135$ Brand new IDF 40 Weber knockofs on ebay

[lcvaldetaro]

I have two Decade IDF 40's on my ghia. One of them went bad and need replacement.

Apparently decade is out of business. Their IDF40's had a larger tank, so I don't want to replace it with one that has a regular size.

I was fully expecting to pay something like 300$ each for an empi, but while looking at ebay, I found this:

http://www.ebay.com/itm/New-40-IDF-WEBB ... O0&vxp=mtr

Anybody ever tried?

I figure for the price it is worth a try and I bought 2.

The second question is the jets on them are:

"Venturi 28mm , Venturi (choke tube) 10.5mm, Main jet size 115 , AIR CORRECTOR JET size 200 , TUBE F11"

Is this the corrects jetting for a dual carburator application?

[jbbugs]

You get what you pay for.
Buy a Real Weber.

[lcvaldetaro]

Thank you. I'm willing to experiment. I used knockoffs in Brazil with great results. I still own one of them, but don't want to use it (Has nostalgia value - I use it to decorate my office - the only part left from my Super V). When I lived there imports were out of the question. The decades I used were great. Unfortunately while trying to clean it it got damaged accidentally. Shame they went OOB.

If the experience fails, I lost 270 bucks and time, no big deal. If it works, I found a good source for webers IDF40's....I'm willing to try, or TOFFT. I'll report back.

The most important question though, are those jets correct? This is a 1.9L Ghia , 9.5:1 comp ratio, with a hot cam (made in brazil - salvaged from spare parts for my super vee) - actually very hot cam - based on an isky 1010, but a tad hotter, 1:25 lifters, 41mm intake valves, puma dry-sump kit (again, salvaged from spares of my brazilian made super vee).

[Bruce2]

"Venturi 28mm , Venturi (choke tube) 10.5mm, Main jet size 115 , AIR CORRECTOR JET size 200 , TUBE F11"

Is this the corrects jetting for a dual carburator application?

Ask them what the idle jets are. Should be a 50. The other jets they list are what will work for a dual carb Beetle application.

[lcvaldetaro]

Thank you!

[lcvaldetaro]

First part of the report.

Carbs arrived. I looked them all over, look perfect.

1 problem - vendor by mistake shipped IDF44's. Since my manifold is 44, I think I will give it a try with the 44's, they should be better at high RPM. By hot cam will like it. Vendor charges the same for the 40's or 44s. I let them know, though.

BTW< the jets on this one are: Main 135, Air 200 Emulsion F11, Idle 55, Dif 36

Will post updates when I have them. Will probably install them this weekend.

[SC3283]

updates?

do any jetting...stock weber jets fit?

[Piledriver]

That's dead std dual 44IDF/36 jetting, assuming they are sized as marked...
If one was possessed to run a single (bad idea for several reasons) you would want F7 emulsions for starters.

Curious mostly for use as cheap and EZ-fit ITBs, but heck, maybe they actually work.

[Marc]

I suspect 135 mains may be a bit small; personally I'd go with ~150 for starters.

Idle jets also affect the progression circuit which is in use during most "normal" driving. If you find that you need to have the idle mixture screws open more than ~1 turn for a stable idle, that indicates that a larger idle jet is needed - but 55s are typical for 44IDFs and should work.

Here's John Connolly's primer on jetting/adjustments:
http://www.aircooled.net/vw-carburetors-jetting-102/

[GoMopar440]

That carb in the OP's link has been out of stock for a while now. I had been watching it since this thread was started. I still had the carb on my Ebay watch list so I tried using the "View similar items" button and found a few similar ones. Most were all about the same price, but the shipping was ranging between $40-50 on them making most of them no where as good a deal as the original listing. When I saw this thread come back to the top of the forum again today I went back to Ebay and clicked the "View similar listings" button again to see if anything new came up. I found a lot of the same, but there was another new auction for a 40 IDF clone listed there now. It has a BIN price of $89.10 and shipping is a slightly more reasonable $35.50. I bit and got one. When I went to check out through Paypal, the seller had deducted $3.00 for it being an order over $80, leaving me with a total of $121.60 to my door. I'm willing to take a chance on it for that price. i just bought it tonight (1AM), so I'll report back here with the jetting it comes with when I get it in the mail. The automated auction response says I should receive it by Saturday March 5th.

BTW, Right now the new auction listing says there are more than 10 available, but it looks like it's only a 24 hour sale auction, with just a little over 20 hours left to go.

EDIT: Oops. I guess I should post the link to the new auction...
http://www.ebay.com/itm/151894855573?_t ... EBIDX%3AIT

[Marc]

...I bit and got one...

Is it your intention to run a single 44IDF?

[GoMopar440]

Not a single 44 IDF, but a single 40 IDF. I plan on keeping my 1600 DP engine fairly close to stock (internally), at least for a while. The original plan for my rail engine was to mod a pair of 34PICT-3's and make a very cheap, and hopefully efficent, set of duals. But at the price I found the carb mentioned above, it was too good a deal to pass up.

This is the intake I want to run it on. http://vwparts.aircooled.net/Deluxe-Cen ... 04.315.htm

[Piledriver]

If you really want a single, that's the manifold you really must have.

You can run dual 40s, even on a stockish motor.
Given the price of these carbs/ manifolds/linkage etc, the cost would be little more, esp if you rolled your own linkage.

[Marc]

40IDF, gotcha. This thread has taken a few twists & turns, just wanted to see where we're at now. Did you miss Pile's post warning against using a single?
The problem with having the carb so far away from the heads is that the mixture doesn't stay in suspension - when the throttle's opened and vacuum drops, fuel condenses on the manifold walls resulting in a lean condition that even a toilet-flush accelerator pump won't cover. The larger the runner cross-section (lower flow velocity at a given RPM) the worse it gets, and most aftermarket manifolds are sized for full-throttle power, i.e. too big for the street.
Manifold heat is the only cure, and most manifolds for aftermarket carburetion have only rudimentary heat riser plumbing. The "deluxe" IDF manifold that aircooled.net sells is a big improvement IF you have sufficient exhaust flow through it.

There's the rub, unless you're running a stock muffler (and who would, with a carb this big?) there's no net pressure differential across the heatriser pipe, so "flow" isn't really present, merely convection heat transfer.

People have tried plumbing one end of the heatriser to a low-pressure point in the exhaust (such as the collector in a 4-into-1 system) with mixed results.

Presently I have a 34mm 2-bbl on my trike with NO manifold heat. Last summer it was no problem, but for the last few months I've needed to let the engine warm up for about 15 minutes before it could get out of the driveway without flaming the clutch - and even then the flat spot on acceleration is bad enough that it's a safety concern.

Even with ample preheat, a single IDF will need substantially richer jetting than would duals. Jets aren't prohibitively expensive (although if you need to pay for shipping every time you buy a set to try it can add up fast) but many folks have found it necessary to go to a slimmer emulsion tube (more fuel in the well => richer on acceleration) such as the F7. In F11s, figure on starting with 160 to 170 airs, 145 to 160 mains, and 65 idles (sea-level). The accelerator pump discharge bypass valve needs to be shut off completely to maximize the pump shot (they make a "zero" bypass jet for that purpose, or you can solder it up).

I strongly recommend going back to your original plan unless you only intend to drive only on warm sunny days.

...or buy a second carb, etc. and run duals as Pile suggested. Those could be transplanted to a bigger engine down the road, too.

[GoMopar440]

Honestly this is the first time I've heard anyone say a properly setup single center mounted carb system can't work well. Everything I've read to date says it will never be as good as a dual carb setup if you don't use carb heat with a single (1 or 2 bbl) carb. However with a properly working carb heat setup, and everything else in good working order, I should be able to get similar performance between the two different types of induction setups. That is under the assumption that the venturies and jets are sized properly for the engine they are mounted on and the engine is in good mechanical order. I'm always open to learning more about what has been proven to works and what doesn't, so please let me know if there is something I'm missing here.

The ACN deluxe manifold I linked to above has heat risers that reach all the way up to the base of the carb mounting flange. Not just to the bottom of the intake pipe. In the cut away pic of that manifold you can see that there is a threaded bung cast into the manifold where you can plumb the exhaust heat back into the header, most likely to the collector area. That will make the exhaust have a true full circuit path so it will keep moving through the intake, not just pulsing back and forth onto itself like the cheaper center mount intakes do.

Drilling different sized holes (1/2" and 1/4") on the left and right heat risers to create a pressure differential is another way to accomplish this, but that's just a band aid solution that's nowhere near as efficient as the factory VW setup or ACN deluxe intake. The return tube I plan on adding will be made like a straw sticking well into the collector at an angle. This will create a venturi effect to help pull the gasses through the intake.

The weather up here in the mountians of Western Montana is pretty much going to require me to use carb heat if I don't use duals. The elevation I live at (5K ASL) can, and has, produced snow during any time of year. The plan to fab up the PICT's as experimental duals will still happen, just not right away. I'm going to be using the single IDF setup first while I'm working out the bugs on the rail.

I know that I'm no wizard when it comes to carburetor tuning, so I plan on tipping the scales in my favor by adding in a wide band air/fuel gauge. Probably this one. http://www.ebay.com/itm/272052057318?_t ... EBIDX%3AIT This will be extremely helpful in getting the jetting down correctly, and also for later on when I look into adding a turbo system. If EFI becomes a possibility then I'll have that piece already in place.