V-Pipe And In-Line Muffler; Water Lift Exhaust System - Mercury MerCruiser Product Applications Manual

V‑Pipe and In‑Line Muffler
b

Water Lift Exhaust System

These engines are equipped with a wet exhaust system in which exhaust is mixed with
water in the exhaust elbows. This cools the exhaust and allows the use of heat resistant
rubber hose on the outlet side of the system. These specifications must be observed by
the OEM and muffler manufacturer when designing and installing the exhaust system:
• Through the prop exhaust utilizing the Y‑pipe is the desired system on all models except
the 496 Mag.
• Heat resistant exhaust hose that complies with specifications SAE J2006 or UL 1129
must be used (ABYC standard).
• Exhaust hoses should be no smaller than the minimum sizes. Larger hoses should be
used on applications with long hose runs.
Model
90-863758060 AUGUST 2006
e f
c
d
a
a - Water line
b - Minimum exhaust elbow height
with maximum load
c - Exhaust back pressure check
point
d - Resonator
e - 46 cm (18 in.) minimum between
exhaust elbow and Y‑pipe
f - Minimum of 10° downward slope
in the first 46 cm (18 in.) 46 cm
(18 in.)
Dual outlet system
h
g
i
g
j
Typical
g -
h -
i -
j -
k -
l -
Minimum Exhaust Hose Size
Dual hose portion
Exhaust System
k
l
15635
Y‑pipe
30°–60° angle at junction
3° downward slope minimum
Muffler
External flappers
Drain fitting
Single outlet system
Single hose portion
Page 6A-11