weber carb conversion kit - PeachParts Mercedes-Benz Forum

bluebenz · #1 10-26-2007, 03:56 PM

Just bought a weber 38 dgas conversion kit from weber redline (kit 248) to replace the problematic solex on my 73 280C. The new carb fits in nicely but the linkage provided with the kit does not seem to make any sense. I searched the forum and found that others have had this problem but not clear how they fixed it. The redline help line has not been very helpful so far. Any help would be very appreciated!

Chas H · #2 10-26-2007, 07:39 PM

I looked at the website photo of your kit. There's not many parts associated with the linkage. Can you provide more detail of the problem, and perhaps post a scan of the directions?

bluebenz · #3 10-26-2007, 10:45 PM

True, not many linkage parts. But the parts provided with the kit are not the correct lenght to fit. It's not clear in the instructions whether you should keep some parts of the original linkage or not. But I'm expecting some photos from someone who successfully installed the kit. I'll keep you posted and try to scan the instructions.

bluebenz · #4 10-27-2007, 08:25 AM

To be more specific, with the original solex the linkage motion is north-south, with the weber the motion is east-west. There is an elbow provided with the conversion kit but no place to mount it, and the linkage that comes with the kit seems too short. I guess a picture would be better!

Chas H · #5 10-27-2007, 11:06 AM

I see in the website photo a place to mount the bellcrank on the extension out from the adaptor block using the bolt with the unthreaded body (stripper bolt).

bluebenz · #6 10-27-2007, 01:09 PM

Quote:

Originally Posted by Chas H

I see in the website photo a place to mount the bellcrank on the extension out from the adaptor block using the bolt with the unthreaded body (stripper bolt).

You're right. But logically the extension on the adaptor block should be on the rear left corner and then it would seem simple. The way it is now, when the adaptor plate is mounted the extension is in the left front portion of the carb. If I could flip the adaptor upside down it would seem to be in the right place. It is as though the adaptor block is not designed properly. But I am expecting some photos from someone who successfully did the conversion, and hopefully that will help!

bwostosh · #7 10-27-2007, 12:14 PM

Just rebuild (correctly) the Solex, save your money and headaches.
I've done those carbs, they are a copy of the Rochester Quadrajet..
Very good carb when done correctly.

Chas H · #8 10-27-2007, 01:40 PM

The other choice would be to mount the adaptor with the extension to the right rear.

bluebenz · #9 10-30-2007, 03:32 PM

Eureka!!!

Phoned redline weber again yesterday and they faxed me a diagram for the mercedes 280 solex application. It turns out that the generic instruction booklet provided with the kit says that the front of the weber carb must face the front of the car, but the linkage is impossible to install that way. On the correct diagram, it shows that the new carb must be rotated 180 degrees and then it is very easy to figure out!

I just wish they had included the correct instructions with the kit, it would have saved a lot of time and frustration! If you order the redline weber conversion kit, make sure they send you the correct mercedes linkage diagram!

dmtinker · #10 11-03-2007, 01:16 AM

If you checked an earlier thread of mine, you would see I had a similar problem. I had the 32/36 Weber kit and the directions I had were obtuse. All the instructions were there but in a weird order that was confusing. Also, mine had you retain the old linkage. You'd think for a $900 kit, they could put in $5 worth of new linkage parts.

bluebenz · #11 11-03-2007, 11:47 AM

Quote:

Originally Posted by dmtinker

If you checked an earlier thread of mine, you would see I had a similar problem. I had the 32/36 Weber kit and the directions I had were obtuse. All the instructions were there but in a weird order that was confusing. Also, mine had you retain the old linkage. You'd think for a $900 kit, they could put in $5 worth of new linkage parts.

Yes, I urge anyone buying the redline weber kits to make sure they have the specific instructions for their kit, otherwise they will waste a lot of time trying to figure it out!

Anyway everything is now installed, the car now starts very well cold or warm, doesn't stall and idles smoothly, but still has an initial hesitation on take off (? accelerator pump problem). A little more fine tuning and hopefully I'll be back on the road!

wbain5280 · #12 07-24-2009, 02:43 AM

Muscle Car just had an episode on rebuilding a Quadrajet.

http://www.powerblocktv.com/site3/index.php/watch-full-episodes/ep?ep_show=MC

mbbuff · #13 07-24-2009, 01:04 PM

My 4A1 works fine, always has, except when the float failed. I think I am the only one that has ever messed with this one. But, then again, I've worked with carburetors off and on for 40+ years. If I were to ever change (which I won't), I would adapt a 390 CFM 4160 Holley (List No. 8007, I believe) to the stock manifold. They offer more flexibility, and reasonably priced parts availability than any other mainstream carb. that I know of. Every system (idle, accelerator pump, main, power, secondary, etc.) can be custom tuned for your application. Linkage would also be easy to adapt using mostly stock components, IMO. Biggest problems would probably be mounting and adjusting the stock MB vacuum governor and making an adapter plate. Hmm, wonder if I should do this as an experiment. Carb. is only about $300-350.

wolf_walker · #14 07-24-2009, 09:04 PM

Quote:

Originally Posted by mbbuff

My 4A1 works fine, always has, except when the float failed. I think I am the only one that has ever messed with this one. But, then again, I've worked with carburetors off and on for 40+ years. If I were to ever change (which I won't), I would adapt a 390 CFM 4160 Holley (List No. 8007, I believe) to the stock manifold. They offer more flexibility, and reasonably priced parts availability than any other mainstream carb. that I know of. Every system (idle, accelerator pump, main, power, secondary, etc.) can be custom tuned for your application. Linkage would also be easy to adapt using mostly stock components, IMO. Biggest problems would probably be mounting and adjusting the stock MB vacuum governor and making an adapter plate. Hmm, wonder if I should do this as an experiment. Carb. is only about $300-350.

I've thought of this one as well, suspect fuel mpg would be icky with the size of the primarys. Who knows though. For the money and effort one could stick 2bbl TBI off a 2.8L GM v6 and it'd probly run alright on the stock maps. And they are quite tune-able these days.

mbbuff · #15 07-24-2009, 11:23 PM

Are those GM TBI's all electronic, or are they mechnical? If electronic, I wonder what kind of adaptation problems, especially wiring to the control unit, would be encountered? Could they easily be re-mapped, if need be? What kind of fuel pump and pressure do they use? Wonder what kind of parts availability they have? I agree though that a good FI unit would definitely be the way to go, if possible.

Years ago I used the 390 CFM Holley on a 250 C.I. Chevy (Nova) six, with a Muncie close ratio 4speed. Granted, the M110 engine is quite a bit smaller, but in the Chevy (as I recall) I got around 24 mpg on the highway....way better than the stock 2 bbl.
I have an old Holley sitting around. I think I'll pull it out and check it out to see how hard this might be. (I do love to tinker.) The good thing about the Holley is the vacuum secondaries. When set correctly they "size" the carb. to engine demand, so you're not likely to ever be over-carbureted, as you would with mechanically controlled secondaries. As far as the Rochester Quadrajet goes, I wouldn't consider it solely because of parts (tuning) availability. You'd have to hunt the junkyards, and know the exact models that had the parts you'd need. IMO, they were pretty good carbs. though, after about 1968.