Weber jetting advice needed for 2.0
 

Hey guys. I haven't been back here much since finishing the rebuild on my 68L 2.0 in my 914-6. The good news is that a combination of BA's book, Wayne's book, this website and some local friends have made a nice little engine that runs great. I've been tuning the Webers (IDAs) and as normal it has taken a while, but it also got me thinking about my setup. Maybe some of you Weber experts can give me some advice.

My current setup is:
Main jet - 110
Air correction jet - 185
Emulsion tube - F1
Venturi - 27
Idle Jet - 55

I'm also running with a MSD 6a setup. She seems to be running well, and the plugs look like they are burning nicely, maybe a tad on the rich side. Is this an optimal setup, or can I squeek a bit more performance out of a different combination?

Thanks,

Dion

Dion,
When I had that combination (same as '69 911T), I went with the following for a slight improvement:

30mm venturis
120 or 125 main jets
Early S distributor

The engine is basically limited by the intake/exhaust port size, mild valve timing and low compression ratio. However, the relatively light weight 914-6 chassis should respond well to any mods.

I've still got the jets if you're interested.

Sherwood

What sort of cams are you using?

Hi John,

68 L cams.

Dion

Dion,
From Haynes Weber Carb. Manual for a 911L:
40 IDA 3C/1, 30mm Venturi, 125 Mains, 55 Idles, F26 Emulsion, 180 Air correction.
Braden's "Weber Carburetor Manual" says for a 911:
40 IDA 3C/1, 30mm Venturi, 125 Mains, 55 Idles, F26 Emulsion, 180 Air correction.
If they both agree, they must know something.
Whats with the F1 emulsions? I don't see them speced anywhere.
Looks to me like it was set up for improved mileage at the expense of performance.
Or it was set up for high altitude, over 5,000 feet. Way over.
Either way in Ohio you need to change some things.

2.7RACER IS Right on.
That is exactly how I would set it up if I had the same engine.
The jetting you are running looks very close to Zenith carb spec for a 2.2T.

Great feedback guys. Thanks for the setups. I own both of those books and didn't even think to look for setup info in there.

I have the jets on the way and am now looking for the other pieces, primarily the emulsion tubes and venturis. Anyone out there have these parts or can point me toward a good source? PMO I assume?

It should be interesting to feel this engine with that much of a change in setup. I've only ever driven this engine (before and after rebuild) with this 'high altitude' setup.

Thanks again guys.

Dion

From the 914-6 Factory Fuel Manual

Main jet - 105
Air correction jet - 170
Emulsion tube - F1
Venturi - 27
Idle Jet - 45

Ken

Over the years I've been collecting people's carb settings and results. Here's what I have so far for 2.0 engines (including yours). It would be great if you could post the results after you make the changes so that I can have "Before" and "After" entries for future reference.

http://forums.pelicanparts.com/uploa...1156945451.jpg

John,do you have the same for a 2.2 s by any chance?thanks muc,Marty

Thanks John for sharing the data. Seems like lots of setups all over the place, but also lots of engine purposes and uses. I'll let you know how it goes.

Dion

http://forums.pelicanparts.com/uploa...1157029083.jpg

Admittedly so, but I figured that if there was a configuration similar to what you are interested in, you could get an idea of what others have had for results.

John, Thanks for the info,let me add mine
2.0L 'S' engine, stock in the top end except for K&N air filter, sport muffler and twin plug heads.
Venturi : 34MM
Main jet: 150
idle jet: 55
air C. 180
E. tube: f-3
early 40 IDA carbs
I had factory settings and the power would tapper off at around 6,500 to 6,800 RPM now with the above bits it pulls hard to the 7,400 red line. I have not felt a real loss in off the line power but I do not drive this car hard at low RPM's. The engine is very seamless and smooth, Hope this helps, Fritz