carburetor selection

[piperstan10]

I am replacing a very old and worn out weber 34 ADF on my 73 124 spider which has a 79, 2 liter engine with a single plane manifold (76). I am thinking of a new Redline weber 32-36 DFEV - available new on Ebay for $339.

Anyone have experience with Redline or have a better option?

Also does anyone know what the DFEV means?

Thanks

Stan

[jwldane]

Hello Stan,

I have the 32/36 DFEV Weber on my car. It's a genuine Weber. This is what I can tell you about it.

It is infinitely adjustable, which is great....but that doesn't necessarily come easy. I am still struggling with getting mine tuned just right after a year a fiddling with it on and off.

You MUST adjust the float bowl. It is not correct out of the box. Be prepared to buy jets and replace them, especially the idle jets which are easy to get to on the outside of the carb. Have a spare gasket or two on hand. Proper fuel pressure is also critical.

Read up on the tuning procedures. Their will be some slight variations but get the lean best idle figured out first.

I can share with you some other resources and reading material if you like. Send PM and I get that to you.

John

[chrisg]

E means it has an electric choke. I think the F (vs. the common G) has to do with the orientation...usually you'd see the DGEV on 4 cyl BMWs, Nissans, Toyotas, etc. I have two of these, one a Weber, on an EMPI. I'm sure the EMPI suffers lesser metallurgical quality (or many would argue it does, at least!), but they both have worked well on my 1608 engines. I suppose there is a world where you order a carb, open the box & bolt it on, but the world I live in has always required spare jets, tuning, etc. (in part because whether new or used, I am usually running a carb set up for a 2L at the closest & mine is a different displacement & maybe different characteristics in general), so I'd count that as part of the deal for any carb you plan on using, at least potentially.

For many years, my go-to carb for a single carb & any twin cam was the 34 DMS(A) which was the stock '74 carburetor...pretty convenient, you just buy a '74 Spider and you have the proper clean manifold & carb right there, right? (even a more lively rear end to replace that sketchy '78-up unit with lower gearing if you want to do that too!)....Then years later, I tried a couple 32/36 DFEVs (ref'd above) on my 2 1608 cars and I've enjoyed them. If anything, they probably feel a bit more refined , maybe smoother....and, frankly, I prefer the more raw control of the 34 DMSA in the end. I'd expect most people would feel the opposite.

[piperstan10]

John:

Thanks for the input- I am surprised to hear that the float is not factory set! Is there a procedure you follow for float adjustment? I am familiar with setting the mixture - and the idle first!

How did you port the crankcase ventilation hose?

Stan

[bobplyler]

The DFEV will require a spacer to get to the correct height.

[piperstan10]

Thanks

Is the spacer for linkage or?

Stan

[jwldane]

Here is a link to a good carb tuning article.

http://sv3power.com/?page_id=371

There is three chapters.....read them all. This is only the link to chapter 1 but the other are linked from here. Redline's tuning procedures are also good but lees detailed.

My floats were at 36mm despite specs calling for 38.5mm. Definitely check and adjust.

The guys at Redline were very helpful. But the first thing they told me was to increase jet size. That's exactly the opposite of what I should have been doing. With my setup, 2.0 block, 1.8 head, headers, and the results I was getting everything was pointing towards a smaller primary idle jet.

Mark has been giving me some really good advice as well as John at aircooled.net. It's primarily at VW site but John has been incredibly helpful despite the fact I hadn't spent a penny with him. I just ordered some jets from him to get down to the 40-47.7 sizes I need to get dialed in correctly. I am certain that once this carb is jetted right it will be the perfect choice for both performance and fuel economy.

Let me know if you have more questions.

John

[donm]

How do you know if the float is out of adjustment? I have a Weber 32 36 which I installed about 3 years ago and the car runs fine. Does it make much of a difference? Is it worth checking if there are no symptoms of mis-adjustment?

[bobplyler]

Thanks

Is the spacer for linkage or?

Stan

It goes between the carb and manifold.

[carl]

Why do you say your 34 ADF is worn out? The ADF carbs are really simple carbs. Might make more sense to get a rebuild kit and just freshen up the carb you have.

[xjware]

I would love to have the 34 ADF over my standard 32 ADF

[jwldane]

donm.

The only way to check the float level is to remove the top of the carb. This can be done without removing the whole carb from the car. Once you have it out you measure the distance from base plate (without the gasket in place) to the edge of the bottom of the float. Best done with a digital or dial caliper. When measuring be sure that the float is only lightly resting on the ball valve and not depressing the value. The weight of the float alone can depress the ball valve and give a false measurement.

Why do this???? Especially is the car is running fine. Well, as I understand it, and I am by no means a carb expert, the Weber 32/36 DFEV (and maybe others as well) is designed to operate at its best within a certain range of settings. The mixture screw should be between 1.25 and 2 turns out from fully seated and the idle speed screw should be between 1 and 2 turns out from the stop. It is my understanding the outside of these parameters the carb may not be performing at its optimum and limiting the progressive nature of the carb. This can cost both fuel economy and performance.

As I said, I am no expert and I'm learning as I go. I have had a lot of help from many sources to get to this understanding of the carb. Some good and some not so good, but I am determined to try and get the very best result from this engine setup. Even on less than good settings, I am still able to drive the car, so there is no real down time involved. Its kind of like being a mad scientist, experimenting with different concoctions until you finally unleash Mr. Hyde.

John

[bobplyler]

I've never found the float level to be that critical.

[piperstan10]

Carl

I would much rather have the 34 ADF, It is at least 25 years old and likely can be rebuilt with a couple of issues;

First I need a vacuum port for the distributor -so I added one - unfortunately in the wrong place - I did not realize there was a location on carb and instead drilled through throttle body just barely above the butterfly and I think the location is too close to the butterfly - also after drilling it lookedlike there might be some internal porting at the location of the drilled hole. The new vacuum port hole is aboove and to left of idle adj screw.
I also heard that the newer carbs and jetting had been changed to accommodate the high ethanol/alcohol content..

So I figure I need a new throttle plate?

I also think the throttle bushings may need replacing and that's probably means a major carb rebuild?

Stan