Date code on webbers

[Bivvv]

Hi
Continuing to dig, would there be date codes on 40IDS3c webbers, If so where?
Thanks Bret

[friggens]

I do not know about a date code, but they only used them for a few years, right? Like 1967 and 1968, 68 only in Europe or did the L have IDS? Other cars that used the triples had different numbers/letters as well, so should be no mistaking the right ones - unless an ebay seller marks them incorrectly, takes them down and relists them once he realizes they are IDS, not IDA

cheers - Mike

[Bivvv]

Hi
These carbs are on the prototype engine 900054 901/02 what does the yellow tag distributor look like and can you tell s heads from normal heads without taking off.
Thanks Bret

[1QuickS]

Date codes were something like "5C" and were used after Porsche stopped using carburetors on OEM engines. All Webers supplied on 911 type engines (914/6 also) used serial numbers and were anything from a single digit up through four digits. These serial numbers are located in the horizontal raised metal strip directly below the model identification number.

The earliest 911S engines used 40IDA3C and 40IDA3C1 carburetors but were identified with a small "S" stamped on the end of the throttle body to denote jetting for the "S" engine. Per Porsche records the "IDS" stamped bodies with the high speed enrichment tubes were introduced into production with engine #960502.

Picture shows the "S" on a 40IDA3C1 throttle body (driver's side):

[Bivvv]

Hi Paul
Thank you for the valuable info if I have the #1841, 1818 is there a site to see when these were produced. These are on an engine that was a versuch prototype so I am thinking this was part of the testing for the change mid year on the S. This car was completed in 12/66 and spent the first 9 months in the versuch dept until it was sold internally.
Thanks Bret

[1QuickS]

Serial numbers are hard to match up...I have not made the effort to correlate VIN #s to carb serial numbers. I do know from those I have serviced and from my own car as well that IDS carbs were in place by Oct66 and probably earlier than that. Webers for the 911 replaced Solexes in March66 (VIN and engine numbers are subject to much dispute on this site). When the IDS carbs were introduced the unique throttle body castings required for the high speed enrichment feature of the IDSs were incorporated for all subsequent IDA3C type carbs. IDA carburetors manufactured prior to the casting changes for the IDS are recognizable by their lack of the three additional galleries.

There is a good photo on my web site showing these galleries: http://www.performanceoriented.com/t...tm#FuelGallery

Since your engine was a "test engine" then the carburetors were most likely changed frequently and could have been from any series of IDA/IDS carbs. Much like race applications I suspect that carburetors for test applications were not matched to a particular engine.

As a backup to the last statement: I recently serviced two sets of 46IDA3C Webers that came to me from two of the twenty 911Rs assembled in early 1968. These Webers did not have the updated castings as I mentioned above which told me the carburetors were cast prior to mid 1966 and from that earlier inventory purchase only made it onto a car in 1968. In fact, I believe these carburetors were probably acquired from Weber in support of the 901/21 engine which was first installed into the first 906s (904 chassis with 901/21 engine) earlier than Dec 1964.

Since Porsche launched the 911 with Solex carburetors and used Webers for their race engines I postulate the first Weber carburetors for production engines were cast after the 46mm throttle bore Webers for the 901/21 race engines.

If your carburetor serial numbers are in the 1800 range then I believe them to be of a series fitted to production engines later in the 1967 production run. I can tell by looking at some photos and make a pretty good guess as to their heritage.

[Bivvv]

Hi Paul
Later in the 67 Production run would make sense. The first owner did not take possession of the car until September of 67. I am starting to think that this engine may have been a development engine for the 2000r sportkit cars of 68, that coupled with the original owner being an ex machinist and Factory racer Jochen Neerpasch. How long have you been in Chico I was a student from 88-91 with a white 912 for a while. I tried to figure out how to stay but couldn't, a few friends did, Land-Image and Chico Brewhouse. It is a great town, it sure has grown in the last 20 years. Thanks for the help Bret