weber DGV vs. strombergs?

[mightyohm]

I know there are a lot of fans of the Weber DGV. It's simple and reliable. But is anyone running Strombergs that prefers them over the DGV? It seems like 2 carbs should flow better than one.

 

[alpine_64]

Jeff,

If by flow you mean cfm... That will be determined by the throat and chocke size. If you have a dvg/dga/dgf etc with larger throats than the stock twin carbs (zenith wip/wia or strom 150cd) then the compound will flow more.

If you mean that 2 carbs offer better more direct flow due to manifold design... Tgat depends on the compound manifold.

The 2 true advantages of the single weber are
1. it wont go out of sync like s twin setup can, the convenience advantage.
2. If you have it set up as stock progressive it saves fuel as the second throat opens up at higher rpm where a twin setup always opens both throats. Though you can add a sync link so both throats always open for more performance.

All that said... I love twin carbs, for look alone and performance.. Hence i have twin 40 dcoe :-D

 

[Tim R]

In my family we have Alpines running on both the latest Weber DGV with the free flow induction manifold developed by the U.K. owners club and marketed by Alpine Innovations and the standard (fully reconditioned) Strombergs. There is absolutely no comparison. The Weber set up is smoother throughout the rev range, more powerful, stays in tune and is literally a fit and forget option. With the Stroms you need to balance them fairly regularly, the dashpots need topping up, the diaphragms can split (which is a real pain if you happen to be away on trip when it happens!) and the T pieces can break.
If you fit a Weber and a good quality electronic ignition you have made the car significantly more reliable and much more like a 'modern' car to live with.
Tim R

 

[65beam]

I think Tim hit the nail on the head. There's an old saying that goes back many decades about owning a British car. "Drive it during the week and work on it during the weekend". These are old cars and unless you have nothing else to do but fiddle with the car on a constant basis then don't upgrade to items that simplify life with the car. The Weber is one of those upgrades that keeps it simple and on the road.

 

[65beam]

I know there are a lot of fans of the Weber DGV. It's simple and reliable. .

This car was simple and reliable. A 32/36 or strombergs would probably have drowned the engine. Me and my Anglia in my senior year of school way back in 1967. It had a 997 cc engine.

 

[mightyohm]

Jeff,

If by flow you mean cfm... That will be determined by the throat and chocke size. If you have a dvg/dga/dgf etc with larger throats than the stock twin carbs (zenith wip/wia or strom 150cd) then the compound will flow more.

If you mean that 2 carbs offer better more direct flow due to manifold design... Tgat depends on the compound manifold.

The 2 true advantages of the single weber are
1. it wont go out of sync like s twin setup can, the convenience advantage.
2. If you have it set up as stock progressive it saves fuel as the second throat opens up at higher rpm where a twin setup always opens both throats. Though you can add a sync link so both throats always open for more performance.

All that said... I love twin carbs, for look alone and performance.. Hence i have twin 40 dcoe :-D

How do the cfm numbers of the 32/36 DGV compare to a pair of Stromberg 150's?

 

[mightyohm]

In my family we have Alpines running on both the latest Weber DGV with the free flow induction manifold developed by the U.K. owners club and marketed by Alpine Innovations and the standard (fully reconditioned) Strombergs. There is absolutely no comparison. The Weber set up is smoother throughout the rev range, more powerful, stays in tune and is literally a fit and forget option. With the Stroms you need to balance them fairly regularly, the dashpots need topping up, the diaphragms can split (which is a real pain if you happen to be away on trip when it happens!) and the T pieces can break.
If you fit a Weber and a good quality electronic ignition you have made the car significantly more reliable and much more like a 'modern' car to live with.
Tim R

Tim, your experience and insight is very helpful! How does the throttle response of the Weber compare to the dual Strombergs? I've always wondered if the dual carbs would feel more "snappy" since both throats open at once.

 

[mightyohm]

I think Tim hit the nail on the head. There's an old saying that goes back many decades about owning a British car. "Drive it during the week and work on it during the weekend". These are old cars and unless you have nothing else to do but fiddle with the car on a constant basis then don't upgrade to items that simplify life with the car. The Weber is one of those upgrades that keeps it simple and on the road.

My car has a Weber 32/36 DGV and you are correct, it has been very reliable.

 

[husky drvr]

Jeff,

Holley considerers the Holley 5200 series of carbs to be rated 270 CFM @ 3.0 inches of Mercury. The 5200 is the Holley copy of the Weber DGF made for emissions controls (used on Pintos and Vegas, etc.). I think if the 5200 was rated the same as a four barrel at 1.5 inches of Mercury, then it would only be considered to flow about 190 CFM.
I'm not sure that I have ever seen a flow rating on the Zenith-Stromberg carbs. Considering the variable venturi design, flow would be dependent on the parts assembled in the carb. A stronger piston return spring could reduce venturi opening enough to change the flow rating. A stronger return spring would also require a different profile needle.

For what it is worth, the Alpine's 1725 used a pair of CD150's compared to Triumph's TR-4 using a pair of CD175's on its 2200 cc engine. Less than half of a liter displacement required the use of a larger pair of carbs. IIRC, the 150 and 175 refers to the size of the throttle bore at the rear of the carb in inches.

HTH

 

[alpine_64]

Tim, your experience and insight is very helpful! How does the throttle response of the Weber compare to the dual Strombergs? I've always wondered if the dual carbs would feel more "snappy" since both throats open at once.

John,

You can buy a sync linkage for your dgv that will open both throats. You will lose some fuel efficency but gain some lower end punch.

That said you may need to fiddle around tunning incase it richens it to much and bogs the motor.

Running a high output electronic ignition helps with a nice fat spark and if you go multi spark like msd or crane it certainly helps overcome any low end richness.

Just .02

Go all in and go twin dcoe

 

[Tim R]

Mightyohm,
In my personal opinion there is no comparison between the new Weber set up and the twin Strombergs. The UK owners club developed a curved inlet manifold for the new Weber DGV together with a K&N Apollo forced induction air filter kit. The curved branch manifold makes all four pots respond identically (as opposed to the original single carb 'log' inlet manifold which causes fuel puddling in branch 1 & 4 and consequent rich running there). The improvement is marked. Acceleration is smooth and powerful from tick over (which is super low at a very smooth 500rpm with the new set up) all the way through to flat out. I have had Webers (either 28/32 or 32/36) on original style 'log' manifolds on Alpines before, usually with a simple pancake mesh filter on top. The new system is far superior to this. On one of our cars the head has had the Vizzard modification. Coupled with the new Weber carb, an original 1960s mild steel Abarth free flow power exhaust and electronic ignition the engine is so smooth that it barely moves at tick-over. Open it up and it flies along!

John,
Some people in the UK are now ditching their twin DCOEs for the new twin choke single carb set up because of the the advantages that make it so much easier to live with.

Tim R

 

[alpine_64]

Mightyohm,

Some people in the UK are now ditching their twin DCOEs for the new twin choke single carb set up because of the the advantages that make it so much easier to live with.

Tim R

Lots of people do various things for various reasons. It took me a while to dial in my 2x40dcoes, partly due to engine spec ans then learning curve of the fine adjustments that dcoes have.

Once i got them sorted they have been fantastic, in 15 years they never went out of sync and the only issues i had were a blown o ring soft mount gasket between carb and manifold once amd some crap in one carb due to me not running filters at one point. This car was daily driven for 6 years in that spec as well.

Dcoes are not the answer for everyone, but set correctly the only disadvantage to a dgv is fuel consumption. They outperform the single on every level.

I appreciate the effort that went into the new manifold setup. Its great to have new parts developed for the cars ( congrats to all involved)

I know how many people are happy with it ( that said have also seen a few come up for sale from people have have gone back to twin carbs)

Personal opinion on the new setup would be to ditch the filter setup.. It looks like a 1980s compacts engine bay.. Or a rice cooker... Pity as aesthetics of an alpine motor are a draw.

The original question was about Stromberg setup.. I know correctly rebuilt ones run very well and are reliable. They do require some service occasionally but its no different to regular maintenance. I cant answer the exact performance difference v a dgv... And will vary these days depending on condition of carbs.. Setup and driveline condition/ modifications.

The dgv is a set and forget. There are work arounds for the stumble they often have.
The new uk manifold might be an even better option bar aesthetic consideration. Dcoes are the ultinate for me for every level bar efficency but are costly initially.

As always your milage may vary ... As long as we are all enjoying the cars and driving them :-D

And why i love opening my bonnet ( hood)

 

[mightyohm]

Michael, that is an impressive setup! I see you had to ditch the stabilizer bar on side with the carbs to make it all fit!
I think the RHD cars have an advantage in that they don't have the steering box to contend with when fitting DCOEs, I think this is well documented on the forums.
That is a slick throttle linkage setup, is it custom?
I agree that the aesthetics of the DGV air filter could be improved. I like the look of the dual carbs too.

Tim R - I have the Alpine Innovations kit and I plan to install it once I get the car back together. The new manifold is very nice and was the reason I bought the kit. I liked the design of the manifold - it's lighter weight, has what appears to be a better runner design, and allows the carb to sit lower. The kit also includes a new throttle linkage setup which should be a big upgrade over what I had in the car. I did replace the grommet they use on the throttle braket with one made from hard plastic, as I didn't like the drag of the rubber bushing that comes installed.

My current plan is to get the car back on the road and break in the new motor with the DGV because I have a fair amount of experience with that carb and it should be easy to get the car running. Later on down the road I'll perhaps look into dual carbs again to keep things interesting.

 

[mightyohm]

Jeff,

Holley considerers the Holley 5200 series of carbs to be rated 270 CFM @ 3.0 inches of Mercury. The 5200 is the Holley copy of the Weber DGF made for emissions controls (used on Pintos and Vegas, etc.). I think if the 5200 was rated the same as a four barrel at 1.5 inches of Mercury, then it would only be considered to flow about 190 CFM.
I'm not sure that I have ever seen a flow rating on the Zenith-Stromberg carbs. Considering the variable venturi design, flow would be dependent on the parts assembled in the carb. A stronger piston return spring could reduce venturi opening enough to change the flow rating. A stronger return spring would also require a different profile needle.

For what it is worth, the Alpine's 1725 used a pair of CD150's compared to Triumph's TR-4 using a pair of CD175's on its 2200 cc engine. Less than half of a liter displacement required the use of a larger pair of carbs. IIRC, the 150 and 175 refers to the size of the throttle bore at the rear of the carb in inches.

HTH

Don, thanks for the info. I'll have to hunt around for some cfm numbers for the 32/26 DGV and 150CDs and see how that compares to the numbers for the 5200.

 

[65beam]

Michael,
What is the small tag at the top of your VIN plate?

 

[Tim R]

Mightohm,

Make sure that you fit the blanking plug in the inlet manifold and NOT the PCD valve and don't miss out the heat insulator. Vent the tappet chest to atmosphere or fit a sealed tappet chest plate (as used on the later 1725 engines) and dump the PCD. If you fit the PCD valve on the new manifold you will weaken the mixture on cylinder 4 under hard acceleration (on standard Series Vs the PCD was originally shared between all four cylinders). We use the forced induction kit and have blocked the horn apertures to increase cooling (Tiger style). This way only ambient temperature air gets force fed to the carb rather than hot engine air re-circulating and ending up in the carb intake and reducing power.
Tim R

 

[alpine_64]

Tim think you mean pcv for the engine.

As a side note thats a verrrrry nice siv you have there!

 

[Tim R]

I thought it was PCD! I'll say PCV in future. The Series IV belongs to my eldest. My youngest has a Series V as do I. They bought their cars when they were 13 years old and spent the next 4 years doing them up so that they had nice cars to drive when they were old enough. They are both in their late 20s now and their cars are still lovely.
Tim R

 

[alpine_64]

I see you had to ditch the stabilizer bar on side with the carbs to make it all fit!
That is a slick throttle linkage setup, is it custom?
things interesting.

John, i used the redline manifold which is essentially a copy of the Warnerford gooseneck. This is the easier option for lhd as the manifold picks the carbs up higher which avoids the steering box issue but makes it tight for the m/c iirc. I have a new straight in short manifold but used the gooseneck to get longer runner s and allow me to run the holbay extended auxiliary venturis and velocity stacks to help with lower end torque. But yes required removal of the scuttle brace.

As for linkage its all parts from redline. I used a central connection to help with carb sync instead of one for each. If you use the weber yoke fitting you can sync by just adjusting the screw on the linkage. That said ive found the dcoes very stable. They only even seem to need tweaking if i take them off the manifold.

 

[alpine_64]

I thought it was PCD! I'll say PCV in future. The Series IV belongs to my eldest. My youngest has a Series V as do I. They bought their cars when they were 13 years old and spent the next 4 years doing them up so that they had nice cars to drive when they were old enough. They are both in their late 20s now and their cars are still lovely.
Tim R

Pcd is wheel stud spacing, pcv is for the crack case ventilation (the pcv valve achieves this)

Great to get your kids into the marque early... My sii was my first (and still is with me ) car.
Had it since i was 17 .. Back in '96!.... Eeek.