weber 34 jeting advice

[64 200 ranchero]

i just bought my first of 3 weber 34's and need to know if someone can tell me what jets i should start with i know the stock jets will be too lean, right now i have a 69 jet in my autolite 1101 on the car, i know nothing about weber carbs

 

[64falconsix]

Webers are easy to tune and jets are easy to get,With the setup in my sig and 75 feet above sealevel, my air fuel ratio is 12.5 at low cruise and 13 at high cruise and WOT. all idle jets are .65 , center main is a 180 and end mains are 165. I have the center idle mixture screw out 2 1/2 turns and ends 1/2 turn. The end carb idle speed screws are turned in just far enough to keep the butterflies from sticking. Also make sure you use a pressure regulator, the webers will not handle more than about 3 1/2 or 4 psi. I run mine at 3 PSI but still have a fuel boil issue after running it that makes it hard to restart, the heat from the headers seems to be the issue,I will be trying a heat sheild and phenolic spacers to fix this issue, I think the stock weber jets are .52 idles and .130 mains, at eleveations above 2000' drop 1 jet size , depending on your cam timing, head work and altittude this seems to be close to what other are running, there are several online companies that sell the jets. I use weber carbs direct http://www.webercarbsdirect.com/ . also on their site is a blow up drawing of the ITC/ICH carbs so you can see where the jets are located.

 

[JackFish]

viewtopic.php?f=1&t=54798

There are two threads in the sticky that might help.

 

[64 200 ranchero]

im thinking ill start off with 175 in all 3 and 65 idle, my setup is not progressive, all three will work at the same time, would that work?

 

[JackFish]

Oops sorry, those threads are for the progressives.
Hoping someone else will chime in with some help for your setup.

 

[vssman]

I think 65s are going to be too much if you're going to idle on all 3. When I was tuning my tri-weber, I also started out with idling on all 3 but couldn't get it to run good as it would stumble mid throttle. I think I had something like 45s or 50s for idle jets at the time. I went back to center carb idle only - fuel consumption went down a lot too... I eventually installed an AEM UEGO wideband O2 to help dial in the jets. What I thought was OK before I had the O2 was not - I was quite lean - like 17 at WOT. I don't recall the exact jet sizes I run now but they are around 190ish and I have different air jets too to have the mains come in sooner. Without the 02 sensor, I'd still be futzing around with the carbs or would have pulled the tri setup.

 

[64 200 ranchero]

i bought a 180 main and a .065, is it ok to run this carb by its self for a while till i get the other two or would it be too lean, i think ill get a wideband o2 to help

 

[64falconsix]

Should be able to tune for low speed and cruise, the weber is rated at 150 cfm, the stock 200 carb averaged 185 cfm, with the lack of end carbs the vacuume signal will change a little so 180 may be a little rich. an AFR meter will definatley help.

 

[64 200 ranchero]

i tried bolting the carb on today and it wouldn't fit, the mounting holes on the carb are not wide enough, im going to grind the holes a little to get it to fit, did you all have to do that too?

 

[vssman]

Yup. Rat tail file, dremel, etc...

 

[64 200 ranchero]

I installed it and it was running too rich, I think ill get a leaner jet to run it on for now, what would be a good jet to just run till I can afford to get the other 2

 

[xctasy]

Weber 34ICH - aftermarket fitment 1980s - date

This carburetor became very popular in the 1980s when the supply of Solex parts dried up, and when the only source for Zeniths was the Land Rover dealer network. They were sold as a cheap replacement which also improved fuel economy. This is true up to a point, and the 34ICH is still available today at around £80, but it is not as popular as it once was. Reasons? Firstly, the fuel economy improvement is achieved through two things - firstly the carb is a bit small for the application, with restricted gas flow, and secondly it is jetted to run fairly lean. Taken together these two factors certainly improve economy, but really hurt performance. The Weber is also very prone to jet blockages (worse than the Solex) and, more seriously, internal fuel passage blockages that can be almost impossible to clear. It can also suffer badly from carb icing - it really needs a heated air intake which the Land Rover does not have. If your vehicle starts easily on cold mornings, but splutters to a halt after a couple of minutes, then restarts and runs as sweetly as before, carb icing is probably the cause. Oddly, not all Weber-equipped Land Rovers suffer from this problem - it varies from vehicle to vehicle, for no apparent reason

My notes are that there are ICT and ICH's, and 27 and 29 mm venturi versions. It was used from 1966 to 1987, and is found in two version, the 27 is 1.063" and the 29 is 1.142". Each are far too small for more than the hp of a 2286 cc I4 that Land Rover used, the biggest engine from as small as 1159 cc. Its just a small European or English replacement carb for the old tiny 1-bbl Audis, Vauxhall, Bedfords, Land Rovers, early Rovers, Peugeots and, although unlisted, some Dak Daks, um, Volkswagens. There are 23 listings for the carb, aside from US listings for the dual and triple Pierce and Redline listings for some cars, plus the Falcon six tri power, VW and the same European cars that shared it in the US market.

MAKE MODEL YEAR CARB MODEL CHOKE KIT NO.
AUDI AUDI 80 1297cc 72-78 WEBER CONV. 34 ICH M W288
AUDI AUDI 80 1272cc 78-79 WEBER CONV. 34 ICH M W288
AUDI AUDI 80 1471cc 74-75 WEBER CONV. 34 ICH M W288
AUDI AUDI 80 1588cc 75-79 WEBER CONV. 34 ICH M W288
BEDFORD CA VAN 1500cc 63 WEBER 34 ICT M W292
BEDFORD CF VAN 1.6 - 1.8 - 2.0 76 WEBER 34 ICT M W292
DACIA 1397cc 84-87 WEBER CONV. 34 ICH W288
PEUGEOT 404 1618cc 70-75 WEBER CONV. 34 ICH M W287
PEUGEOT 504L 1796cc 73-82 WEBER CONV. 34 ICH M W287
VAUXHALL VICTOR 1599cc FD 67-71 WEBER CONV. 34 ICH M W288
VAUXHALL VICTOR 1759cc FE 72-75 WEBER CONV. 34 ICH M W288
VAUXHALL VIVA 1159cc HB 66-70 WEBER CONV. 34 ICH M W288
VAUXHALL VIVA 1159cc HC 70-71 WEBER CONV. 34 ICH M W288
VAUXHALL VIVA 1256cc HC 71-73 WEBER CONV. 34 ICH M W288
VAUXHALL VIVA 1599cc HB 68-70 WEBER CONV. 34 ICH M W288
VAUXHALL VIVA 1599cc HC 70-73 WEBER CONV. 34 ICH M W288
VAUXHALL VIVA 1759cc HC 72-74 WEBER CONV. 34 ICH M W288
VAUXHALL ASTRA BELMONT 1196cc 79-84 WEBER CONV. 34 ICH M W288
VAUXHALL ASTRA BELMONT 1297cc 79-87 WEBER CONV. 34 ICH M W288
VAUXHALL VAN HAV - CF 1800 cc 82 WEBER 34 ICT M W292
LAND ROVER 2286cc SERIES IIA & III WEBER CONV. 34 ICH M W292
LAND ROVER 2286cc SERIES II & III + SOL WEBER CONV. 34 ICH M W292
LAND ROVER 2286cc SERIES II & III LHD WEBER CONV. 34 ICH M W292

Even though the carb on its own is too small for a 3.3, you can jet it up to 2286 cc four cylinder Land Rover spec. So as long as its got the 29 mm chokes, it should do fine as a single carb, and there are specs to copy somewhere. Compared to the 3.3/200 Ford, the Bedford Van with slant 1975 cc and the Land Rover 2286 cc are best starts, the Bedford engine is a screamer, with similar power net as the early stock 3.3 engines, which were about 82 hp net and about 150 lb-ft. The 'Landy' in 8:1 was just 70 hp@4000 RPM and 120 lbft @2000 RPM, but just a 2.5 liter LR cam, 9:1 compression and the 53 to 60's Chevy Rochester Mon Jet B series carb makes that 85 hp. Even the 1600cc Bedford got 80bhp and 96ft/lb of torque, and the 1975 cc units were up to 98 to 104 hp and 112 lb-ft, high reving workhorses, with good peak hp, with a little less torque than a 3.3, so I'd use there settings. A good first start!

I'll find the numbers in a moment.

 

[xctasy]

Found it. Are your carbs ICT's or ICH's?

http://www.thesamba.com/vw/forum/viewtopic.php?t=396440

The 34 ICT was developed for single use on a Bedford CF van over here in the UK, and all the carbs supplied are jetted for this, not for a VW.
The jets as supplied are;
idle jet 52
main jet 130
air corrector jet 160
emulsion tube F78
needle valve 175

and confirmation, of sorts, is that the 34 ICT is the 1759 cc engine carb jetting, which was about 90 to 92 hp, good for a 200 tootling.Bare in mind this is a Dak Dak, um, VWforum, so its based on what a twin carb 1700 to 2000 cc Dak Dak, um, air cooled flat four VW engine needs.

http://www.volkszone.com/VZi/showthread.php?t=555376

The ICT is a carb for single use with a Bedford 1800cc engine. Which is why they don't work out of the box. The mains are wrong, airs are wrong, emulsions are wrong, idles are wrong and needle jets are wrong. I have no idea why the people who supply them don't insist on the jetting being at least ball park.

Multiply the 29 mm venturi by 5 and add a bit. Takes the main to 150. Add 20 to get the air at 170. (With a bigger capacity, you can take the main and air up incrementally)
I have 2 litres running on 165/185
Idles are usually best at 55.

Needles are 175 on the ICT as supplied. A clue can be taken from the type3 solex and type 4 which have 120 needle jets. That makes the carbs far less liable to get problems with fuel pressure. The bigger the needle jet, the more chance of the fuel pressure pushing the float down.

Emulsions are totally wrong too. F3 and F6 are used regularly by formula vee racers in Ireland. Less stumble off tickover less flooding under pressure.

What would help would be a rolling road tuner, to have a box of jets of all sorts and to set an engine up of each size. Then, people could ask the manufacturers to supply carb kits that work, with linkages that line up with the throttle tube and open the carbs together... But then, I'm certainly pissing in the wind now!

and for the little 2286 cc Landy,

http://forum.landrovernet.com/showthrea ... nning-Rich

Re: Weber 34ICH Idle Running Rich
I talked to the local Series Landy expert and he also agreed that the 'mixture' screw should do something. I have rebuilt the carb and this is the initial run on it. My wife is leaving for the UK on Wedensday, and after working on the car all day Saturday I am on a spouse-imposed work stoppage . I'll be able to pull the carb off Wed night after the kids go to bed and take a look at it. I suspect if the screw isn't doing anything, it may have something in there.

As far as the jets, I am thinking about trying a .170 or .165, I believe the .165 was what came with it (when fitted on a Rover). When I rebuilt mine it already had a .175 in it and the rebuild kit came with the same, although I ordered the rebuild kit from a carb shop, not a Rover shop.

Again, please send all ideas, and when I finally do get this un-screwed, I'll post the completion. Also, my sincere thanks for all of the feedback.

At least its running and driveable! During my trip to work today nothing fell off fingers crossed.

Cheers,

Scott

From http://www.expeditionlandrover.info/lan ... _carbs.htm

The stock Land Rover jetting for the 138 cfm at 1.5"Hg Weber 34 ICH is

The common Weber 34-ICH is a generic replacement carb and often comes under jetted for the Land Rover engine. If you fit one take it to a shop that can check air fuel ratios for you to make sure the jetting is OK for your engine. If you notice a real increase in fuel mileage it could be because the carb is running too lean and if you put long miles on the truck you can suffer a hole in the piston or burnt valves.

Stock jetting for 2.25 liter/2286 cc
http://siteground237.com/~gunsandr/show ... d683322a54

Weber 34ICH

The Weber 34ICH is a generic carburetor designed to be closely adaptable to individual engines. This means that the jetting is complicated enough to require an expert to get it tuned as close as possible to your engine's needs. However a 165 Main Jet , 190 Air Correction Jet and F6 Emulsion Tube will normally get a stock 2-1/4L engine running acceptably well at or near sea level. At around 7000 feet try a 155 main jet. Webers tend to be sensitive to altitude changes and need to be leaned out at around 5000 feet for proper running.
While the 34 ICH has more top end power than the Zenith it is the most susceptible to dirt and water in the fuel and can frequently cause problems if the fuel is not clean and well filtered. The Weber's main jet is located at the bottom of the float bowl, where it can be clogged with gunk. The Zenith and Rochester have their main jets supported from above, and are less susceptible to clogging and moisture.
When customers ask about the 34ICH we normally recommend the Rochester BV. The top end performance of the 34ICH is less than the Rochester, it is harder to jet and more often a source of running problems. However it can be an efficient good performing carburetor if properly jetted for your driving conditions and your fuel is kept very clean and free of moisture.

So I'd use the 34 ICT jetting for the 1759 or 1975 cc Vauxhall/Bedford 90 to 104 hp net slant 4 OHC engine, or the jetting for the 34 ICH 2286 cc Landy as a start, and drop fuel pump pressure to 2.5 to 3.5 psi by regulator.

 

[64 200 ranchero]

I changed the idle jet to a 52, it helped alot

 

[xctasy]

I changed the idle jet to a 52, it helped alot

Be very carefull you don't have a 25 or 27 mm venturi as opposed to the 29 mm. The carbs are stamped with the chocke size, and its important you don't have someting like a 32 ICT when you should have a 34 ICT or 34ICH.

Some are stamped 29 but are actually 27 mm, so measure the venturis or the recomended jetting below will be wrong.

Could you tell me if you have ICT's

or ICH's, and

what the stock jetting was before you changed the idle jet
idle jet before 52, what was it
main jet ??? 130 to 165 common
air corrector jet ??? 160 to 190 common
emulsion tube ??? F78 and F6 common
needle valve ??? 175

34 ICT, a carb without choke, about 150 cfm at 1/5"Hg, and 212 cfm at 3.0"Hg, with 29 mm venturis, was developed for single use on a or Bedford CF van/Vauxhall Victor, in 1594, 1759 or 1975 cc engines in the 80/83, 90/92 or 98/104 hp engines had std jetting for 1759 cc.
The jets as supplied are;
idle jet 52
main jet 130
air corrector jet 160
emulsion tube F78 orF6
needle valve 175

1.141 inch venturi with a 1.0236 sq in venturi area

34 ICH, a carb with choke138 cfm at 1.5"hg, 195 cfm at 3.0"Hg, 29 mm venturi, was most often a Land Rover 2286 cc/21/4 liter carb replacement, 70 hp.
The jets as supplied are;
idle jet 47 or 50
main jet 165
air corrector jet 190
emulsion tube F6
needle valve 175


Those will always get you in ball park with a single.

 

[xctasy]

These are the stock calibrations. Beware, there are 25 mm choke 34 ICH. It won't flow enough air


1 Carb 2 Part No 3 Main Venturi 4 Auxiliary Venturi 5 Main Jet 6 Emulsion Tube 7 Air Corrector 8 Idle Jet 9 Acceleration pump Jet 10 Acceleration pump bypass 11 Needle Valve 12 Float Level Measument 1/Measurement 2 13.Source

34 ICH 15290.020 25 4.50 130 F6 150 57 50 40 1.75 6.5 / 13 Special Applications

34 ICH 15290.027 29 3.50 165 F6 190 50 55 40 1.75 6.5 / 13
34 ICT 15290.035 29 4.50 130 F78 160 52 50 40 1.75 6.5 / 13 Redline Inc. Conversion

Incidently, converted to microns, your stock 1101 Autolite with 69 jet would be a 175 jet if a metricated Weber. Use the under lined, and jet up to 175 as a great start.

 

[64 200 ranchero]

I am running an ict, it is working very well now that I installed the 52 idle jet thanks for the help :mrgreen:

 

[Bob]

I need some advice. I inherited a 63 Falcon Futura with 200 cid, with Offenhauser 3 port intake manifold. Has 3 Weber 34ICH carbs. When I cleaned up the carbs, I noticed something peculiar. All three had 155 main jets, but one had a 55 pump exhaust valve (PEV), one had a 50 PEV and the third had a 40 PEV. I would like to set it up with center carb as main, then the two outer would be progreessive. What do you recommend the mains, and PEV's should be for them and also what is the procedure for synchronizing them in a progressive manner?