Switching to triple Webers?

Johan_CS2800

Johan_CS2800

Well-Known Member
Site Donor
Messages
82
Reaction score
141
Location
Antwerp Belgium
Hi Guys,

In the short future I'm planning to switch the stock carbs on my 2800CS to triple Webers.
What are the big advantages aside from looks and sound?
Better performance?
More HP?
Easier to work on?

Would be great to read about your experience with these!
greetings,
Johan
 
I’ll be a jerk and say I would’ve expected you to have researched that before making the decision.

HP: I’m my limited experience you will get more when combined with other upgrades, starting with tubular headers, then cam changes, then porting to improve head flow, then modifications to allow a higher rpm redline.

Performance is a multidimensional individualized metric. How do you define it?

Ease: having had original Zeniths, and both sode/downdraft Weber, is day the side drafts are more convenient for physical access, but also more complex and costly to tune. In my experience, once tuned they are equally easy to maintain as the other types of carbs.
 
The advantage is that they are very flexible and you can adjust them for your particular engine, taking into account such things as compression, head design, cams, exhaust, and your timing curve. When setup, they perform well, sound great and look good. That said, you can achieve probably 90% of the performance with other carburetor setups that are not as complicated.

Flexibility can also be a huge disadvantage, particularly because isolating the effect of any given change requires patience, attention to detail and repeatable procedures. Moreover, there are no factory default settings to reference when you begin.

I bought a used set of carbs that were purportedly setup by a BMW restoration guy with a very good reputation. The jetting was off, float levels were wrong, and venturis were too small. She ran, but poorly. It took a fair bit of work to sort through this stuff. I enjoyed the process, learned a lot, and got a lot of help from folks here, particularly Stevehose.
 
Markos said:
I have a set of brand new DCOE 40’s I can sell. They are too small for my B35. Need to get some
45’s.
Click to expand...
I'm afraid import taxes from the USA to Belgium will be rather high.
Last year I paid about 30% extra on an alternator I bought on Ebay.
 
Johan, if you are truly after drivability, you should consider moving towards a fuel injected set up. Most notably a late motronic 1.3. It allows for temperature and altitude changes and seems to run correct all the time without ever any fooling around. The cost of conversion is probably about the same amount of money. We have the luck of having many old m30b35 cars here that can be purchased for very little money. I don’t know what exists around you in Antwerp. I’d rather have a smooth and reliable car with more power than the carbs can offer. Veel geluk met jouw beslissingen en jouw zoek. Mark
 
Go for DCOE pattern ITBs to reap the best of both worlds with regards to noise and looks as well as economy and reliability.
 
Oldbmwcoupes said:
Johan, if you are truly after drivability, you should consider moving towards a fuel injected set up. Most notably a late motronic 1.3. It allows for temperature and altitude changes and seems to run correct all the time without ever any fooling around. The cost of conversion is probably about the same amount of money. We have the luck of having many old m30b35 cars here that can be purchased for very little money. I don’t know what exists around you in Antwerp. I’d rather have a smooth and reliable car with more power than the carbs can offer. Veel geluk met jouw beslissingen en jouw zoek. Mark
Click to expand...
Thank you. Good suggestion, I am switching this winter to a m30b35 in my 73 coupe and I have been considering swapping the Webbers for Motronics or Megasquirt. Now if I can only find a good but reasonable mechanic to work on my car.
 
Johan, HP was the same , but we went down from the oem "300 NM" to only 240 NM torque !
We had to build longer inlet tubes ( and at the same time a air box and filter) to get again the 300 NM.

PS my (regularity rally ) E9 is for sale.... as i switched to a Porsche 928

SAM_3188.JPG


SAM_3210.JPG
 
You must log in or register to reply here.
Back
Top