CMI Tailpipes

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CMI Tailpipes

Fully-polished, precision-matched CMI tailpipe sets include pipes for both port and starboard exhausts. CMI Tailpipe sets include all of the V-band clamps, sealing gaskets, retaining bolts, jumper hoses and hose clamps required for installation. All CMI tailpipe sets are fully polished. Exhaust tips and connecting hoses are not included.

CMI Tip-Style tailpipes are standard for most exhaust applications when connecting to existing transom tips. For proper application and fit, header collector height and transom hole layout are both measured and used to determine if Tip Style tailpipes are required. A rubber connector hose is required to connect Tip-Style tailpipes to the transom tips. Use the CMI Exhaust System Build Guide to determine if CMI Tip Style tailpipes are required.

For applications that pose a risk for water reversion, CMI recommends using thru-hull tailpipes. Water reversion can occur in applications where tailpipe cooling ports are located near the engine exhaust ports. In these cases, exhaust scavenging draws cooling water from the tailpipe into the engine, which can cause premature engine failure. Thru-Hull tailpipes will minimize the potential for reversion. In extreme applications where engine positioning creates a risk of water reversion, a “completely dry tailpipe” is required. Fully-welded CMI Completely Dry tailpipes divert all water entering the system to an external dump valve which helps prevent the water from flowing into the engine.

All CMI tailpipes are designed to fit standard Mercruiser and after-market Bravo Drive or transmission applications.

Tailpipe Measurement Guide (PDF - 193KB)
Download CMI Exhaust System Build Guides
CMI Header and Tailpipe Accessories

How to Measure Hole Height
CMI Tailpipe Measurement Guide

All vertical dimensions are for standard height manifolds and taken on the outside of the transom with ruler flat against transom. CMI requires precise measurements ensure system fit. Plus or minus transom measurements indicate minimum and maximum dimensions in which tailpipe transom holes may be specified. Radius angles are an additional charge. See Measurement Guide for instructions to measure tailpipe installation.

Correct Measurement Method

Big Elbow Top & Big Tube Race Systems

Bravo Drive Applications

(dimensions listed are for 9.8" deck block & standard GM head castings)

Thru-Hull     Transom Hole Locations (See Chart Above)
Part Part Number A B C D
Race Straight Pipe
Tailpipe set (straight) polished 39390 13 5/8 ±1/4" 13 5/8 ±1/4" Varies Varies
Race One Angle Pipe
Tailpipe set (straight) polished   13 5/8 ±1/4" 13 5/8 ±1/4" Varies Varies
Race Custom Two Angle Pipe
Tailpipe set (straight) polished 39350 13 5/8 ±1/4" 13 5/8 ±1/4" 13 7/16 ±3" 13 7/16 ±3"
Tailpipe set (offset) polished 39430 13 5/8 ±3" 13 5/8 ±3" 13 7/16 ±3" 13 7/16 ±3"

Tailpipe Measurement Guide (PDF - 193KB)
Download CMI Exhaust System Build Guides
CMI Header and Tailpipe Accessories

Standard Elbow Top & Sport Tube Systems

Bravo Drive Applications

(dimensions listed are for 9.8" deck block & standard GM head castings)

Transom Tip     Transom Hole Locations (See Chart Above)
Part Part Number A B C D
Standard MerCruiser Bravo Hole Opening
Tailpipe set polished 39750 13 5/8 ±1/4" 13 5/8 ±1/4" 13 7/16 ±1/4" 13 7/16 ±1/4"
Straight Pipe
Tailpipe set polished 39650 13 5/8 ±1/4" 13 5/8 ±1/4" E-Tops
14±1/4"
Sports
11 9/16 ±1/4"
E-Tops
14 11/16±1/4"
Sports
12 1/2 ±1/4"
One Angle Pipe
Tailpipe set (straight) polished   13 5/8 ±1/4" 13 5/8 ±1/4" Varies Varies
Custom Two Angle Pipe
Tailpipe set (straight) polished 39790 13 5/8 ±4" 13 5/8 ±4" 13 ±3 13 ±3
Tailpipe set (offset) polished 39830 13 5/8 ±4" 13 5/8 ±4" 13 ±3 13 ±3
Double Miter Surcharge for C&D between 5" & 10" 13001        
S-Pipe
Tailpipe set (straight) polished 39870 13 5/8 ±1/4" 13 5/8 +10 / -2 C and D + 2" above crank CL ±3
Tailpipe set (offset) polished 39690 13 5/8 ±10 /-2 13 5/8 ±10 /-2 C and D + 2" above crank CL ±3
Thru-Hull      
Part/
Part Number
Part Number A B C D
Straight Pipe
Tailpipe set polished 39420 13 5/8 ± 1/4" 13 5/8 ± 1/4" E-Tops
14 ±1/4"
Sports
11 9/16 ±1/4"
E-Tops
14 11/16 ±1/4"
Sports
12 1/2 ±1/4"
One Angle Pipe
Tailpipe set polished   13 5/8 ± 1/4" 13 5/8 ± 1/4" Varies Varies
Custom Two Angle Pipe
Tailpipe set (straight) polished 39380 13 5/8 ±1/4" 13 5/8 ±1/4" 13 7/16 ±3" 13 7/16 ±3"
Tailpipe set (offset) polished 39460 13 5/8 ±4" 13 5/8 ±4" 13 7/16 ±3" 13 7/16 ±3"
Y-Pipe (Straight Stinger)
Tailpipe Set 4 1/2" Collector headers (radiused) polished, Rope Seal Style 39120
Tailpipe Set 4" Collector headers (radiused) polished, "O" Ring style 39130
Y-Pipe Side View Y-Pipe Top View

Tailpipe Upgrade Garage

each diameter increase
Part Part Number
Stepped Tailpipe Addition
Stepped tailpipe option for one set 39160
Note: The Stepped Tailpipe charges are an addition to prices listed in each tailpipe section.
Stepped Tailpipe Side View Stepped Tailpipe Top View
Radius angles replacing miters
Radius angles replacing miters  
 
Transmission-Style Upcharge  
Completely Dry Upcharge  
Additional Charge Restrictors
For Mercury Racing 525EFI/600SC/700SC
 
Forward Engine Tailpipe Stagger & Triple
Support bracket system required for all forward engine applications
 
Part Part Number

Forward Engine Tailpipe Support Systems

Clamp On Head Mount 13000
Clamp On Transmission Mount 13001
Weldo On Head Mount  
Weld On Transmission Mount  
3/4" NPT Female Fitting Installed into Tailpipe
For External Cooling Water Dump
39990
1" NPT Female Fitting Installed into Tailpipe
For External Cooling Water Dump
19300
Sensor Couplings for Oxygen Fitting
Installed In Tailpipe or Header
41400
Oxygen Plug M18-1.5 19670
Sensor Couplings for Pyrometer Fitting
Installed In Tailpipe or Header
41401
Pyrometer Plug .125 NPT 19800

Tailpipe Measurement Guide (PDF - 193KB)
Download CMI Exhaust System Build Guides
CMI Header and Tailpipe Accessories