67' S Weber identification

[scapone]

I currently own a 67' S and want to find out if the weber carbs on the car are original. Per Bruce Anderson's book there should be an "S" stamped somewhere on the weber IDA carbs as my car was built in 66'. Could someone please post pictures of where and what he is referring to. It would be greatly appreciated. Thanks. -Steve

[nick-moss]

It should be here



Also the IDS carbs uniquely have a high rev enrichment circuit that squirts via a curved brass tube into the top of the venturi

[pmjt]

It should be here

Nick - following Andy's post on the DDK that many '66 'S' didn't have IDS's fitted (can't remember the starting engine no.), I looked at the IDA's on my two '66 'S's (one mid August and the other September build) and they both have an 'S' stamped at the back plate of each carb - i.e. the piece on the back of the carb you'd see as you peer into the engine bay.

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[Fritz A. Ficke]

The S is behind the throttle return springs.

[Ernie W]

Starting engine number for IDS

[nick-moss]

Well done Ernie. Can't argue with that!

[scapone]

Thanks for the responses guys. I'm still a bit confused. The carbs on my 67S are 40IDA's and the only "S" that I see is on the part of the carb that faces the rear bumper of the car (if that makes sense) or the part of the carb that faces you when you look into the engine bay. The "S" is small and looks like it is engraved into it. My mechanic is putting new floats in my carbs so they are off the car. I went to look at them today. Nick, I noticed that mine don't have the high-speed enrichment circuit you're speaking of. So, long story short, am I looking at the correct "S" on my webers and if mine are IDA's w/ the "S" designation what makes them different than just the weber IDA (as they don't have the enrichment circuit of the IDS). Thanks

-Steve

[Richard]

Steve,
In about 1969 a friend bought a low mileage '67S from the original owner. The car was sold several years ago and I don't know the Vin or Engine number. However, as far as we know it was a completely original car, serviced only by the factory Porsche dealer in came from in Sacramento, CA. The Webers on it did not have the high rev enrichment tubes. In fact, back then the first time we became aware that these cars were supposed to have these tubes was a number of years later when his brother purchased a '68 Euro 911S which had them. (He tried these carbs on his car and for some reason they didn't work as well on his car as the ones without the high rev enrichment tubes.) I don't know what to make of this except that it's possible that your car, like his, came with carbs without those tubes even though it's an S. It seems to me that having these tubes should make a difference in that they deliver more fuel at high RPM's when needed...but the conventional wisdom is that they don't add power...that they are just there to prevent detonation of this high compression motor at hight RPM's. b.t.w., My 67S was built in late October, 1966 with an original engine number higher than the number in Ernies chart. The carbs are 40 IDS's with the high rev enrichment tubes. Looks to me like his chart is correct.

[scapone]

Richard,

Like your friend my car is a matching #'s car, so I have no reason to think that my webers aren't original. I think mine are just IDA webers with the "S" engraved in them and no enrichment circuits. I appreciate the input and info about your friends car.

[dvkk]

Here are some more details that can help date your Webers.

The studs that hold the carb top are cut threads, not rolled threads on the early Webers. The ends of the studs will be spherical in shape instead of flat. Early Webers also had regular M5 nuts, not nylocks like later carbs had. These early M5 nuts are a lot taller than modern hex nuts.

Notice the fuel inlet banjos in the lower pic Nick posted above. Those are the early type. They are all brass and are kind of conical in shape. Later ones are plated steel and are spherical in shape.

Look at the very top right of the top pic Nick posted. The early Weber logo has an E over the W. Later carbs sport the later giant W logo. I don't know if the triples were made when they went to the late logos.