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The Magical Mystical Weber DCOE

The
Numbers
Tuning and
Jetting
Do I Run a
Single 45
or Dual 40's?
Tuning and 
Service PDF

(2 meg file size)
Weber
Resources
on the Internet
User Photos
and jettings
  Adjusting
Twin DCOE's
The Fuel
Flow Path
Physical
Dimensions
Excellent Article
by Mickey Luaria

Virtual
Tour

Rasors Fuel
Flow Pathes

The Jetting
Calculator

---------

An email from
a Racer

     (and some DGV stuff too)

DCOE 45 (152)

The DCOE numbers....

    .....a project in process. data is in complete and constantly being updated.......

       From the eyes, ears, minds, and typing fingers of the members of the Triumph Spitfire e-mail List, The Editors of the Triumph Tune Catalog, with a special thanks to those people submitting photos and jetting info that makes these pages possible, I bring you a compilation of all the info I've been able to find concerning the initial setup of Weber DCOE carburetors for the 1500 Triumph Spitfire (and now others...post 11/99).

       There are many factors that can effect the initial settings that work best for you. They vary due to driving habits, various engine modifications, state on wear, etc ,etc.

       Get your hands on a copy of 'Weber Carburetors' by Pat Braden, ISBN #0-89586-377-4. It covers dis-assembly and rebuild, tuning, and complete descriptions of all the sub-sections of the inner workings of the DCOE, among others. Also the Haynes Weber Manual (?? ISBN #???) is a very good source of info. A third source is the Weber Factory Overhaul Manual (Weber part number #95.0022.35). You can order this book from The Performance Parts Warehouse   Another excellent sources is Advanced Performance Products they carry a complete line of ram pipes, jets, air filters ands ancillaries for the DCOE. (no financial interest in any of these sources, these as named are simply recent sources still avail.)

       The following tables are beginning settings only and are not the only combination of settings that might work for you.

  DCOE 40 DCOE 45
Item Road Fast Road Max.  
Choke 28 30 33 33
Aux. Venturi 4.5 4.5 4.5 4.5
Main Jet 115 115 125 190
Emulsion Tube F16 F16 F16 F9
Air Jet 165 155 165 175
Pump 35 35 35 40
Idler Jet 45F8 45F8 45F9 45F9
Ex. Valve 0 0 0  -
This table was supplied to me By Glen Trunnell in his much appreciated attempts to help answer my questions. I believe this information is from the 'Triumph Tune' Catalog and avail through Moss International.

Again...it's here as a reference only to possible/probable starting settings.

Item Using 1
40 DCOE 18
Using a pair of
40 DCOE 18
Using  1
45 DCOE 13
Choke 28 30 34
Aux. Venturi 4.5 4.5 3.5
Main Jet 125 115 150
Emulsion Tube F16 F16 F2
Air Jet 160 170 175
Pump 50 50 50
Idler Jet 45F9 45F9 55F8
Accel. pump (jet) 50 50 50
Ex.Valve 50 50 50
This table I built from info found in books, internet sites, tech articles, and word of mouth.

Again...it's here as a reference only to possible/probable starting settings.

Well... this is what was run on my single
DCOE 45 152 attached to my 1978 Spitfire (Punkin- see photo spec page).
Choke 34
Aux. Venturi 4.5
Main Jet 145
Emulsion Tube F16
Air Jet 155
Pump 45
Idler Jet 55F8
Ex.Valve 40
Well at the moment these numbers are working, mostly because this is what was in the '78 when I bought it. I am running a Kent Mild Road Cam. A Dial micrometer (during a valve adjustment) says my valves are opening(being pressed in) 0.340". The cam lift would have to be divided by whatever the rocker ratio is to define the actual cam lobe lift. ( I guess this is something else I need to look up.)

     Supplied to the manafacturers to be used as OEM carburation for each of the cars listed, this table shows the factory jetting info as configured as 'stock'.

Model 40

40

40

45

45

45

45

45

style (or sub model #)

18

32

2

9

9

13

13

15/16

mfg. part number

19550.013
19550.014

19550.043
19550.044

18550.005

19600.017

19600.027

19600.003

19600.022

19600.004
19550.005

Choke

30

32

33

36

38

38

34

38

Aux. Venturi

4.5

4.5

4.5

4.5

3.5

5

3.5

5

Main Jet

115

130

115

145

175

160

130

125

Emulsion Tube

F11

F9

F16

F16

F2

F16

F2

F9

Air Jet

200

200

150

155

170

170

175

170

pump jet

40

35

35

45

40

50

50

40

Idler jet

45F9

50F8

50F9

55F8

70F6

45F9

50F9

45F8

pump bleed

50

60

55

40

closed

100

50

70

needle valve

175

150

200

200

200

225

225

225

float level

8.5/15

8.5/15

8.5/15

7/13.5

-3

-3

-3

7.5/14

(intended use) Lotus Elan
& Cortina
Alfa 1750 Maserati
3500 GT
Alfa Romeo
2600
? ? ? BMW
1800

     Conversion Kits

From Weber's own guides, the following table is a list of the standard jettings
      as supplied in their conversion kits. The kit #'s are also listed in the table.

Conversion
Kit
number
application Carburetor
and
qty.
Main
Venturi
Aux.
Venturi
Main
Jet
Emulsion
tube
Air
Corrector
Jet
Idle
Jet
Acc.
Pump
Jet
Pump
Ex.
Valve
K009 Sprite
Midget
950,1100cc
1 of
DCOE 40 2
32 4.5 140 F2 175 45F9 50 Closed
K011 Sprite
Midget
1275cc
1 of
DCOE 45 13
34 3.5 130 F2 175 50F9 50 50
K041 MGA 1 of
DCOE 45 13
34 3.5 145 F16 160 50F9 50 Closed
K043 MGB
1963-74
1 of
DCOE 45 9
36 4.5 150 F16 170 50F8 60 Closed
K044 MGB
1975-80
1 of
DCOE 45 13
34 3.4 145 F2 165 50F9 50 50
K124 Midget
Spitfire
1500cc
1 of
DCOE 40 18
28 4.5 125 F16 160 45F9 50 50
K125 Midget
Spitfire
1500cc
2 of
DCOE 40 18
30 4.5 115 F16 170 45F9 50 50
K126 Midget
Spitfire
1500cc
1 of
DCOE 45 13
34 3.5 150 F2 175 55F8 50 50
K131