Choke size in RACING 2.0

neilca · 03-13-2007, 09:04 AM

What size chokes are you guys running in your race only 2.0 liter carbs?

Thanks,
neilca

126coupe · 126coupe's Garage

I think you might be referring to venturis.
I run 36mm venturis in my 45mm PMO's
The engine is a 2.0L Race engine

jluetjen · jluetjen's Garage

Which racing organization? The SCCA limits choke sizes in the production classes.

neilca · 03-14-2007, 07:02 AM

Thanks Minkoff,

I was about to machine some 34 mm chokes and I wanted to be sure I wasn't going too big. These will be used in a set of 40mm Zentiths.

I consider what you call venturis to be chokes because they choke the air flow in the carb. I call the round center tube from which the fuel flows the venturi because it works on the venturi effect, the fuel flow is dependent on the air flow creating a vacuum.

shbop · 03-15-2007, 09:13 PM

Neil, You're correct. They are chokes.

jluetjen · jluetjen's Garage

Actually, both of the items that Neilca refers to work on the venturi effect. The larger items are commonly referred to as "chokes", but they are venturi as much as the secondary venturis.

304065 · 03-19-2007, 01:25 PM

A "Choke" is a butterfly that can be closed to block airflow to temporarily enrichen fuel mixture during startup. They come in three varieties: manual, water and electric.

That being said, they are called "chokes" in the Factory Weber Service manual so if that's what you are more comfortable with, there's certainly precedent for it!