Single Weber 40 DCOE Jetting questions

[Spudenater]

Seems like there are alot of threads like this cropping up now, but with the restart of the site, just searching for things has been tricky. So, I have a (as of now) stock 3tc. In the future, I'd like to raise the compression and do some mild porting, but for now lets just talk stock. I pulled the below info from Hachiroku.net

32/36 DGEV on completely stock 3TC with approx 160-185k miles. Stock mechanical fuel pump and lines.
Primary Fuel Jet: 130
Primary Air Corrector: 165
Primary Idle Jet: 45
Secondary Fuel Jet: 125
Secondary Air Corrector: 150
Secondary Idle Jet: 50
Pump Jet: 50
Emulsion Tubes: F-50
Venturi: 3.5

Single 40mm Weber DCOE 151, on very healthy stock 2TC with 125k miles. Stock mechanical fuel pump and lines. Factory 4-2-1 header and downpipe with 2” crush bent exhaust.
Main Jet: Unknown, they are unstamped, but visually they appear larger then 150 jets, which is the largest I had on hand to compare them to.
Air Corrector: 170
Idle Jet: 50F9
Emulsion Tubes: F11
Choke Tubes: 30mm
Venturis: 4.5

Then I got these specs for the 40 DCOE 151 factory tuning.

Carb Model
40 DCOE 151
Part #
19550.174
Main Venturi
32
Aux Venturi
4.5
Main Jet
115
Em Tube
F11
Air Corr Jet
200
Idle Jet
45F9
Pump Jet
40
Pump Exh
50
Needle Valve
1.75
Choke Type
MANUAL

What do you guys think I need to change for a reliable stock daily driver? If I were to bump the compression ratio up and do some port & polish work, what else would I need to change? Any advice is appreciated, thank you.

[Spudenater]

Well, I guess I'll just get one of the Weber Jet Pacs and fiddle with it until I get it right. I just can't seem to find any good info. I'll try and post back here when I figure it out.

[bubbajohnson]

That's the jetting info I posted on hr.net and here. That single 40 set up listed will treat you well on a stockish motor. I've driven that car year round with just mild adjustments to fuel mixture and idle speed, temperature dependent. Having a big box of jets with 2-3 sizes up and down will help a lot. I'm sorry I don't know the main jet size, if I had been thinking I would've tried to measure the bore to get a better idea what size the jet is. The main thing really is just understanding what all the different jets and adjustment screws do, driving, evaluating and adjusting in small increments until you get where you want to be.
Also I do recommend upgrading the fuel pump, I ultimately decided the stock pump works ok with a single 40, but really starves for fuel above 5000rpms. Now that car is running a Holley pump and regulator, with return line and will spin to 6500-7000 handily. ( you wouldn't really want to spin stock internals more then that anyways.). Fuel mileage is about 17 city, 21-22 highway.
Hope this helps!

[Spudenater]

So it's been a while, but I've finally gotten that magical combination of time, money, and alternate transportation (my '80 wagon is my DD). In the mean time I also added a mildly shaved head and ARP hardware, and replaced my weeping head gasket. My problem is that I can't find a good accelerator cable bracket. What do people generally use for these things? I could just get some stuff from home depot and rig some shit together, but I'd really prefer a proper piece to some janky shade tree engineering.

[Spudenater]

So, I've got everything put together and running well. Here's how I have it set up presently. This is with a shaved head, mild port, stock valves/cam, and 4-1 headers with 2.5" crush bent exhaust (no cat).

Single 40 DCOE with stock pump/lines
Main Jets: 145
Air Correctors: 185
Idle Jet: 45F9
Emulsion Tubes: F11
Choke Tubes: 32mm
Venturis: 4.5

It yielded my 27.5 MPG on my last tank of Shell 89 octane with mixed driving (mind you on the freeway I cruise at 65mph), and seems to have pretty good response across the range. I don't know how it compares in giddyup to other single DCOE's, but it's better than my anemic Aisan A40 was for damn sure. It's jetted a little bit lean (tuned for MPG>HP), but still pulls well at pretty much any RPM. I might try a slightly larger idle jet (50) cause it's seems a little grumbly below 2k RPM, but overall I'm very happy with this set up as is, and I'm sure my wallet is too for once.

On a side note, my jet-pac came with two F7 emulsion tubes. I've read that the number of these tubes were assigned chronologically, so they have no correlation to their specification. That said, has anyone ever messed around with emulsion tubes? I feel like the effects would be damn near negligible.

[bubbajohnson]

http://www.s262612653.websitehome.co.uk ... webers.htm

There's a chart part way down this page showing which emulsion tubes are leaner and richer. My basic understanding is that they change where the main circuit kicks in more then anything. Sounds like you have that thing heading the right direction though! Maybe I ought to retune mine for mileage, 27 highway sounds nice.

[Spudenater]

Haha, yeah, I was pleasantly surprised. A light foot goes a long way I guess. I'm planning on taking a trip to the west coast this summer, and since I'll have no particular place to go and no particular time to get there, I might try and see how far I can stretch that mileage. I'm glad even though it's efficient, it's not a pansy. I had to merge into freeway traffic from a standing stop, and had my girlfriend and my roommate in the car. I really wound it up, and my roommate was like "Damn man, I can't believe this is the same motor!". Anyways, I'll take a look at that chart, thanks for the info!