Weber jetting, what I've used that works

[bubbajohnson]

So I thought I would write up something to help those who are having trouble with their weber carbs and getting them dialed in. One of my biggest gripes through the last few years has been that although all the directions you will find say to look at and write down what jets are in your carbs, NO ONE seems to do this, or share the results. So here is what I’ve had in multiple Weber carbs, on multiple cars, with often vastly different engine set ups. These are all working setups, which were used on street driven cars, all adjustment screws were at or very near weber base settings. These are good functioning settings, which may not work perfectly for you, but can serve as a baseline. YOU still have to do the tuning and checking to make sure your car is in good running order, drive it, read the spark plugs, etc and decide if your carb tune is correct.

#1 32/36 DGEV on internally stock 3TC with approx 230-255k. Stock mechanical fuel pump/lines. Using a Offenhauser dual-port intake, pacesetter 4-1 header and 2.5 inch exhaust with high flow cat.
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

#2 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

#3 32/36 DGEV on rebuilt/fresh 2.0L 3TC with fairly large cam, oversized valves, mild port and polished head and high comp 89mm pistons, 4-1 Header with 2.5” exhaust. 3/8 fuel supply and return lines with carter fuel pump and pressure regulator. This engine was dyno tested at 115hp and 112 ft/lbs of torque with a slightly different tune, that showed as being a little lean, so it was re-tuned richer, but not re-dyno’d.
Primary Fuel Jet: 150
Primary Air Corrector: 160
Primary Idle Jet: 70
Secondary Fuel Jet: 145
Secondary Air Corrector: 155
Secondary Idle Jet: 55
Pump Jet: 50
Emulsion Tubes: F-50
Venturi: 3.5

#4 32/36 DGV on 3TC with stock bottom end, oversized valves, an aggressive cam and 4-1 header with 2.5” crush bent exhaust. Stock mechanical fuel pump and lines.
Primary Fuel Jet: 140
Primary Air Corrector: 150
Primary Idle Jet: 55
Secondary Fuel Jet: 150
Secondary Air Corrector: 155
Secondary Idle Jet: 50
Pump Jet: 50
Emulsion Tubes: F-50
Venturi: 3.5

#5 32/36 Weber on very healthy stock 2TC with only 120k miles. Stock Mechanical fuel pump and lines. Factory 4-2-1 header and downpipe with 2” crush bent exhaust.
Primary Fuel Jet: 125
Primary Air Corrector: 145
Primary Idle Jet: 50
Secondary Fuel Jet: 130
Secondary Air Corrector: 150
Secondary Idle Jet: 45
Pump Jet: 50
Emulsion Tubes: F-50
Venturi: 3.5

#6 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

#7 Dual 40mm Weber DCOE 151, on rebuilt/fresh 2.0L 3TC with fairly large cam, oversized valves, mildly port and polished head and high comp 89mm pistons, 4-1 Header with 2.5” exhaust. 3/8 fuel supply and return lines with carter fuel pump and pressure regulator.
Main Jets: 145
Air Correctors: 190
Idle Jets: 55 F9
Emulsion Tubes: F2
Choke Tubes: 36mm
Venturis: 4.5

This is an update to entry #7 on my list.
Thanks to a wideband O2 sensor, discovering my fuel pump was not putting out consistent volume, a float adjustment and a whole lot of drive time, fiddling and tuning I think I have the dual 40's tuned as well as I can with what I know about tuning DCOE's.
Its now running:
Main Jets: 140
Air Correctors: 200
Idle Jets: 60F9
Emulsion Tubes: F2
Choke Tubes: 36mm
Venturis: 4.5
This set up runs GREAT!! Most of the problem with the old "tune" was my fuel issues both with the pump not holding steady because of a slightly loose wire, and I discovered one of my carbs float level was different from the other and they both were set way to high, causing an intermittent bogging issue. Now that both those issues are sorted out and I've logged a good 700+ miles just watching the air/fuel meter and observing then adjusting jets, I'm very happy! The car feels more powerful and responsive then it has at any point with these carbs, I have no random bogging and can drive like as much of a jackass as I want to :cheers:. Just last weekend me and 3 friends loaded up the car with ourselves and maybe 200lbs of gear and took a 240mile trip to the mountains and back. I had no problem holding 70+ up any grade, only shifting to 4th gear every now and again and we got over 20mpg on the trip!! My air/fuel mixture reads about 14-14.5 at idle, so maybe a touch lean, but not bad. 13-13.5:1 at 60-70mph in 5th gear while cruising (Not uphill!). 12-12.5:1 with mild load and on most up hill grades in 4th or 5th gears and 11.5-12:1 under heavy throttle/5000+ rpms right up until it hits my rev limiter at 7000rpm.

[bubbajohnson]

Hi all, glad there's a 3tc forum again! Here's my weber jetting info from the old boards, hope it helps some folks .

[BOBLOOK]

Thanks for posting i copie and add the post in DIY section Thanks

[Mazota TE51]

Thanks a lot bubbajohnson I needed this for a guide.

[bubbajohnson]

You're welcome guys! Feel free to sticky the post, or add it other places, its all here to share .

[admayen]

Great information! I'm sure it will come in handy to myself or someone else. Thank you!

[thermos]

This is a great reference, have you done any baseline tunes for the 38?

[corolllin]

cool, when I rebuild my 32/36. I know where to go now!

[bubbajohnson]

This is a great reference, have you done any baseline tunes for the 38?

No, I've never used a 38/38. When I got tired of my 32/36's I just decided to go big or go home and get the DCOE's! In my wagon with the 2L motor, I only ever got 18-19mpgs in the city, 24-26 highway with the 32/36 and reality is it was under carberated in the top end. The dual sidedrafts suck fuel in city driving, we're talking 13-15mpgs, however they still get 20-22 on the highway if I keep the stupid foot out of it as much as I can!

I've been told someone good at what they are doing can coax as much power from a 38/38 as a single sidedraft and save some mpgs. I never tried that on my liftback since the single sidedraft setup popped up at a good price.

[thermos]

Thanks for the heads up Bubba. I'll post specs once I've got it dialed in. I scored this guy for 200 bucks NIB so I decided to jump on it! Nice work on the dcoe's though!