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Weber DGV Series Carburetors

84B23F

84B23F

Well-known member
Joined
Feb 11, 2008
Location
Kansas, USA
These are 2-barrel, progressive, down-draft carburetors that are designed for 1200cc - 2300cc sized engines. 32/36 DGV sold in US, and 32/34 DGV sold in Europe were designed mainly for fuel economy, and 38 DGAS or 38 DGES for better “throttle response at a slight penalty in fuel economy.”

In USA, Redline ships kit versions of them tuned to specific stock engines. On non-kit versions, 22680.005 is jetted for 1600cc engine (Formula Ford 1600), and another, 22680.033B is claimed to be jetted for 2200cc engine at online retailers. In Europe, I've seen 32/34 DGVs jetted for different engine sizes.

These carburetors should be jetted for a given engine. Redline, the US distributor of Weber's products, has bundled kits available for specific stock-engines. Pierce Manifolds might jet them correctly if bought from them. “Weber Catalog and Adjustment Setting Tables” pamphlet(s) should be available to Weber based businesses. I only found this jetting table but if a kit is available and tuned for your engine, I highly suggest buying it.

There are two issues with a DIY jetting:
1. There are 5 different parts that must be considered, and
2. finding/buying these parts in US (I've seen European sites with them)

There is a “Weber Factory Tuning Manual” still available (book/pdf).

Weber offers a 32/36 DGAV-IC and 32/36 DGEV-IC carburetors which have a solenoid that shuts off fuel to the idle circuit when the engine is switched off. Apparently, in later model engines, this is needed to prevent “run-on” (dieseling) when engine is shut down.

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The B20 in the 75 is due for an overhaul. The shortblock is good, but the head is shot and the k-jets are dying. I'm sick of messing with the mechanical injection, and the lines are rotting one after another. I don't want to do an efi conversion, so carb is looking like a good way to go. The...
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I concluded there were misunderstandings about Weber Carburetors, which imho, are very good, if jetted correctly.
 
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Can confirm, jetting is spotty on new carbs and takes a little work to get it perfect for your situation and location.

Can easily convert the Weber to blow through if you wanted to maintain the turbo fun. Just remember it'll need a re-jet for boost.
 
MKUltra said:
Can confirm, jetting....for your situation and location..
Click to expand...

In carb heydays, I recall GM had at least one jet size listed for a higher elevation. Holley explains what to do for higher elevations. With Weber's carbs, more fine tuning options exist. When jetted for sea level, as elevation increases, the mixture gets richer, but if jetted for say Denver, the mixture gets leaner when descending in altitude.

Needless to say, it might be best to tweak for E10 fuel, which has some 3% less energy than reg. unleaded.

In that that jetting table for DCOE carbs, tweaking carb settings for a given cam should be considered. I can only wonder how the Mega users account for this cam-fuel tweaking.
Screenshot 2024-01-29 130908.jpg
 
i'm currently running a 38/38 from a penta 2.5L on a b23 with a k cam. it definitely runs rich, but that's okay for my application. it's a ripper wide open, little bit of a dog at low revs. playing with ign timing helps, would rejetting help more? also, planning on some serious head decking and possibly 100LL fuel. dunno how to jet for that.
 
swedishK said:
38/38 from a penta 2.5L on a b23 with a k cam
Click to expand...

I might suggest using a blended mix using E85, but "Currently, there are no public E85 gas stations in the State of Alaska."

Venturi can't be changed, but making a point here about different sized venturis:

Screenshot 2024-01-30 104301.png
so, when other changes are made to this carburetor, there are tradeoffs. If fuel mixture is too rich, some of this gasoline will end up in the oil, which can cause engine damage. If too lean, denotation.

Here is a link to Weber Factory Tuning Manual

A carburetor has to be torn down to determine what parts were installed.... their booklet explains these tradeoffs. I will say a carb for 2.5l is not ideal for 2.3l engine. I'm just now examing this jetting table...and it will take time to sort out what to do if I want to buy a carb (and save $450.00), or just buy a carb kit.
 
The problem with DGV and DGAS down draft carbs is they don't like vibration which Volvo engines (especially the push rod engines) have in spades. The AV will wear from vibration so badly that the fuel will just dribble into the engine between the body and AV. I've used brass shim stock to tighten them up and peened the carb body to keep them from vibrating to keep them in service but it's a temporary solution. I've also seen the brass tube in the AV spin so that fuel won't be drawn in at all.
 
hiperfauto said:
The problem with DGV and DGAS down draft carbs is they don't like vibration which Volvo engines (especially the push rod engines) have in spades. The AV will wear from vibration so badly that the fuel will just dribble into the engine between the body and AV. I've used brass shim stock to tighten them up and peened the carb body to keep them from vibrating to keep them in service but it's a temporary solution. I've also seen the brass tube in the AV spin so that fuel won't be drawn in at all.
Click to expand...
As far as I know this is a flaw with most webers and why anti-vibration mounts are common.

Also there is the off idle stumble issue that seems quite common across makes that see a weber replace an SU. It was really bad after a cold start. The progression holes just weren't right and no matter of different idle jets helped. I wasn't about to start drilling the thing either. Ultimately it was that and heat soak issues that saw me ditch it.
 
hiperfauto said:
The problem with DGV and DGAS down draft carbs is...
Click to expand...
Oh, another Ford product? Fix or Repair Daily? Cheaper to operate than a GTO? Gas Tires & Oil?

>like vibration which Volvo engines (especially the push rod engines)<

I notice Anti-Vibration Mounts available, but not for DGV/DGAS carbs. Is it possible Weber has improved their carb?
I'm not seeing any 'chatter' on this topic online, except for DCOE carbs. I hear nothing from MGBs having this issue. Redline has 'street legal' kits for older engines, but I have not heard about this issue.

I suppose a neoprene mount could be crafted.
 
spock345 said:
Also there is the off idle stumble issue that seems quite common across makes that see a weber replace an SU.
Click to expand...
If you are using the stock dizzy with the Weber carb, you either have the wrong carb or the wrong dizzy. It’s that simple. The advance profile of the stock dizzy is designed for the stock SU carb not a Weber..............I’d advise talking to Joe Curto, the SU specialist in NY,..

>heat soak issues<

This version might have resolved this issue
32/36 DGAV-IC...a solenoid that shuts off fuel to the idle circuit

I had this issue with small block chevies...stop vehicle on a hot day, and then try to restart it within 5/10 minutes.
 
Footnotes

1. - NOTE: Requires fuel pressure be regulated to 2.5-3psi.

2. The Weber DGV Carburetor Series
Thread Table of Contents (to be updated as thread continues)
  • Intro to DGV Carb Series: post #1 (with posts #7-13 for corrections and discussion over general info)
  • Exploded Diagrams (documents to download): post #2
  • Tuning & Troubleshooting Guides (documents to download): posts #3 and #31
  • DGV Carb Series Manuals (documents to download): posts #31, #35, and #40
  • The Synchrometer Tuning Tool: post #31
  • Other Tuning Tools: posts #4 and #31
  • What to Tune First: post #16
  • Charts on Throttle Position vs What To Tune and Reading Spark Plugs: post #36
  • Info on Main Jets and Air Corrector Jets: posts #4 and #16
  • Info on Emulsion Tubes: posts #4, #15, #16, and #43
  • Info on the Power Valve Enrichment System and How to Tune It: post #14
  • Info on the Low Vacuum Enrichment (LoVE) System, aka Anti-Stall System: post #1 (and in the uploaded manuals)
  • The Lost Art of Choke Adjustment: post #5
  • Info on Fuel Pressure Regulators and Fuel Compatibility: post #4
  • Info on Throttle Shaft Bearing Upgrade: posts #17, #19-30, and #37
  • Info on Troubleshooting a Squealing / Squeaky Sound: post #41
  • Info on the Holly Weber: posts #33 and #34
  • Other Related Threads: posts #6 and #41
 
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84B23F said:
If you are using the stock dizzy with the Weber carb, you either have the wrong carb or the wrong dizzy. It’s that simple. The advance profile of the stock dizzy is designed for the stock SU carb not a Weber..............I’d advise talking to Joe Curto, the SU specialist in NY,..

>heat soak issues<

This version might have resolved this issue
32/36 DGAV-IC...a solenoid that shuts off fuel to the idle circuit

I had this issue with small block chevies...stop vehicle on a hot day, and then try to restart it within 5/10 minutes.
Click to expand...
The idle cut off solenoid doesn't help with heat soak. It helps with preventing run-on or dieseling. Heat soak can be mitigated with a spacer, but it isn't cured.
84B23F said:
Oh, another Ford product? Fix or Repair Daily? Cheaper to operate than a GTO? Gas Tires & Oil?

>like vibration which Volvo engines (especially the push rod engines)<

I notice Anti-Vibration Mounts available, but not for DGV/DGAS carbs. Is it possible Weber has improved their carb?
I'm not seeing any 'chatter' on this topic online, except for DCOE carbs. I hear nothing from MGBs having this issue. Redline has 'street legal' kits for older engines, but I have not heard about this issue.

I suppose a neoprene mount could be crafted.
Click to expand...
The auxiliary venturis can still rattle around.
84B23F said:
Was fuel pressure checked?

NOTE: Requires fuel pressure be regulated to 2.5-3psi.
Click to expand...
It isn't a fuel pressure issue. It is an issue of a channel the main jet feeds having an opening due to improper fit of the auxiliary venturi. That opening will allow fuel to dribble into the carb whether fuel pressure is correct or not.

I am not sure if you understand the amount of experience that Hiperfauto has with these setups.
 
Yes, Webers are very sensitive to fuel pressure.

The dribble was caused by a loose AV. It needs to be a tight fit to the carb body.

Fun fact, the Redline street legal kits were developed by the owner of AEM. After he was done with the program he was allowed to set up shop inside the warehouse at Impac (now Worldpac) where they had installed a Clayton dynamometer to set up the kits. Initially he dyno tuned cars before going into manufacturing. He had full access to the Weber inventory as Impac/Worldpac owns Redline. He used to dyno my race car for free for running his sticker on my car. When Impac merged with Worldwide Trading to form Worldpac the former owner of Impac, now flush with tons of money, backed AEM financially and he moved out of the warehouse into his own building. He actually asked me to take over the installation side of his business when he was starting to get heavy into manufacturing but I didn't want to work on Japanese cars which were the bulk of his business.

EDIT:

I just googled him and saw that he passed away last year. What a bummer.
 
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spock345 said:
heat soak
Click to expand...

Second poster on this British forum gives a decent explanation

What causes heat soak, and is it a bad thing?​

"Heat soak is to be expected...Mostly, on older cars, folks just put up with it. "

Years ago, I pulled a loaded trailer with a dually pickup using a carbureted 454 GM on a hot summer day...yep, there I was pulled over and stopped, due to heat soak. This heat soak happened while driving this vehicle.

spock345 said:
The auxiliary venturis can still rattle around....due to improper fit of the auxiliary venturi.
Click to expand...

Thiperfauto suggested: "The dribble was caused by a loose AV. It needs to be a tight fit to the carb body."

So apparently, this issue can be fixed when it happens.
==================
>experience that Hiperfauto has with these setups<

That's good to know, and he may know as much as a factory rep in regards to this issue. I would like to think Weber is fully aware of this issue, and has attempted to address this issue with a service bulletin, etc. Would Hiperfauto know for certain this issue can't be resolved?
 
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