Weber 40 IDS Enrichment Nozzles

[atomicboy]

I'm just in the process of doing a rebuild of my 40 IDS webers and have a question about the enrichment nozzles. When I took the nozzles out I found that they seem to be sealed at the base where they mount onto the carb body. It looks like a dab of lead. There is definitely no flow through them. What is the normal configuration of these nozzles? I can't seem to find anything on the web. My car is a '68 911S with 2.7 P&C's and headers. Also K&N filters and an MSD ignition.

Thanks in advance for any help,

Ron

[Flat6pac]

If they were working, they would be feeding the engine only at the upper RPMs. Years ago, the early 80 s I owned 307070S with the IDS carbs and that what I was told by the gurus of the day.
Bruce

[docrodg]

They are high speed enrichment nozzles, only come on at high RPM. As for the "sealant" I found an old weber manual and IIRC they are not noted to be sealed.

If you don't want the headache I will swap for my 40 IDA... Unlce owned the car and it failed smog in the late 90's and someone told him he had to change carbs so he swapped them out and did not keep them. The person doing the swap did not even give him anything for them, just called it even on the parts so he got taken.

[atomicboy]

Thanks for the input guys. I've had the car for 12 yrs and haven't had any issues so far, it always ran strong, but I just thought it odd that the nozzles were plugged. I know the PO so I'll contact him and see if he remembers anything. He rebuilt the car in '82 after finding it in a barn. Hopefully his memory goes back 28 yrs! Now I'm curious if there's more power to be had in the top end. As for the swap...........thanks, but I'll keep what the car came with.

Thanks again,
Ron

[Fleming]

If they have worked for some years it is probably a good indication there is no problem.

The enrichment circuit was a one year only, one model only item. (Well, actually 1967 and 1968 non USA 911S)

In talking with Bruce Anderson he asked if I was going to be driving at flat out rpm for hours - Autobahn style driving? If not - not needed. If I did : ) - still not needed. They were there to help enrichment at the very top end - only. And, with the different formulation of gas we have today the state of tune is not the same as 42 years ago.

Take a look at all the 2ltr thru 3+ltr engines that are running on Webers without the enrichment circuit - I don't think you are leaving "anything on the table" by not using them.

Bob

[atomicboy]

I was thinking the same thing (about not missing any power) since the PO who rebuilt the car had some help from an experienced Porsche mechanic so I assumed they must have been sealed up for a reason. I was a little surprised to find that the nozzles are a direct line to the float bowls. No jets/orifices of any kind. I'll stick to the adage "if it ain't broke, don't fix it". Although I know a few backyard mechanics who make me think, "if it ain't broke, they haven't fixed it".
Thanks for the input.

[1QuickS]

The nozzles have a little hole to allow gas to be drawn up from the fuel bowls. Hole size in the brass base is approximately 0.50mm (I don't have my current IDS project apart to measure the actual size.) If the lead is in the fuel gallery then someone put it there since these tubes are not needed but to let them get lost would be sad.

Paul Abbott
PerformanceOriented.com

[haycait911]

from what I understood when I had them, the fuel they dispensed was mostly intended for cooling the piston tops at the very high 'S' rpm and compression.

[1QuickS]

If this extra cooling was needed for the 911S then why weren't the enrichment tubes used on the 46mm Webers for race applications such as for the 906/911R/etc??? I believe the purpose was for extended high RPM usage as explained by Bruce Anderson as an autobahn application.

Paul Abbott
PerformanceOriented.com