Weber conversion, tips?

[Wayne67vert]

I've ordered a Weber conversion for my Series 5 Alpine. Are there any tips or tricks I need to know?
Thanks,
Wayne

 

[Gordon Holsinger]

I've ordered a Weber conversion for my Series 5 Alpine. Are there any tips or tricks I need to know?
Thanks,
Wayne

Very sensitive to fuel pressure

 

[Wayne67vert]

Gordon, is it low from the factory pump?

 

[Tom H]

A few questions:
What manifold will you be using?
Any modes to the engine or is it pretty much stock 1725
Do you know what jets will be in it. Quite a few of us have had to experiment with different jetting.

Tom

 

[Wayne67vert]

I have ordered this kit: https://www.classiccarperformance.com/products/sunbeam-alpine-weber-carb-kit-32-36-dgv

Motor is stock as far as I know

 

[jdoclogan]

I've commented on the Weber conversion before. I put a 38-38 -DGV commonly used on Jeeps. You have to hone out the 32 inlet to 38 but no big deal. It will give you a bit more fuel thus an increase in HP. I use a Carter P4070 fuel pump supplying 4-8 psi and 50gph. Put a quality regulator in to dial in the best pressure.

 

[65beam]

These two cars use original series 4 intake manifolds with 32/36 DGV carbs. I've used the spacer that was original to the series 4 when fitted with the Solex PAIA carb. Using this original spacer allows you to use the carb without making any mods to the intake. They open full. These carbs were jetted by Doug for MGB's and since these are 1725's they work great. Over the years I've topped 30 MPG with the series 4. They both have original block mounted fuel pumps.

 

[Tom H]

I suspect it will be fine right off the bat, but since you asked :

Here's a thread with at least one experienced person's suggestion for jetting:

http://forum.sunbeamalpine.org/index.php?threads/weber-jets-and-valve-lash.27694/#post-192642

Might be worth a call to the supplier to ask exactly what jets are installed in the Weber they send you. If you do a search on Weber here you'll find a lot of discussion about jets for the 32/36 Weber.

 

[65beam]

The conversion to the Weber is without a doubt the best mod that can be done to the car. The green car has had the conversion since the mid 80's and the blue one was converted in 94.

 

[sunalp]

I have a 32/36 on my SV currently that uses the stock block mounted fuel pump, in fact I've
put Webers on a few other Alpines using the stock pump with no issues. Cars run great!

You will have to modify the throttle linkage. You can buy the rod from either SS or CS, but
you'll have to source a Series IV firewall bracket to make it all work. It's best if you can find
the whole SIV bracket & linkage.

Good luck!
Cheers!
Steve

 

[65beam]

I have a 32/36 on my SV currently that uses the stock block mounted fuel pump, in fact I've
put Webers on a few other Alpines using the stock pump with no issues. Cars run great!

You will have to modify the throttle linkage. You can buy the rod from either SS or CS, but
you'll have to source a Series IV firewall bracket to make it all work. It's best if you can find
the whole SIV bracket & linkage.

Good luck!
Cheers!
Steve

If the Weber is being installed on a series 5 the bracket for the Stromberg linkage can't be used. As mentioned earlier you need the series 3 or 4 firewall bracket. I had a local shop make a few of the fire wall brackets and the rod going to the carb. I had them make some changes to the 90 degree bend of the rod by making it longer so I can drill the end of the rod going to the carb for a cotter pin to secure the rod in the carb bracket. You can see this in my photo of the blue car.

 

[Wayne67vert]

Sounds like it might work out of the box or not.
What is the difference in the firewall brackets?

 

[sunalp]

You can barley see the bracket ( behind the brake master) in the picture of Bobs blue Series V. You can see the rod clearly
and see how straight it goes to the carb bracket. The stock Series V bracket doesn't put the rod in the correct location,
it sits too high. You want to make sure that you have a smooth operation with this or it will bind and stick the carb
either open or closed. It'll be hard to drive that way.

The Webers I've installed work pretty well right out of the box.
Cheers!
Steve

 

[65beam]

You can barley see the bracket ( behind the brake master) in the picture of Bobs blue Series V. You can see the rod clearly
and see how straight it goes to the carb bracket. The stock Series V bracket doesn't put the rod in the correct location,
it sits too high. You want to make sure that you have a smooth operation with this or it will bind and stick the carb
either open or closed. It'll be hard to drive that way.

The Webers I've installed work pretty well right out of the box.
Cheers!
Steve

I'll take a photo of the series 5 bracket and one of my reproduction series 4 brackets. The series 4 is stored in our garage about thirty miles from the house so I can't take a better photo of an original installed on the car but the series 5 is here at the house so I'll take a photo of the bracket installed.

 

[Tim R]

Wayne,
More important than the Weber carb is the inlet manifold. In my personal opinion after 37 years of Alpine ownership and multiple Alpines, fitting the twin choke Weber to the standard manifold will give you a good improvement over ANY other carb set up on an Alpine BUT the standard manifold tends to run rich on No 1 and No 4. Sometimes it is physically running with fuel on 1 & 4 and petrol drips out of the manifold drain pipe because of this. Fitting the Curved manifold as designed by the UK owners club with the forced induction system will prevent this problem and really release the power. You set the car up once and it just stays in tune, year after year with zero maintenance required. After Strombergs losing synchronisation or breaking their diaphragms, Twin Webers being a pain until the car is in the mid-range and Zeniths moving out of tune the twin choke Weber is a revelation.
Standard mechanical fuel pump is fine, no need to change it.

I would recommend making a new rod bracket with a phosphor bronze bush as shown in the video on The Sunbeam Alpine Channel on YouTube.

If you fit the new manifold do not connect the PCV valve to the threaded hole on No 4 or you will cause problems. Fit a blanking plug to that hole.

 

[Alpine 1789]

For a low buck bracket and rod, here are a couple of photos of what I did many years ago. I made the bracket with just some scrap sheet metal and a jigsaw, vice and hammer. As I recall, I made a cardboard template and wasn’t happy with my first bracket, so this is the second attempt. The rod was made with 1/4 bar stock and a piece of an angle bracket. I didn’t know how to weld at the time and brazed it with a MAPP gas torch. The whole setup won’t win any beauty prizes, but neither will my car. And it has served me well for about 20 years.

 

[65beam]

I just took photos of the brackets I had made a number of years ago for the conversion to a 32/36 on a series 5 alpine or earlier series with down draft zenith carbs. The bracket on the far right was on the blue car when it had side draft carbs. The bracket on the left is an original piece with the one in the center being one of the reproductions I had made. The dark linkage is an original from a series 4 with the Solex and the far left is a reproduction. The piece in front is a reproduction with the end turned 90 degrees to fit the Weber. I left the end longer so it could be cut to fit and drilled for a cotter pin. The rubber grommet is a piece available from most Sunbeam parts supplier that fits in the front opening of both the original and reproduction brackets. A small amount of lube preserves the piece. The reproduction bracket also has the opening in the top as original. I also included a well nut that I always use to mount the bracket. To use this requires drilling three holes in the fire wall.

 

[65beam]

didn't load

 

[Wayne67vert]

Thanks for the info and photos.
I now know what I need to do. I'm capable to make these parts and adapt them to my car.

Wayne

 

[Shannon Boal]

Tim, tell me about your cold air intake/air filter housing. It is the icing on the cake!
Shannon Boal

Wayne,
More important than the Weber carb is the inlet manifold. In my personal opinion after 37 years of Alpine ownership and multiple Alpines, fitting the twin choke Weber to the standard manifold will give you a good improvement over ANY other carb set up on an Alpine BUT the standard manifold tends to run rich on No 1 and No 4. Sometimes it is physically running with fuel on 1 & 4 and petrol drips out of the manifold drain pipe because of this. Fitting the Curved manifold as designed by the UK owners club with the forced induction system will prevent this problem and really release the power. You set the car up once and it just stays in tune, year after year with zero maintenance required. After Strombergs losing synchronisation or breaking their diaphragms, Twin Webers being a pain until the car is in the mid-range and Zeniths moving out of tune the twin choke Weber is a revelation.
Standard mechanical fuel pump is fine, no need to change it.

I would recommend making a new rod bracket with a phosphor bronze bush as shown in the video on The Sunbeam Alpine Channel on YouTube.

If you fit the new manifold do not connect the PCV valve to the threaded hole on No 4 or you will cause problems. Fit a blanking plug to that hole.

View attachment 18681 View attachment 18682 View attachment 18683 View attachment 18684