Anyone running a weber progressive FAQ

[leeder]

While installing my new to me weber progressive carb on my 2.0 westy ive noticed that the runners dont fit into the carb, if the right side 2 are in the left 2 are left with a big gap. Is this like the air distribution box on the fi?i truly thought that both sides slid into the carb. The guy i bought it from had a 1.7 and lead me to beleive the 2.0 and the 1.7 utilized the same case. I bought urethane boots for this conversion and i just dont know if this is the correct application. bI didnt get any boots when i bought this setup. any help is much appreciated. the carb also looks a bit crooked sitting between the runners as well rob

[VDubTech]

You need the boots to attach the runners to the carb.

[leeder]

oh, so the runners dont go into the carb. The boots are clamped on. are there spacers between the head and the runners or just a gasket? thanks for the pic, very helpful Rob

[leeder]

how is it mounted to the case? ifigured i would fab something, do they come with a mounting plate?

[Wildthings]

Just use the thin metal gaskets between the head and the runners, you will need all the heat you can get. To steady the carburator against the pull of the accelerator cable, take a piece of light metal bar and go between one of the carb mounting bolts and one of the bolts on the case halves.

[NASkeet]

I would be very wary of using a single, progressive Weber carburettor conversion, on a 1972~83 VW 17/18/2000 Type 2 engine!

The three principal concerns are:

(1) Non-uniform fuel distribution between cylinders 1 & 3 versus 2 & 4, owing to the orientation and configuration of the carburettor mounting adapter, which does NOT properly mix the air and fuel, from the two carburettor barrels.

(2) Shallow air-filter housings, of just a few inches depth, cause considerable air-flow restriction.

(3) Carburettor and/or inlet manifold icing, owing to lack of inlet-manifold heating and/or inlet-air pre-heating, under cool, damp conditions.

There are numerous Internet links, dealing with carburettor icing, several of which illustrate a psychometric chart, showing under what temperature and humidity conditions, the occurrence of carburettor icing is most likely.

Poor fuel distribution and air-flow restrictions, give rise to poor fuel economy, together with the possibility of experiencing both over-rich and/or over-lean fuel mixtures, at the same time, in different cylinders, resulting in premature engine wear and localised overheating.

If one must use a single carburettor, then a mixing chamber is essential, together with some form of de-icing (e.g. electrically heated "hedgehog")and thermostatically controlled, inlet-air pre-heating! The best options are either twin carburettors or multi-point fuel injection.

Regards.

Nigel A. Skeet

[leeder]

Nigel,
Thanks for your input, I truly apreciate it. I have every intention of going back to my fuel injection set up however, until I can work out some kinks the summer is slipping by... Right now im looking for the boot that goes from my air distributor to the throttle body, no dice, cant find one. Sooo the reason im going with the weber is it seems like it would be a bit easier obtaining parts for so i can get on the road. Ive got some big plans rob

[VDubTech]

[leeder]

Nope its a seal(i think) that goes in between the the throttle body and the air distribution box. I think its like a gasket? I bought this camper incomplete and am trying to peice it together. Rob

were abouts in syracuse are you at? I have family in Manlius(sp). they own a carnival Wheelock rides

[Duncwarw]

Hi Nigel,

It's nice to finally see some HELPFUL information posted on this subject.

I like my Progressive and haven't really had much in the way of cold weather troubles. One day, I'll replace it with Del Ortos, but for now, I'm enjoying the ride.
_________________
“To find yourself, think for yourself”
Socrates, 470 BC - 399 BC

[GreenBrick]

[leeder]

thats the one! out of stock is the key part i noticed! I want to be able to drive this fine machine. know what i mean? Fall draweth near!

[flabay]

It looks like it's in stock to me. Try a PM to Scott. You will be so much happier if you get your stock injection going. The progressive kits are complete junk.
_________________
<<<R.I.P. 74' Euro Weekender
New Old Bus:
78' Champagne Edition Passenger AKA "The Turd"
Still can't figure out how to install this Charcoal Can right with my 40mm dual solex carbs. PM me please.
Click to view image

[Duncwarw]

Oboy....
_________________
“To find yourself, think for yourself”
Socrates, 470 BC - 399 BC

[leeder]

Part Number:
022 133 073 A
Throttle Valve gasket fits between the throttle valve housing (aka throttle body) and the intake air plenum. Genuine. Also interchanges with VW part number 025 133 073.

Details

Price: $ CAD 15.40 ($ USD 13.7


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Quantity Out of stock

[leeder]

without that gasket there is a huge gap. Im assuming it would be a monstrous vacuumn leak correct? Rob

[SixVolt]

I hope this is not considered a thread hijack. I've read all the old posts denigrating the progressive. Are there any positive comments about the progressive? How did one purportedly "bad" carb 'set up' come to so dominate the aftermarket for bays? Were mechanics that stupid about FI and duals that it was allowed to happen? Could it be that despite the current 'demonization' there was at least some rational reason for going to this set up? Understand, I do not have a 'dog in this fight'. I have stock FI in one bay and dual webers in the other, but even with the already documented shortcomings, why is the progressive so demonized?

Further, why weren't its shortcomings addressed? Heated manifold? More importantly, is there a viable single carb option for the type IV engine? I ask this in part because at the end of the excellent Jake Raby Type IV video rebuild, in an effort to show the engine running, they use a progressive. I understand that Jake was only trying to focus on the 'long block' issues and not necessarily address fuel delivery, but why do so many go to this option if it is so bad? I saw one "home improvement" method posted here earlier, but why hasn't Weber come up with heated manifold idea? Could the old EGR port on the old type IV mufflers be used to heat the manifold? I'm only asking to address the issues raised in use of the progressive, not to promote or denigrate any approach. Any suggestions?

[Petervw]

I changed to the progressive several years ago and I to have always wondered why the proggy gets so much of a bad wrap ...for sure there is a difference between low speed driving and fullout throttle causing a lean/rich situation which is hard to correct if at all possible and it would be desirable to have vacuum controlled secondarys like the more modern carbs, but if you stay within the limitations of its design, much like staying within the limitations of the type2 in driving habits etc., all should be fine. ..I know it takes a whole new learning curve(at least for me with plenty of frustrations) and desire to set them up correctly, and when so, they then work very well(that is not to say they are perfect)...on my own van the intake runners are insulated and the base does have heat coming up from the port on the cooling tin and a small K&N filter, the plugs look good...absolutely great to drive for a stock motor..it starts immediately, purrs like a kitten at 800RPM..pulls smoothly and no problem holding the 65MPH mark and the plugs look fine...at the moment I am looking for another center mount set up that has more adjustments built into it, like for high altitude driving etc. and vacuumed controlled secondaries...any suggestions for a 2 barrel.....

[NASkeet]

I have no quarrels with the Weber 36/32 progressive, twin-choke carburettor itself, which is a good, well-tried carburettor, used as a factory-fitted, stock installation, in many applications, including European Ford, Fiat, Alfa Romeo, etc.

My criticism, is solely with regard to the nature of its installation and adaptation, to the 1972~83 VW 17/18/2000 Type 2 & Vanagon.

The other potential problem that I forgot to mention, was the transplantation of the Weber 36/32 progressive, twin-choke carburettor, from one engine type to another, even if both engines share the same nominal cylinder displacement.

Factors such valve timing, volumetric efficiency and inlet-manifold vacuum characteristics, will be influential factors. It is likely that fuel jets and other components, will need to be changed, in order to obtain the correct air-fuel ratio, under all conditions of engine speed and load.

Insulating the inlet-manifold pipes, is unlikely to mitigate the icing problem and from what I know (I'm a British B.Sc. & M.Sc. graduate of Applied Physics & Applied Energy Engineering) of the physics of the icing mechanism, is more likely to exacerbate the problem, because heat from the warm engine-compartment environment, will be less readily conducted through the inlet-manifold pipes, to the evaporating fuel droplets. Hence, the vaporising fuel droplets, absorb heat from the surrounding warmer water vapour, in the manifold pipes, whose internal energy is radically decreased (but which cannot be replaced rapidly enough, through the manifold pipes, especially if they are insulated!) and hence turns into ice.

During the two winters, when I used my 1973 VW "1600" Type 2 Komb (at that time, still with the factory-fitted, AD-Series VW 1600 Type 1 style, twin-port engine), the single Minnow-Fish carburettor & inlet manifold, suffered terrible icing problems, despite the exhaust-gas heating of the inlet-manifold centre section and 90W electric de-icer element, in the entry to the carburettor.

The after-market, pancake air filter, atop the Minnow-Fish carburretor, lacked any provision for air preheating, so this made the problem even worse. I partly overcame this omission, by blanking off most of the air filter and rigging up a 2 inch, flexible cardboard hose, to the stock pre-heater duct, adjacent to engine cylinder No. 2.

Under similar weather conditions, I would anticipate icing problems, of similar or greater severity, with the single Weber 36/32 progressive, twin-choke carburettor, used in conjunction with the commonly available manifold adapter, for the 1972~83 VW 17/18/2000 Type 2 & Vanagon.

Regards.

Nigel A. Skeet

[Petervw]

I only have practical experience to offer (although not perfect) with the Type4 motor and what works for me here in Canada with many years of driving the van across this contintent with never once having any problem with my set-up..., (concerning the Type 1, I know nothing about its intake runners and iceing problems) ... By insulating the intake runners of the Type4 with an insulating wrap, heat will travel along the runner from the "head" thus speeding up the process of heating the intakes and drawing the heat up Further along the intakes to Nearly the carb and it keeps it that way...as stated earlier, I also have center base heat..2 sources..... thus no problem with fuel dropplets etc.....