Carb Question.

[swartie]

Hi,

I nned to repace my carbs, or so i have been told. I have seen a pair on ebay and would like to know what venturis are. and what size i would need.

i am running a 1641 twinport. cheers

Bradley

 

[Guest]

venturis are the throat or aperture down into the body of the carb, for a 1641 i would try to get 30s, no bigger. I'm fitting 32s to a 1955, im not going for big horses just fuel economy. The standard dual port 1600 (34pict/3&4 carb) have 26mm venturi.

VENTURI SIZE

Venturi size refers to the narrowest channel in the carburetor throat. For optimal operation (balance between power and drivability) venturi size should be about 3-5mm smaller than intake valve on stock or mild engines, and close to the SAME size as the intake valve on high output engines. You should also note that heavy vehicles must be more conservative with venturi sizing than lighter cars. All 2BBL Dellorto and Weber carbs have changeable venturis, so you DO have some tunability and re-sizing. However, venturis are expensive, so it's best to get close from the outset! Ask what venturi sizes are in the kit you are considering for your car. You want to get in the ballpark from the beginning since re-jetting a set of dual 2BBLs can cost from $100-150, and take a fair amount of time

The venturis are swapable, 'eurocarb' or someone else could advise and sell you on the right size for your application. As this says if you change the venturis you will alos need to rejet.