air in1 leakage will take place and the pre s-
su . re in the crankcase will rise. This will cause not only an increased
oil leakage at the det · achable joints and through packing glands, but
also premature con taminat ion of oil and excessive wear of engine
components.
A fter eve ry 10000 km run, clean the combu stion chambers to re-
m ov-e carbon deposit. The presence of carbon deposit in the engine
causes knocking which reduces the service life of the engi ne.
If the oil cons ump tion by the engine ex• ceeds 0.25 1 per 100 km
run, the piston rings must be repla ced.
Valve Timing Gear
The valve timing gear regul · ates the opening and closing of the
ex h aust and inl et valves at the · required moments of crankshaft tur-
ning. Th e va lve timing gear consists of cams haft 3 (Fig. 9), tappet s
4 (Fig. 5), push rods 1, r ockers 21 (Fig . 7) and 29, adjusting bolts
23, check nuts 24, exhaust valve 22 and admission valve 18 with
caps 20, sp ring s 26, 27, re tai ner s 25, 28, and slide blocks 30. Fitted
at the front of the camshaft is driven pinion 2 (Fig. 9) which is
engaged with driving pinion 4 of the valve gear and with gear 1 of
the generator drive. The camshaft is installed in the crankcase in
two ball bea rings 19 and 23 (Fig. 6).
Valve Timing
The admission valve ope ns as the piston does not re ac h the upper
dead centre by 10° (crankshaft turning angle) which is th e admis-
sion lead, and closes 50 ° after the piston passes the b otto m dead
ce ntr e, which is admission closing lag (Fig. 8). Th e admission - du-
r a tion is 240°·
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