45mm WEBER DCOE jet recommendations for 2 liter motor?

[tisalover]

Gents, I have a fresh 2 liter with 9:3:1 comp ratio, headers and 318i head with appx Schrick 289 cam grind in my BMW 1800 TISA. Current mains are 145, idle 50, and F2 air correction. Would anyone with a similar motor and 45 webers be so kind as to share ballpark/ideal jetting that they have used. sincerely, Peter

Please include air correction and emulsion tube data if appropriate. Thanks again.

[goatman]

What are the Suffix number of the carbs? Here is some info I have for a set I'm selling. These are also on a 2000 motor with a larger Dr. Schrick cam and Tisa manifolds. I believe the circled stuff in the first image is how they are setup. I could check the carbs themselves for you if needed. But it will be a while before I can do that.

Also have a Weber manual from Haynes that might help.

[Preyupy]

There are a lot of variables, but a good place to start:

45F9 idle jets

40 pump jets

34mm chokes (36 if you want a bit more top end HP, but with a cost in drivability in the lower rpm range)

3.5 Aux Ventruies

135 main jets

190 air correctors

F9 emulsion tube

175 needle and seats

50 inlet valve

The idle jets should be good, this might be a bit rich on the main circuit but rich is safer than lean. Once you get it up and running you will need to do some tuning.

[hanksjim1]

OT: curious why you went with the 1.8i head?....I just got a car with the same piston/head combo...just trying to understand what the advantage is over a properly prepped 121Ti head.

TIA for your input!

Please email me:

hanksj@hotmail.com

[c.d.iesel]

I know you said WEBER DCOE - but for a baseline

comparision, here are the specs for the original Ti

motor with duel 40 PHH carbs

[TobyB]

What Byron (preyupy) said.

That's safe, and you may find that going down one main and also down

a couple- or even 3-5- air correctors also works.

A wideband o2 meter makes fine- tuning these carbs soooooo much more

accurate. And they CAN be tuned quite accurately, if you're realistic

with the chokes.

t

[mike472]

Here is what I ran with almost the identical motor:

Jetting list:

Choke 34

Aux choke 5.0

Main jet 125

Air correct 180

Idle jet 50F8

Pump jet 40

Emulsion tube F9

Start jet 140

Needle jet 2.25

Discharge

Bottom bowl 45

Bleed