All these jets!!(Weber Re-Jetting)

[73 gt man]

I am begging please help, when someone gets a chance I need those jet parameters,

humbly yours

Sean :o

[RallyBob]

Originally Posted by 73 gt man I am begging please help, when someone gets a chance I need those jet parameters, humbly yours Sean :o

You haven't given any parameters of your engine which would affect jetting. Is it completely stock? What you have there is typical standard jetting for an Opel, as delivered by Weber. The only thing that may change the jetting besides local issues (fuel for example) is the altitude. You will probably have to jet a touch leaner to compensate (as I recall about 3-4% per 1000 feet above sea level). So perhaps down to a 135 main jet would suffice (1.35 mm orifice vs. 1.40 mm, which is just under 4% smaller in diameter).

Other than that it's up to you to decide what needs to be done. Jetting can't be done by telephone or email, you have to run the engine and observe the characteristics of throttle response, power, economy and spark plug readings.

If you read some of the threads on jetting you'll see there's a bunch of advice pertaining to this, but there are not hard rules unfortunately, just guidelines. Every engine is a bit different....

Bob

[73 gt man]

Bob,

Thanks so much, my engine is stock and I will find the 135 for my main jet, it is running just a little rich, I appreciate your help on this, I will let everyone know how it goes.

Sean

[tekenaar]

Originally Posted by 73 gt man I need some input please I am finishing my carb rebuild and I need to reveiw the jets I am at 1000 feet in elevation and my jets are as follows Pri air 160 Sec air 170 both mains are 140 I am pulling the idles now but I have the california weber with the solenoid on the side with the pri idle as always I appreciate it, Dean your video was awesome thank you for the help, my carb is just like yours the money is on the way. Sean

Agree with Bob on 135 primary main. With the ICO solenoid in primary idle circuit, that is jetted at 60, IMS, and unfortunately can't be changed. You CAN, however, change that ICO solenoid assembly to a regular idle jet holder and then I would recommend a 50 idle jet for your altitude. BTW, what is your secondary idle jet? HTH

[GoinManta]

http://www.opelgt.com/forums/aftermarket-down-draft-carbs/6765-final-how-jet-weber-thread.html

Is a thread I did to compact all the Jetting questions in one thread.

Hope that helps.

Also as noted in this thread a while back:

Primary (32): Main 135; Air 150
Secondary (36): Main 150; Air 165

Is a good baseline for an Opel motor.

Charles

[tekenaar]

Originally Posted by GoinManta http://www.opelgt.com/forums/showthread.php?t=6765 Is a thread I did to compact all the Jetting questions in one thread. Hope that helps. Also as noted in this thread a while back: Primary (32): Main 135; Air 150 Secondary (36): Main 150; Air 165 Is a good baseline for an Opel motor. Charles

Have found best results by running closer to a ~85% Main/Air ratio . . . a little less (leaner, decrease pri main) at above-sea-level altitudes. Main/Air jetting pri 135/160, sec 140/160-165 works best for progressive 32/36 carb on stock/slightly modified 1.9 engines.

[73 gt man]

I appreciate everyones help I will change out the one jet to a 135, will the ICO match up to a regular idle jet holder, I was under the impression that it would not.

[tekenaar]

Originally Posted by 73 gt man I appreciate everyones help I will change out the one jet to a 135, will the ICO match up to a regular idle jet holder, I was under the impression that it would not.

Yes . . . I swapped one in reverse, regular to ICO, a couple of years ago as I wanted to cure a dieseling (run-on) problem on that particular engine. That carb is now on Ted's GT engine in San Antonio . . . with the ICO solenoid.

[EJprovost]

Originally Posted by tekenaar Have found best results by running closer to a ~85% Main/Air ratio . . . a little less (leaner, decrease pri main) at above-sea-level altitudes. Main/Air jetting pri 135/160, sec 140/160-165 works best for progressive 32/36 carb on stock/slightly modified 1.9 engines.

What adjustments would you make for an altitude of 4330 feet?

[GTJIM]

Originally Posted by EJprovost What adjustments would you make for an altitude of 4330 feet?

Dig a hole 4330 feet deep - or move down to the coast .........

Listen to Otto and Dave - altitude does have an effect on the carb mixture and can require slight leaning out of the idle circuit as you go higher.
Just remember if you lean out the carb then it will run lean if you do drive down to the coast ...

[tekenaar]

Originally Posted by EJprovost Originally Posted by tekenaar Have found best results by running closer to a ~85% Main/Air ratio . . . a little less (leaner, decrease pri main) at above-sea-level altitudes. Main/Air jetting pri 135/160, sec 140/160-165 works best for progressive 32/36 carb on stock/slightly modified 1.9 engines. What adjustments would you make for an altitude of 4330 feet?

Perhaps reduce primary main jet by 5 (130) and leave everything else the same. Progressive carb, remember . . . running smog test only uses primary barrel of this carb.

Then you might try 5 less on primary idle, but don't do that first! Primary idle/transition (idle jet) fuel volume depends on primary main jet, so changing main jet will also affect idle/transition mix, even without changing idle jet!

It's still a bit of "trial and error", Liz . . . very much specific engine condition dependent. Two of the "same spec" engines may have different jetting requirements to "tune" them to the same level.

Becomes somewhat "black magic" at this point, I'm afraid . . . much simpler with an AFR meter and wideband O2 sensor in the tail pipe. Saving up for one of these rascals to make my life easier.

[EJprovost]

I wish I could! We have such strict Emission laws here, I'm having a real struggle getting the carb thing adjusted right to pass the test. I have a DVEG 32/36 Weber on the 73 GT

[EJprovost]

Originally Posted by tekenaar Perhaps reduce primary main jet by 5 (130) and leave everything else the same. Progressive carb, remember . . . running smog test only uses primary barrel of carb. Then you might try 5 less on primary idle, but don't do that first! Primary idle/transition (idle jet) fuel volume depends on primary main jet, so changing main jet will also affect idle/transition mix, even without changing idle jet! It's still a bit of "trial and error", Liz . . . very much specific engine condition dependent. Two of the "same spec" engines may have different jetting requirements to "tune" them to the same level. Becomes somewhat "black magic" at this point . . . much simpler with an FA Ratio meter and wideband O2 sensor in the tail pipe. Saving up for one of these rascals to make my life easier.

All right! "Black magic" it will be then! Wish me luck!

[tekenaar]

Originally Posted by EJprovost I wish I could! We have such strick Emission laws here, I'm having a real struggle getting the carb thing adjusted right to pass the test. I have a DVEG 32/36 Weber on the 73 GT

So, did you wire up your DGEV electric choke to the same lead (black/yellow to right horn) of the original Solex? Is the E-choke properly adjusted for your area? This will also affect running mixture, especially if maladjusted.

[EJprovost]

I don't know, I didn't do all the altering, but that is definitely something that I will check out. Just barely had all the electrical fixed back to original from the steering column, and also put in the Otto Start, thankyou! Also looks like a 1.9 high compression Engine from, I'm guessing 1970 has been installed *19S-0678061*. The sticker on it expires the end of this month, I'm not sure of the alterations done on it in the past, so it would pass last year, but it wasn't anything original, was jimmy rigged of sorts! Engine does roar! definately rich on the gas.

[nobody]

Actually Otto that's a very good point. Of the multitude of Electrical goofs this cars horns were wired to be positive switching with a button under the dash. I fixed it to be normal again so good thinking. I've contacted Gabriele for jets and there is a rebuild kit there already. You can only imagine the wiring mess this lovely car had. Let's see incorrect dash, bad ignition switch, two key switches installed, horn, column wiring was a mess and lets not leave out the stereo on the passenger floorboard or the turn signal wiring. Geez if all it is is the choke connection I'll be doing a happy dance big time.

[ConreroGT]

Idle Jet for DCOE's

Does anyone have a list of the idle jets for the DCOE's in order of LEAN to RICH etc?

I suspect my idle jets ar too small and the book recommends to "increase" the jet size. My mixture screws have NO effect whatsoever on what I do to adjust.

So when it says to "increase the jet size" what is it refering to? I have f8-55 idle jets right now. I tried f7-65 (It got WAY worse) then tried f9-50 which cause the carbs to severly pop below 2500 rpm.

The f8-55 I have on now will mildly pop occasionally from the carbs but not too bad. The main issue is I can't fine tune the mixture screw.

Above 2500 rpm, everything seems fine. It pulls hard up and beyond 6k.

Current jetting:

CHOKE: 34
MAIN JET: 145
IDLE JET: 55F8
EMULSION: F2
AIR CORR.: 200
PUMP JET: 45

As I'm beginning to understand:

The f# is the size of the AIR hole on the side of the jet

AND

The 055# is the size of the hole for FUEL at the tip or end of the jet.

Is this correct?


Anyway, a list of jets in order would be helpful and or a recommendation (close-infield-ballpark-sorta guess on which way I need to go. I can see it getting ex$pe$ive to keep guessing and $32 a try if I'm not even on the field.

Thanks.

[nachi11744]

Hello,
I have no idea if this will help or just throw a spanner in the works, but this is the stock jetting for a Weber(UK)32/36DGV and DGA(E)V for the 20S engine to replace 35/40INAT and GM Varajet.
Manual choke kit #22680935
32/36 DGV
Pri Sec
Main 145 115
Air 155 110
E/tube F6 F6
Idle 45 50
pump 50 blank
Float level(no gasket)41mm

Auto choke(electric)kit #22680583
32/36 DGAV
Pri Sec
Main 130 120
Air 155 110
E/tube F6 F6
Idle 55 50
Pump 50 blank
Float level(no gasket)41mm

FWIW, I have had kit #22680583 on my Manta A's 20S for almost eleven years now and it runs a K&N open element aircleaner, so I run 140/125 main jets.I have a few other 'tricks' as well for 'tropical operation', namely a fuel cooler in the delivery line (cannibalized from carb engined Jaguar XJ6), it uses a/c low pressure(cold)line to cool the fuel when it would boil and vapor lock in traffic jams AND a vapor seperator with return line.
Yes, I have too much free time on my hands...............
Have a good week.

[asdasc]

THere is so much information on this thread, but it seems to be quite mixed between Weber 32/36 and Weber 38 DGAS.

So they tune the same? Do they use the same jets? Also, do you JB weld the same place to eliminate the enrichment tube? I just got my used 38 DGAS finally and need to order all the parts I need to rebuild it and rejet it. I will post pictures and more info in a short bit. I will be ordering everything from alfa1750 as he seems a great help!

[jordan]

The DGAS is much more difficult to tune as it is a syncronized double barrel carb instead of a progressive carburetor that really runs off of 2 separate barrels which are different sizes, the 38/38 has to be spot on to run well. I believe they use the same jets. I'm not sure about the 'power valve' circuit if that is modified the same way.

[tekenaar]

Originally Posted by jordan The DGAS is much more difficult to tune as it is a syncronized double barrel carb instead of a progressive carburetor that really runs off of 2 different sized barrels that are different sizes, the 38/38 has to be spot on to run well. I believe they use the same jets. I'm not sure about the 'power valve' circuit if that is modified the same way.

"The DGAS is much more difficult to tune as it is a syncronized double barrel carb instead of a progressive carburetor that really runs off of 2 separate barrels which are different sizes, the 38/38 has to be spot on to run well. I believe they use the same jets. I'm not sure about the 'power valve' circuit if that is modified the same way." (ahh the power of moderating )

Hmmmm . . . you don't say!

BTW, power valve is left unmodified.

[RallyBob]

They basically tune the same. The DGAS is more sensitive to the emulsion tubes being right/wrong in my opinion.

The DGAS also does not have the high speed enrichment issue the DGAV has...hence it is not a tuning issue.

The power valve ONLY needs to be modified if the cam is 'hot' enough to drop the manifold vacuum below the power valve's pre-set opening value. If you have a mild cam you can leave it alone. If you have a hot cam with low vacuum no amount of tuning will ever get the carb 'right' until the power valve opening value is changed.

I dealt with this myself for years and no one within the Weber 'circle' could give me an answer. I started doing a lot of research on Holleys instead, and applied their common knowledge to the Webers, and found huge success gaining driveability with the Webers on hot street driven Opels once the mods were made.

I found it ironic that while Webers were considered 'uber-tuneable', they really had no provisions for big cams and high compression mods in terms of pump-shot quantity, pump shot duration, and power valve tuning. Holleys on the other hand have TONS of tuning in these regards, yet the Holley metering blocks are 'fixed' while the Weber 'metering blocks' are fully tuneable (emulsion tubes, air correctors, idle jets).

Bob

[asdasc]

Thanks guys, I need to buy a selection of jets for tuning and wanted to see what I should get. It came with:

Idle 45 x 2
Main 142 x 2
Air Corrector 185 x 2
Emulsion F50 x 2

I will already plan the F66 e-tubes. I need a selection, as my car is going thru a transition. When I bolt this on, it will be a high compression (stock 1970) 1.9 with pertronics, a 2.0L head with stock valves and no porting, but it has a Isky Combo cam with Hydraulic lifters. It is getting a ported intake and a sprint exhaust. This is what I need to tune for.

Eventually, I will get my 2.0L build done and put it all on there. It will then have higher compression.

Thanks,

[Willy_g77]

Originally Posted by tekenaar With the jets you have available in both carbs, stick with the richer idles and here's what I'd go with for mains and airs in your engine: Primary (32): Main 135; Air 150 Secondary (36): Main 150; Air 165 You could go to a slightly richer mixture by using the 140 main and 150 air in the primary and the 150 main and 160 air in the secondary. I'm a little surprised that they sent you a 180 main to run with a 160 air for your secondary, as it is generally accepted Weber tuning practice that "airs" be at least the same size or larger than their "mains", at least from what I've heard and read about it. If you want to go with the 180 main in the secondary, definitely use the largest air (165) you have with it.

Well i finally tore down my rebuilt weber 32/36, i've tried tuning it and tuning it. i've found 4 jets. two down in the float bowl area and two beside the barrels. so the ones on top are air? and ones on bottom are the mains correct? so being in the mid west what would be good jets to put in?this is my problem.. if i dont have alot of pressure on the choke it will not run right. it will bog then rev. but if the choke butterfly's are good and tight it wont do that. but then that causes it harder to start.

[tekenaar]

Originally Posted by Willy_g77 Well i finally tore down my rebuilt weber 32/36, i've tired tuning it and tuning it. i've found 4 jets. two down in the float bowl area and two beside the barrels. so the ones on top are air? and ones on bottom are the mains correct? so being in the mid west what would be good jets to put in?this is my problem.. if i dont have alot of pressure on the choke it will not run right. it will bog then rev. but if the choke butterfly's are good and tight it wont do that. but then that causes it harder to start.

Surprised to find your query posted in this thread, as it's been discussed and answered here from every angle . . . many posts mine. Opeldean's prior #49 post in this thread answers your question.