What will happen when installed wrong secondary venturi

[hienz]

My Webers required long auxiliary Venturi
71104.450. I cannot find those original long Venturi. What will happen if I installed short auxiliary Venturi 71103.450 instead of 71104.450?

[john walker's workshop]

https://www.ebay.com/itm/PORSCHE-911-WEBER-40-46-IDA-CARBURETOR-LONG-AUX-VENTURI/292706200986?hash=item4426a62d9a:g:eSIAAOSwrwJbigr r&enc=AQADAAAB4KX%2FKt4E1xf3SDqEdBclaYbznTLVX%2FQrP9 g%2Bg4ZZH9%2BhA8Mq84G5M1cBHuVIcjFpeFKxyJxXfMOj7mtI qMiRO%2BHwWCVm7kkHeQVFqeVi%2BgYbHGe4fx3iKfgoT9vNJN 9gOM3fiZAERBWcNh1ZIOsnLQufn2EfvaltXOb8pimQB1e6n62Z mtLPUI9Wg4DbNIvPfUqFBitKhqbB2xt2yj7dlQ0rz4iVtOt5uW YvawTSh7J1MrKDUkDcWdUKDV%2BXEtv7uRYlPtBfoz7KFrpYMQ HJmdUIuA%2ByuE7tsoPp0unmS9kc7l3XL8%2Fp18RsoBRZYPYu TAPyhvJ8hF8Sxh3FLvYKg%2FxflJlTn%2BiZsaulJONlJ3udYY kk0DNotScobTftOGxI0AcX0AegSSz0DicJddftqBK%2FE%2BQ9 %2F7NnVIGwsBdf7DlOWMXZ8%2BCTkcDxrLx41doLAQ3gzqT%2F 5I0gqUz7OEpWfdGNEsm2dnbXuOBakQTpEvUnx7ksnZpaVyngkz uoaXgv7LXceRF6kUem0OnAN7V3bKktzgpOs8KzWyZsiyJrqG8W KLeG6MLtN7KpOOlZQB5M8GHaBobUEpm7eWdb8JXhAwBLBx7xtm vF2mH8kpEi3wg4dus6td5NxN62CJoI3ui3EQ%3D%3D&checksum=29270620098648be78c60add4081a19a7f87cb665 2b8

[juanbenae]

as I recall paul's (1quickS)performance oriented site explains the performance gain of tall v. short(er) secondary's. I had read here the talls were hard if not impossible to find these days. I did not think much of it at the time, but you may want to try pierce manifolds in Gilroy ca as a source for the talls. ive gotten a number of jets, emulsion tubes and other stuff from them for my webers. pretty good online catalog too, not great to navigate, but good description of what they have available. I think I remember them having venturi available.


thinking aloud here, and paul is likely to chime in but I wonder if PMO secondary's will cross over?

in the cliff note version of paul's take the tall units create more velocity that is better for high performance race applications, but there is no harm in using the shorter versions in a street car if memory serves.

[1QuickS]

I have been buying repros from the eBay seller "Alfa1750. They are OK.

https://www.ebay.com/itm/PORSCHE-911-WEBER-40-46-IDA-CARBURETOR-LONG-AUX-VENTURI/292706200986?hash=item4426a62d9a:g:eSIAAOSwrwJbigr r

[hienz]

Originally Posted by 1QuickS

I have been buying repros from the eBay seller "Alfa1750. They are OK.

https://www.ebay.com/itm/PORSCHE-911-WEBER-40-46-IDA-CARBURETOR-LONG-AUX-VENTURI/292706200986?hash=item4426a62d9a:g:eSIAAOSwrwJbigr r

Hi Paul,
That was the exact parts I am looking at on ebay, but the part# 71103.450.
However the picture show long venturi and the description indicated LONG-AUX-VENTURI. Alfa1750 also have long venturi for $45 and the part#71104.450

As far as know part# 71103.45 is for short venturi, and part# 71104.450 is for long venturi. Please correct me if am wrong.

If I was wrong then part# 71103.450 came in both long and short venturi
and part# 71104.450 came in only long venturi ?

I am now a little hesitated to buy the long venturi from Alfa1750 in ebay because they have part# 71103.450

[hienz]

Originally Posted by juanbenae

as I recall paul's (1quickS)performance oriented site explains the performance gain of tall v. short(er) secondary's. I had read here the talls were hard if not impossible to find these days. I did not think much of it at the time, but you may want to try pierce manifolds in Gilroy ca as a source for the talls. ive gotten a number of jets, emulsion tubes and other stuff from them for my webers. pretty good online catalog too, not great to navigate, but good description of what they have available. I think I remember them having venturi available.


thinking aloud here, and paul is likely to chime in but I wonder if PMO secondary's will cross over?

in the cliff note version of paul's take the tall units create more velocity that is better for high performance race applications, but there is no harm in using the shorter versions in a street car if memory serves.

Pierce Manifolds I just bought 6 metal type filter from them

[ajwans]

Do the tall type work with IDS carbs?

andy

[Quickstep192]

Originally Posted by hienz

Pierce Manifolds I just bought 6 metal type filter from them

Nice looking installation. Where did you get the very cool screen filters?

[Quickstep192]

I’m hoping to resurrect this thread.

I’ve always liked the look of these screens and it looks like the ones from Piece Manifolds really filter without restricting.

My question is: are the screens any problem when using the tall venturis? It seems to me that the top of the venturi will be pretty close to the underside of the screen; especially these flat top types.

[BURN-BROS]

Honestly I don't see those screens doing anything but restricting the airflow.

[r lane]

I have 5 secondary venturis, or emulsifiers, that may be what you are looking for. Get an email to me and I will send pics. Bob