IDA carb expert's needed

[Ryan Tucker]

Hey guys i have my new 51 IDA’S torn down to learn them and rejet. First off im Very impressed with Webers design. For guys that read my 4bbl intake questions thread....im going to give you a 'you were right' no need to reinvent something thats already a great design and proven. I got my set of tall manifolds in and spent better part of a day porting them to match my big wedge port heads, they turned out good, also opened tops from 48mm to 52mm.

Now to my questions. Factory tune up was 130 mains under 120 airs on F7 tubes and 70 idles on 120 holders? 48mm vents

Ive changed it to 195 mains over 220 airs still on F7 tubes and left the 70 idles and 120 holders. 48mm vents

Does this still seem like a great starting point for a 12 to 1 type 1 2387

Also whats a good float level adjustment? With a .020 steel ruler and caliper i got 1.020" down from top to the needle stop. So basicly exactly 1 inch. This was the same base line float level in both carbs. Ive read where yall say its very important to chk and properly adj float level but cant find the tune up details.

One more thing i was thinking. Has anyone ever put a small balance tube from each side? Fixing to drill and tap each port for a home made fogger system, while the tig machine is running id wondered about adding maybe a 1/2" or so bung to each runner then plug them off for now. I was thinking later on the dyno i could add a section of hose across that ties in all 4 runners to a small balance tube. From there a tee could even be put in the center to pull vacum to like a crankcase vent or whatever. Whats yalls thoughts on this idea? Thanks

Also are my F7 emulation tubes good or shoukd i change them as well. And is any change needed to the 120 holder that holds the idle jets?

Sorry for so much info at once but any help here will be very appreciative

Ryan

[richierich]

I can tell you that on my 48's on my 2276 with similar heads to Wedge Ports and a Webcam 86C my jetting is as follows:

42 vents
160 mains
200 airs
60 idles
120 idle airs
F2 emulsions

I changed to the F2's from F7's and just prefer how it runs generally now.

My 48's have no 3rd progression hole.

I did spend a LOT of time trying to set the float heights properly. I kept getting it wrong and in the end, had a friend set them up who is an expert with these carbs. All I would say from my experience is, you MUST get the floats set right otherwise, it will drive you crazy.

Don't know how much help any of that is to you as your carbs are slightly larger than mine but hopefully it's of some use.

Here's the diagram for the floats:

[Ryan Tucker]

Yes Sir, thank you. Hard me me to decipher the schematic but looks like 22.4mm on what i was measuring. That divide by 25.4 is like
.882" or around 7/8". Where i now have 1".
Making this adjustment would lower the fuel level 1/8"

Would others agree with my math? Same with any carb if fuel levels too high it will bleed over causing a horrible idle, fouled plugs, washed cylinders, etc....

Anyone else have their good baseline with 51s?

Curious now about the F2 rather than my stock F7. Whats the difference

[HotStreetVw]

They are excellent carbs and you will enjoy the sound they make.

48 vents are serious. They are going to be more than your engine needs and it will make it difficult to tune. 190 main is close, I’d think a 180-185 will be closer. 220 airs will be wayyyy off considering 48vents. It will be extremely lean up top. I dynod with 48vents and found I needed a 195 main and 170 air to keep AFR reasonable from 5k+. It was rich down low, I think it needed smaller mains and an even smaller air. (Smaller the air the more fuel up top, they are opposite of mains and idles)

You're better off with 42-44 vents, 185s mains, 210 airs as a starting point. 44s are capable of a lot of power.

70 idle is 3 sizes to big. You need 55s.

http://www.aircooled.net/vw-carburetors-jetting-102/
_________________
4inBhore
50 Split - 2724cc NA. Haltech injected
62 Notchback - 2542cc Turbo WIP

[Ryan Tucker]

Also i totally dont understand their banjo fitting fuel inlet, its not threaded or have a male barbed piece or nothing. Nothing came in the kit to hook fuel line to the carbs.

I will be running 6an or 8an lines so id like a nice banjo fitting with appropriate an male hookup. Im certain -6 is pleanty of line size, agree?

[HotStreetVw]

For setting floats, you want the gene berg tool or a version of it.

https://www.thesamba.com/vw/forum/viewtopic.php?t=242163&postorder=desc

I machined my own. Makes setting floats very easy.
_________________
4inBhore
50 Split - 2724cc NA. Haltech injected
62 Notchback - 2542cc Turbo WIP

[HotStreetVw]

-6 is plenty.

http://www.jayceevw.com/store/p86/JayCee_Pro_Fuel_Inlets.html

While your at it, call Jack, tell him your combo, he will sell you those smaller vents and recommend jetting.
_________________
4inBhore
50 Split - 2724cc NA. Haltech injected
62 Notchback - 2542cc Turbo WIP

[King_vw61]

make sure you use a good fuel regulator, the carbs like 3.5 psi any more and fuel will leak everywhere. Aeromotive makes one for webers, also Shawn geers has one on his site. The holley ones are junk.

I have tried 60 Idles on a 2783 and it was too rich, 5.5's are perfect. Shawn said to run F11's for my engine. I have F2's F7's F'9s and F16's to play with. Also the 48 vents are too big for my 50mm intakes, for street driving anyways. I have 46's in now.

I sent my carbs back to Shawn to get his velocity stack and screens put on, he is going to set my float's and just go thru them once more. I was chasing a miss fire and just wanted to make sure it was not in the idle circuit's

[Ryan Tucker]

[Ryan Tucker]

[Ryan Tucker]

[Ryan Tucker]

[richierich]

[Ryan Tucker]

Appreciate that, thanks. While the floats were out i leak checked them under water, all was good. Opposite on race Holleys and bike carbs, we like to ditch the plastics and get good brass ones, so long as theirs no leak they are great.

Is the inlet banjo bolt a 12x 1.25mm???

[richierich]

[Ryan Tucker]

[maui]

My 90x94. FK 10 and I run 165/200/F2. F10/70 idle 42 vents and at sea level and run super nice. I tried 60s and it would stumble at part throttle going up hill and ran a little hotter.

[Ryan Tucker]

Internal passages of these big IDA's, will they support later a change to E85? What about the needle seat flow? Ive converted many 4 bbl carbs to full methanol never E85. Several passages have to be drilled out, bigger squirters, ~60% increase in jetting area. We used to drill a .125" hole in the main galley under the main jet then you still had fine control with original jet changes. Oh, and it Always required a much larger needle/seat to carry the volume. Of course 85% will not be as drastic. Anyone running their 48 or 51s on E85?

[HotStreetVw]

Not a lot of guys with IDA e85 experirnce. I swapped to injection to run it, but since I have IDAs and ignition system from before the swap, I’m throwing together an engine and plan to run the IDAs on e85 in my street Notchback. I guess we will find out about the same time if it can be done.
_________________
4inBhore
50 Split - 2724cc NA. Haltech injected
62 Notchback - 2542cc Turbo WIP

[Ryan Tucker]