Lets talk Emulsion tubes

[Caprimaniac]

Ok, Priobe- this have been into my mind as well; so: I will change air jets first and then see. If A/F is OK at wide open, and still around 10- 11 lower in the RPM scale,the exhaust has to be changed. Definitive.

I visited a racetrack last weekend and did alot of testing: In 4., the engine completely stalls at 4000 rpm, no matter what- if you gon on and off then on again; still the same. If you flloor the pedal; no answer either.
But; If revved to 7- 7500 rpm in 3., it hits 5000 or so in 4. and then it goes on (although not too far, the longest straight lets you go like 190 KMH (110- MPH), so I guess maximum 6200 in 4.?).
To be honest, the engine runs like crap, (is it weather- sick? it rained...) and I'm onto trying different things:
- Going to colder plugs
- Reducing the cold air scoop
- Removing closed "pressure box" around the carb air horns
- Using "boxed" K&N filters
(- Larger air jets and mesh filters for the air horns will go in next week)

Thanks for all the feedback

[Caprimaniac]

After alot of testing, this is what has come up;

I've done all of the above, even run NGK 7 plugs now.

The engine run really well above 4000 (up to somewhere... How long can it be stretched?).

It is still hesitating/ grumbling between 2000 and 4000 after braking through a corner and then accelerating. This is because of excess fuel.

Although shifting into 2. gives the punch, I'm convinced that a leaner bottom end will make the car faster as the time used for downshift + upshift will be larger than the time used for accelerate in 3. from 3000 and up...

What will be tried first is:
Use a smaller main fuel jet (from 165 to 145) and a smaller air jet (from 220 to 200). In theory, according to Mr. John Passini (if I read his words correct...?), this will make a leaner low end while keeping the upper end as is. Sounds smart, or?

The 2. choice is to follow Eljaro,Interesting Weber jetting, and use the F15 emultion tubes ("Tubes with bigger diameter for engines with strong vibration or high compression" and "Leaner low end and throttle response")

Runes

[Tomjohnsen]

Hello everyone.

Does any one have any f-19 and/or f-57 tube`s for sale? My carburator is DCOE weber.
If so, please send me a PM or e-mail me at christoffer_johnsen@hotmail.com

In advance, thanks

Tom Johnsen, Norway

[Gaz64]

Rune,

Your two next trial procedures both have merit and both are worth trying even if you are happy with the first outcome.

Back-to-back testing with a stopwatch and/or dragstrip acceleration test with a wideband O2 sensor fitted is also worth the effort.