Sterile Unmarked ChiCom Weber Copies

[FJCamper]

Distribution: To All Commands
Subject. Sterile (unmarked) Weber carburetor copies.

These devices have been traced by EBAY to Chinese Communist origin, but shipped from various CONUS (Continental United States) locations to purchasers, indicating the presence of sleeper agents.

Example: http://www.ebay.com/bhp/weber-idf

The photographed example is now in evaluation for function and performance against original Weber hardware. Characteristics of this example reveal even though it is sold as a 40 IDF, it has the same barrel diameter as the Weber 44 IDF and the externally marked Chinese copy HPMX as sold by EMPI. This allows the unmarked 40 IDF to accept larger venturis originally made and intended for the genuine Weber 44 IDF and HPMX.

Experts consulted on this assert that this feature suggests the sterile copy is related to the HPMX, and may in fact be unmarked HPMX's being sold as black market or gray-market devices.

Another opinion is by circumstance of being unmarked, these copies may be marked and resold as "Genuine Webers" by companies who have legally obtained the Weber name under license and sell the copies with no more than an adhesive label.

Original Weber production in Italy ended in the 1990's and production moved to Spain.

Some non-HPMX copies have been made stamped with FAJS, but this is not the circumstance with the sterile devices. An identifying feature of the sterile devices is the secondary venturi, always marked with size on even HPMX copies, is not marked, but believed to be 4.5 based on appearance.

If you are in possession of intelligence on these sterile devices, please forward it to this command. No classification marking is required.

FJC

[H2OSB]

But do they work? That's what *I* want to know.

H2OSB

[FJCamper]

Hi H2OSB,

Well, they look good. Nice finish, etc. We're setting them up with 36mm venturis for 7000 RPM service in our 1600 Historic Sportscar Racing Ghia.

The legal 356's run Solex 40PII's on 36mm vents. That's a carb I'd love to see somebody copy.

We won't be able to track test until February.

FJC

[Marc]

..it has the same barrel diameter as the Weber 44 IDF and the externally marked Chinese copy HPMX as sold by EMPI. This allows the unmarked 40 IDF to accept larger venturis originally made and intended for the genuine Weber 44 IDF and HPMX.

Interesting. I once grafted some 40IDF chokes into the 44s on my wife's bus to see if it'd be worth purchasing some legit smaller ones (it wasn't, so I went with smaller carbs). Built up the O.D. with duct tape - the metal-foil kind, not the cloth.

I suppose I could look it up, but while we're on the subject does anyone know if the 48IDF chokes interchange with the 44s?

[FJCamper]

Hi Marc,

I know the 48 IDA (not IDF) venturis do not fit a 44 IDF, as we have them both here.

I've never worked with an 48 IDF in any capacity.

FJC

[Marc]

I've never worked with an 48 IDF in any capacity...

I've got a set on the shelf that I haven't taken apart yet, just curious if they could be choked down using 44IDF vents without resorting to the duct tape Not much information available online, but aircooled.net sells 36mm chokes to replace the common 40mm in the 48IDF so I presume they're larger O.D. than the 44s' are.

40IDF chokes are 71506.xxx and 44IDFs' are 71507.xxx...no hits when I Google 71508


Of course the IDA is a completely different animal.

Are you still looking for some 36mm 44IDF chokes?

[FJCamper]

Hi Marc,

I've already located a set of 36mm 44 IDF vents. I needed them as extras so I could take at least a couple of sets of carbs to the track pre-setup.

My 44 IDF 38mm vents are for Daytona only, and I have spares enough to trade.

I have acquired and rebuilt a set of Italian Weber 40 IDF-78's, which came in pairs on Alfas and Fiats. Just 28mm vent good street carbs. I tried to make racing carbs out of them and hit too many $$ obstacles, such as the 3.5 secondary venturis all needing to be replaced with 4.5's.

I will be trading these off. They too take a 44 IDF venturi!

FJC

[Piledriver]

But do they work? That's what *I* want to know.

H2OSB

There was a thread a few months back on the ebay IDFs that should be enough to set your expectations to a realistic level.
At least you have reasonable recourse if its junk, and pay via Paypal for more security.

On the street, in a bug, they will suck to live with IF they work, in a Ghia, bus or 914 they are almost livable as you can get to the idle jets to clean them out on a regular basis. A T1 installation makes life hard unless you install at least through-inner-fender access plugs (1" electrical knockout plugs) or best, the available access doors.

I suspect if i were ever to run carbs again, (and didn't have Italian 4IDF/36s sitting in a box) I'd try Kadbombs due to their sheer simplicity/reliability.

Do the recent copies have the improved idle air setup? (ala Jet Doctors?)
Otherwise IDFs are effectively built so as to funnel anything that gets by the air cleaners into the idle jets.

[Marc]

IDFs are effectively built so as to funnel anything that gets by the air cleaners into the idle jets.

Couldn't have said it better Good filters, well-greased and carefully installed (even with prefilters) somehow still manage to let enough tiny particles through to cause the syndrome.


Clearing the idle air correction passages on non-Jet-Doctor-equipped IDFs isn't all that hard to do in a full-bodied Beetle, though - practice makes perfect, and you're afforded plenty of that
An air nozzle with a flexible hose (or even one with a piece of tubing that has a bend in it near the end) is well worth the few minutes it takes to cobble together...learn not to lose the O-rings when you remove the idle jets and it's a piece o'cake.

[Marc]

My 44 IDF 38mm vents are for Daytona only, and I have spares enough to trade...

??? do you have surplus 38s or not? I found a single-IDF manifold to try on my trike in place of the 34DMTR now on it, when I turn it from an 1849 to a 1955 (probably not until ~Feb) and may want to try some vents >36mm...

[Piledriver]

IDFs are effectively built so as to funnel anything that gets by the air cleaners into the idle jets.

Couldn't have said it better Good filters, well-greased and carefully installed (even with prefilters) somehow still manage to let enough tiny particles through to cause the syndrome.


Clearing the idle air correction passages on non-Jet-Doctor-equipped IDFs isn't all that hard to do in a full-bodied Beetle, though - practice makes perfect, and you're afforded plenty of that
An air nozzle with a flexible hose (or even one with a piece of tubing that has a bend in it near the end) is well worth the few minutes it takes to cobble together...learn not to lose the O-rings when you remove the idle jets and it's a piece o'cake.

Ease of access depends on the manifolds, largely.
With tall manifolds, tiny hands are useful for any pulling of idle jets or mix adjustment.
A 1" hole saw and 4 well placed holes/side help tremendously.
The commercially available windows look to make it almost too easy.

I will be pressing some brass tubing in place of the air correction holes if I ever use them again as carbs.
(may even break down and put a jet socket on them so idle air correct is easily tunable)

[FJCamper]

Hi Marc,

I have three spare 38mm vents for the 44 IDF, which I bought from AirCooled.Net.

I really don't need anything for them, and if you'll pm mean address, I'd be glad to mail them to you. Free up some room in my venturi case.

The ability of the 40-44's to suck dirt into the idle jets is incredible, but we've found a way to minimize that. Of course, I started with Jet Doctors, and they helped, but were not good enough. We were racing Chump at Daytona in our Superbug (125 mph on the banks) and the happenstance of airflow, etc., on the Bug just channels all the sand, tire rubber, and general grit directly into the carbs. I tried everything from no filters to air filters with greased cork top and bottom gaskets. We got plugged up either way.

One of our team mechanics got desperate and tied a shop rag around the jet stack extensions, which also happened to cover the Jet Doctors. Damn if it didn't work! We ran clean and fast -- right up to when Hawkeye hit the wall later.

I realized we were onto something with that rag trick, and cut a block of dense foam to fit down over the jet stacks and air holes that let dirt in below the carb's top plate.

If it's stupid but it work's it ain't stupid.

FJC

[Piledriver]

I was considering the little foam "gas" RC car air cleaners on the raised jet stack/jet extension, never got around to it.
There is little point arguing with "works."

Its unfortunate Amsoil stopped making their dry synthetic media air cleaners in the Weber air cleaner format.
The similar (media) K&N>AEM Dryflos seem to work pretty effectively.

I wonder if "turbo hats" and hose-clamp-sealed dry media air filters would work better?
Probably wouldn't be looked at too kindly for historic racing.

OTOH someone is apparently making dry media filters for Webers...
http://www.kartek.com/parts/r2c-pro-ser ... -tall.html

[Marc]

...I realized we were onto something with that rag trick, and cut a block of dense foam to fit down over the jet stacks and air holes that let dirt in below the carb's top plate....

I had thought about doing that with some spare chunks of fuel-cell foam, but it seemed to be too open-pored to offer much benefit - hadn't thought about finding some "tighter" foam that's fuel-resistant enough for the job. Now I'm inspired to put every little scrap of packing foam I come across into a jar of gasoline for a day or so to see if any of it survives!

I tried making replacement gas-can nozzle covers on my 3D printer, but all the filaments I've tried to date (PLA, PETG, and ABS) melt upon exposure to E-10 gasoline

[Piledriver]

...I realized we were onto something with that rag trick, and cut a block of dense foam to fit down over the jet stacks and air holes that let dirt in below the carb's top plate....

I had thought about doing that with some spare chunks of fuel-cell foam, but it seemed to be too open-pored to offer much benefit - hadn't thought about finding some "tighter" foam that's fuel-resistant enough for the job. Now I'm inspired to put every little scrap of packing foam I come across into a jar of gasoline for a day or so to see if any of it survives!

I tried making replacement gas-can nozzle covers on my 3D printer, but all the filaments I've tried to date (PLA, PETG, and ABS) melt upon exposure to E-10 gasoline

RC trucks run on from 100% methanol up to 70% nitromethane E85 probably wont faze them at all.
The filters are cheap, too. (usually polyurethane IIRC)

Looks like some folks use the athletic cling-wrap foam-ish "gauze" for RC filter outerwears, made from the same stuff.
You could probably just use a bit of that and a ziptie, its dirt cheap might want to test that.

I'd test it but don't have any carburettors in actual service at this time: Everything squirts, except my ancient RC-10 which is electric...

PS: They sell nitrous systems for RC cars now. Seriously.