Stromberg vs Weber

[Kristian Jonsson]

Today you can buy an off-the-shelf finished 32/36 DGV conversion from one of the Alpine specialists.
I am thinking about it myself. It is supposed to be better in every way as a replacement to Zenith-Stromberg.
How can it be that much better performance-wise. Why can't a well adjusted Z-S set-up be almost as good?

 

[RootesRooter]

With the Weber on the old Series IV manifold setup on one of my SV's, it feels like it has one or two fewer HP than the Strombergs. Nothing dramatic. But smoother than the Strombergs.

I'd like to try out a Weber on the latest manifolds.

 

[spmdr]

Back in the '90s, I worked on several Street Alpines.

The Sweetest, best runner was an early series with a 1725

sporting a Weber 38/38 DGAS, I think.

Unfortunately, I don't know anything about the inner working of the engine.

I think the Accelerator pump was the key advantage over the Strombergs.

The throttle responds was head and shoulders above any other Alpine

I had driven.

 

[alpine_64]

The 38/38 DGAS is an outlier to the normal weber conversion. Larger and not a progressive but a synchronous carb... Better performance.

The dgv etc provide better fuel economy

 

[Tim R]

The new curved inlet manifold makes a big difference as each cylinder receives the same amount of fuel instead of two being rich or two being lean as with the 'log' manifold. If you couple it with the K&N Apollo air filter you have denser, colder air forced in from the front of the car instead of just having warm air sucked in from above the exhaust. As a result you get a noticeable difference in how the car responds.

We fitted one of the first of these Owner's Club' carburettor and manifold set ups several years and many thousands of miles ago. Apart from washing out the Apollo air filter and re-oiling it occasionally, we have not touched it since it was installed. It is a 'fit and forget' improvement.

Compared to Strombergs it is MUCH smoother and ticks over more slowly, acceleration is at least as crisp if not more so and we have never reached absolute top speed but would guess it is very similar. It certainly cruises at 70mph + with no problem for hour after hour. If you watch any of the videos in the 'Driving' playlist on the Sunbeam Alpine Channel on YouTube you will see how this car performs in daily use.

Apart from not constantly needing to be synchronised like the Strombergs there is no risk of diaphragms splitting (again).
We have this set up on two of our Alpines, on one we replaced a 28/32 Weber on a Log manifold. It is a very good improvement that you will not regret, (your miles per gallon will go up too).
Tim R

 

[Hodee]

is the curved inlet manifold available through the same vendor as the carb?

 

[Tim R]

The curved manifold comes from Alpine Innovations who supply the carb set up specifically for an Alpine.

Tim R

 

[alpine_64]

is the curved inlet manifold available through the same vendor as the carb?

There was a group manifold purchase by saoca members a couple months back

 

[Kristian Jonsson]

How is the DGV jetted?

 

[Shannon Boal]

How is the DGV jetted?

I installed "Alpine Innovations" complete kit, drove to SUNI VII and back, with out of the box jetting. It was a bit stumbly off-idle, especially with ethanol blend fuel. I replaced the idle jet (number 525 or 0.525 MM) with a ( number 55 or 0.550 MM) jet and it is very, very good. The jet should flow about 12% more than that which it replaced. The other jets are listed in other posts, IIR, primary is 135, sec is 140

 

[Kristian Jonsson]

What other posts? What engine do you have? Standard Alpine SV?