bigger venturies = better driveability?

[alex d]

I recall reading something in the other forum some years ago about someone that reported that got better driveability when changing 42mm for 44mm venturies or something like that, does anyone here remember what I'm talking about?

[BeetleBug]

I recall reading something in the other forum some years ago about someone that reported that got better driveability when changing 42mm for 44mm venturies or something like that, does anyone here remember what I'm talking about?

Probably because the engine runs like a slug with too big venturis = slower = safer = better on the street.

Just my 2 cents.

Best rgs
BB

[Peter Roberts]

It was probably me , I followed the Advice of Mark Herbert , as I often chatted to him over email .

I tried what he suggested , and it worked out just fine for what I was working on .

[Jim Ratto]

I recall reading something in the other forum some years ago about someone that reported that got better driveability when changing 42mm for 44mm venturies or something like that, does anyone here remember what I'm talking about?

yeah it was Herbert. he had a theory that the bigger vents lessened the strength of intake reversion pulses going through emulsion tubes. Does it work? I don't know but it was smart thinking on Herbert's part. The main jets operate on a principle of vacuum, though I don't think it matters which direction the vacuum is headed. The reversion pulses, I think Mark theorized, were getting the main to send fuel up to the sky.

Now my car?... it runs best with 40mm vents out of the 37's, 40's and 42's I've tried it with. 37's ran into a wall and ran lean on bottom (to avoid a wall of richness up top). The 42mm never pulled hard. 40mm run terrrific from idle on up to 7K.

kind of a loaded question. Depends on rest of motor, gear ratios, weight...etc.