spyderman

hey Steve, a long while ago I askes you about a the set up on some carbs, the motor is a 2.7 with 8.5 RS, P+Cs GE 40 cams, heads cut, intakes bored to 35mm, stock valves, SSIs and a sport muffler.
you suggested I use 34-36mm venturies, tall aux venturies, 155 mains, 180 air corrections, 60 idle jets, and F3 emulsion tubes.
I am going to go with the 36mm venturies,
One question I have though is about the emulsion tube. In the carbs there are F24 tubes. what is the difference between them, and what difference will that make?
Also, where can I get a set of the taller Aux venturies?
and can you recommend any one to recurve my original 't' distributor? or is their anyway I can just buy different weights and springs and do it myself?
thanks
-Ken

Steve Weiner-Rennsport Systems

Hi Ken:

LOL,..You must have been VERY sure that I would be the first responder,......

The difference in emulsion tubes are when they begin flowing fuel as the throttle opens from just above idle to WOT. These are matched to each camshaft's characteristics (intake vacuum) and make a big hole in the throttle response if they are the wrong ones.

F24's are matched to T cams. F3's are matched to S cams and they work very nicely with your configuration.

The tall Aux venturies are now out of production (they were made for the 906) but sometimes one can find a set by looking around.

There are not premade advance kits for these Bosch distributors and neither Porsche nor Bosch ever sold those parts separately. One really needs to have it setup properly in a distributor machine. Sometimes I do this when I'm not busy but you might find someone locally,..............

spyderman

Ha, yea, I read these threads alot, and I noticed you really jump for the really technical questions. Can you recommend any good books or manuals on the weber carbs?? some that are really technical?
Thanks
-Ken

Steve Weiner-Rennsport Systems

Generally speaking, I look for the stuff that nobody can or will answer (accurately),...

There are few good books on Webers anymore and most do not have much on the 3-bbl carbs.

You should have the Haynes Weber manual and Pat Braden's Weber book in your library. There are some long out-of-print Weber factory manuals but they are REALLY tough to find anymore.

These books are NOT Porsche specific so if you are looking for that sort of thing, you are out of luck as nothing ever existed for 911's, unlike the 912 & 356 cars.

The people who really really know the 3-bbl Webers (and PMO's) are folks who have successfully raced with them for many years and have a LOT of experience.

spyderman

so what are you saying? you don't take the time to research and answear questions about lip spoilers and what tools are needed to torgue lug nuts?? ha, I hear ya. I found a set of the longer aux venturies. What are the advantages of them?? And thanks for the recomendations on the books, ill check them out.
-Ken

Steve Weiner-Rennsport Systems

Ken:

LOL,..There are others that are FAR more qualified than I that can address those issues.

The tall aux venturies were made for engines with aggressive cams that develop very little manifold vacuum at low engine speeds. These tall venturies increase the vacuum to the main jets/float bowls to help get fuel flowing, sharpen throttle response, and help prevent flat spots in the 1000-4000 RPM range.

0396

Steve,

Can I utilze the same set-up on my 3.4 - 10.5 compression, s cam, twin plug?

Thank you .

Peter

Say hello to Dick for me

Steve Weiner-Rennsport Systems

Hi Peter:

Yessir, those will work just dandy in your 3.4,....

I will see Dick this evening and I'll be sure to tell him hi.

0396

Steve,

Thanks for responding!