Carburetor Question

[johan01]

FWIW, I have converted my Solex 4A1 4-bbl carburtor to a Weber. I have documented it in my web-page. Follow the links to the 250T, then click on the link about the Solex-to-Weber Conversion. I know its a 250 and not a 280, but both engines used the same carburator so its "foot-print" is the same.

I have pictures of the Solex 4A1 in the page, so if your carb looks like that, then you have a Solex. (BTW, the Zenith carbs on my 280S had "Solex" on a lot of parts INSIDE the carb)

The problem with the Solex 4A1 is that when it warps, it is close to impossible to mill it flat -- so once its warped, you have to replace it. Putting two gaskets may help, but it my case it didn't.

Weber carbs are simple carbs and are easy to work on, and they feature interchangeable jets and venturis so it can tuned for economy or performance. They worked well for my application.

best regards,

[hippie_elmo]

Originally posted by johan01
FWIW, I have converted my Solex 4A1 4-bbl carburtor to a Weber. I have documented it in my web-page. Follow the links to the 250T, then click on the link about the Solex-to-Weber Conversion. I know its a 250 and not a 280, but both engines used the same carburator so its "foot-print" is the same.

I have pictures of the Solex 4A1 in the page, so if your carb looks like that, then you have a Solex. (BTW, the Zenith carbs on my 280S had "Solex" on a lot of parts INSIDE the carb)

The problem with the Solex 4A1 is that when it warps, it is close to impossible to mill it flat -- so once its warped, you have to replace it. Putting two gaskets may help, but it my case it didn't.

Weber carbs are simple carbs and are easy to work on, and they feature interchangeable jets and venturis so it can tuned for economy or performance. They worked well for my application.

best regards,

The biggest question I have is, does the Weber conversion work? Since the stock is a four bbl and your putting a two bbl on. Is there the same power from the engine? I sent a email to a person who works at Jam and he said that allot people swicth to Holleys with a four bbl after they put on the Weber with 2bbl. Is your engine in your 250 the same as the one in my 280?

[johan01]

It works well enough on my car. Compared to the stock Solex 4A1 carb, my car starts better on the Weber, idles better, accelerates better, cruises smoother, AND gives same or better gas mileage. So to answer your question -- yes it works. BUT that was after several hours swapping jets to find what works best.

I don't doubt JAM Engineering's claim that the 4-bbl Holley works for them. In the US, Holley's are probably easier to get and there are a lot of people who know those carbs well. Their kit would probably work well "out-of-the-box" and would include all the linkages and hardware bits needed, but that's part of what you pay for. I exchanged e-mails with JAM engineering discussing carb selection -- I would have gotten their kit, but price and shipping cost was prohibitive.

I eventually went with the Webers because these are carbs that I can get locally and I personally understand -- I did the kit myself. It came out cheaper and now I have intimate knowledge on one system in my car.

BTW, I also received e-mail from one of the Weber kit suppliers and say that the Weber kit that they offer includes a 38 DGAS (38 mm throttle bores). They claim better fuel economy over stock, but a slight loss in high RPM power. How often to you go to red-line? The carb I used is a 40 DCNF (40mm throttle bores), and I don't feel the loss in high RPM.

regards,

[hippie_elmo]

Originally posted by johan01
It works well enough on my car. Compared to the stock Solex 4A1 carb, my car starts better on the Weber, idles better, accelerates better, cruises smoother, AND gives same or better gas mileage. So to answer your question -- yes it works. BUT that was after several hours swapping jets to find what works best.

I don't doubt JAM Engineering's claim that the 4-bbl Holley works for them. In the US, Holley's are probably easier to get and there are a lot of people who know those carbs well. Their kit would probably work well "out-of-the-box" and would include all the linkages and hardware bits needed, but that's part of what you pay for. I exchanged e-mails with JAM engineering discussing carb selection -- I would have gotten their kit, but price and shipping cost was prohibitive.

I eventually went with the Webers because these are carbs that I can get locally and I personally understand -- I did the kit myself. It came out cheaper and now I have intimate knowledge on one system in my car.

BTW, I also received e-mail from one of the Weber kit suppliers and say that the Weber kit that they offer includes a 38 DGAS (38 mm throttle bores). They claim better fuel economy over stock, but a slight loss in high RPM power. How often to you go to red-line? The carb I used is a 40 DCNF (40mm throttle bores), and I don't feel the loss in high RPM.

regards,

It will save me money both in the cost of the the Weber kit and maybe in gas too. Since I don't want to make a Benz a race car, all I want to do is make it work right. I did find the company that sales the 38 DGAS Kit and that Jam will sale me the 38 DGAS kit also. Is Weber still in business? Is there a differnet desgin in the Weber then the Holley. How do they tell the cubic feet per minute of a carb. (This is a stupid question).

[hippie_elmo]

Quick question is the below the Original carb. that came with the 1973 280?

SOLEX 4A1 DBP



Thanks for your help.

[johan01]

I believe the Solex 4A1 is the OEM carb in the 280. As far as measuring CFM, I really don't know. But I'll share with you some sites I visited when i was contemplating my carb swap.

http://www.ford-truck.com/articles/carb.html

and

http://members.aol.com/dvandrews/webers.htm

As far as I know, Weber is still alive and in business -- but I think their carbs are now made in Spain.

regards,

[DANTRCAV]

Yes, I have Webbers on my 250C and they were both made in Spain. They do, however, work quite well. I did have to jet them to fit my specific application but that was an easy task.

I am glad I made the switch.

Dan

[hippie_elmo]

Originally posted by DANTRCAV
Yes, I have Webbers on my 250C and they were both made in Spain. They do, however, work quite well. I did have to jet them to fit my specific application but that was an easy task.

I am glad I made the switch.

Dan

Is the Solex A-4-1 a electric choke or a electric water assist choke? How does the water choke work? Here are some pictures of my Pierburg carb.

[hippie_elmo]

Here is picture 2. Do you see any difference from the Solex and Pierburg?

[ctaylor738]

It's both. According to the manual, when the coolant temp hits 70-75 degrees Celsius, the choke is completely shut off.

I can send you the .pdf file with more info than you need, but your profile says that you don't want to receive e-mail.

Chuck

[hippie_elmo]

Well, still looking into the switch. A couple more questions:

1. The stock carb. is a 4-bbl and if I put the Weber on, would this damage the engine in anyway?

2. I have the information on the 38DGAS Weber kit from Redline and it says that it is a electric choke conversion of a electric water assist choke is the electric choke better? Does it make it easier to start? What is the differnce?

3. I live in California it says that the Weber is not legal in CA and is for racing vehicles which may never be used upon a highway. So I might have to install it myself. Is this hard? What tools do I need?

4. My intake mainfold is leaking how do I fix this? How hard is it?

5. I saw on a off-road Suzuki website that Weber carbs. are prone to stalling your engine when going up hill. Is this true?

6. I also saw on a website that the 38DGAS is a synchronous carb. (both barrels open at the same time). Is this true, and what does this give me?

[johan01]

>1. The stock carb. is a 4-bbl and if I put the Weber on, would this damage the engine in any way?

Only if you install the Weber with incorrect jets... eg: too lean,

>2. I have the information on the 38DGAS Weber kit from Redline and it says that it is a electric choke conversion of a electric water assist choke is the electric choke better? Does it make it easier to start? What is the differnce?

The Weber doesn not rely on water temperature to decide when to open the chokes. It makes for a neater engine compartment, since you won't have water lines going to your carb.

>3. I live in California it says that the Weber is not legal in CA and is for racing vehicles which may never be used upon a highway. So I might have to install it myself. Is this hard? What tools do I need?

Relatively easy. If you can remove the stock carb, you can easily bolt on the kit. My home-made kit used standard hand-tools to install.
I'm not sure about CA smog laws, but is your car smog except already?

>4. My intake mainfold is leaking how do I fix is? How hard is it?

Where is it leaking? At the manifold to head junction? Or at the base of the carb? If its the base of the carb, a new carb gasket (that should come with the kit) would fix that... unless the mounting flange is warped... so you'll have to get that milled flat. Sandpaper wrapped around a thick piece of glass would help.

>5. I saw on a off-road Suzuki website that Weber carbs. are prone to stalling your engine when going up hill. Is this true?

Mine doesn't stall on regular hills, even steep driveways. They're probably refering to really extreme off-road 'hills'.

>6. I also saw on a website that the 38DGAS is a synchronous carb. (both barrels open at the same time). Is this true, and what does this give me?

That is correct. Both barrels open at the same time. This simplifies things a bit since you won't have to worry about the secondary barrel opening (or not), and if it opens at the correct situation. Think of the weber as two independent single-barrel carburators siamesed into one carb body.

Happy New Year!

[cth350]

If your intake manifold is leaking, that would screw up your carb somewhat, yes ?

-CTH

[hippie_elmo]

Thanks for your help. I'm going to go with the Holley conversion so that I don't run into trouble with someone installing it. But I have a few more questions.

One the JAM Engineering website it has two conversion for my car.

1. C-505-CE: Mercedes 280 Legal Holley Conversion.
Holley "50-State Legal" replacement for Solex 4bbl carb on dual overhead cam 6-cylinder. Click here for a comparison of the "other" conversion, a two barrel Weber carb (left) versus ours, a four barrel Holley carb. Sorry, but at 295 cubic feet per minute the Weber doesn't even compare to the Holley's 450 cfm.

2. C-505: MBZ 280 basic Holley Conversion.
Doesn't come with idle-stop solenoid or evaporative canister hookup, '73 and most non US cars didn't have evaporative canistors.

Which one do I get? I have a 1974 280 that was made in 1973 as a 1974.

Here is a picture of the two and four-bbl. There is a big difference.

[cth350]

I'd go the 4-barrell kit specific to the car. If you really want to tinker, fix the 4A1.

-CTH