Collector Inlet And Outlet Specifications; In-Line Muffler - Mercury MerCruiser Product Applications Manual

Exhaust System
• Exhaust back pressure must meet the required specification. (See Exhaust Back
Pressure Test)
IMPORTANT: Exhaust collectors must drain sufficiently during engine shutdown and idle
to provide the drainage necessary for these operational conditions. Use the following
specifications when designing the collector.

Collector Inlet and Outlet Specifications

1. The inlet hose for the collector must be placed above and within 180° of the horizontal
centerline of the collector.
2. The outlet hose of the collector must be placed below the horizontal centerline of the
collector and within 90° of the vertical centerline of the collector.
In‑line Muffler
b
Page 6A-8
Models
All gasoline powered engines
f
c
e
a - Collector
b - Vertical center line
c - Horizontal center line
c
a
Typical single engine inboard without water standing in muffler
b d
e
d
f
g
Exhaust Back Pressure
1 psi (7 kPa) Minimum
2 psi (14 kPa) Optimal
11 psi (76 kPa) Maximum
a
15540
d - Inlet side of collector
e - 90° range for placement of collector
outlet
f - 180° above horizontal centerline
i
h
15541
90-863758060 AUGUST 2006