Fuel Pump

[atallamcs]

Attention Alpine owners with webers--single or dual--I have a built 1725 in my Harrington with the webers tuned just right--it really does run well at most speeds. It seems to bog a bit a low rpms in town which I attribute to the stock fuel pump. I changed it out this week to the Carter pump that is always recommended, coupled with metal fuel lines and inline filter. Problem gone, car runs smooth at all speeds--really makes the car a daily driver without issues. This move is not only highly recommended but required to support the nature of a weber carb.

Bill Atalla

 

[Derek]

Bill, I am curious and would like to know more. I have an SV with a Weber 32/36 DGV, Crane X700 elec. ignition and a stock, though just rebuilt fuel pump. My car stumbles off idle, runs well through most of the range but has its moments espcially when cold. These mods were done by the PO , I've done the basics but think the jetting may be lean. Your comment on the nature of Webers and fuel pumps has me thinking.

thanks
Derek

 

[alpine_64]

I think that for a single DGV style progressive weber it may not be imperitive to go an electric pump, whereas a single or dual DCOE i think you should, or maybe the 38 DGAS. The stuble off idle on the DGV's was solved a little while back by someone on the board.. i believe a slightly larger pump jet may have been it, or perhaps idle jet?

 

[64beam]

My car stumbles off idle, runs well through most of the range but has its moments espcially when cold. These mods were done by the PO , I've done the basics but think the jetting may be lean. Your comment on the nature of Webers and fuel pumps has me thinking.

thanks
Derek

Hi Derek,

When cold, the Rootes engines did'nt idle that great as alot of period reviews have pointed out. As long as you can rule out everything else with the engine (perfectly tuned), then you could try some tinkering with your carburettor. The DGV idle jet are cheap, so it is a good starting point. As Michael pointed out, machanical pumps are more than capable with these carburettors, but an electric pump will also do a good job.

Regards, Robin.

 

[atallamcs]

Fuel pump location

For those who asked--I located the pump on the back of the battery box--there is space for the unit, easy to wire as the battery is right there--also, it complies with the recommendation to be placed within two feet of the fuel tank.
Bill

 

[Dr.NO 007]

fuel pump + elect battery

Safety concern ! ie: 1 bumpy road + sparks in the battery box + future fuel leak = instant BBQ
I am being a bit too conservative?

 

[napa 1]

Hey Bill. Glad to hear it is a success. How did the "custom" blanking plate work out?

 

[alpine_64]

Safety concern ! ie: 1 bumpy road + sparks in the battery box + future fuel leak = instant BBQ
I am being a bit too conservative?

You dont mount them in the battery box, you mount them on the outside of the box. Also if you do this (as i have) you should mount it using exhuast bobbins to stop it from making a hammering sound inside the cabbin.

 

[RootesRacer]

Attention Alpine owners with webers--single or dual--I have a built 1725 in my Harrington with the webers tuned just right--it really does run well at most speeds. It seems to bog a bit a low rpms in town which I attribute to the stock fuel pump. I changed it out this week to the Carter pump that is always recommended, coupled with metal fuel lines and inline filter. Problem gone, car runs smooth at all speeds--really makes the car a daily driver without issues. This move is not only highly recommended but required to support the nature of a weber carb.

Bill Atalla

IMO by changing from one pump to another, you have either increased or decreased the fuel pressure, which will affect the float bowl level.

If the engine runs better, then likely your issue (as most weber related tuning issues) relates to the emulsion tube choice, which is very sensitive to float bowl level.

 

[Nickodell]

Bill, I am curious and would like to know more. I have an SV with a Weber 32/36 DGV, Crane X700 elec. ignition and a stock, though just rebuilt fuel pump. My car stumbles off idle, runs well through most of the range but has its moments espcially when cold. These mods were done by the PO , I've done the basics but think the jetting may be lean. Your comment on the nature of Webers and fuel pumps has me thinking.

thanks
Derek

Try this thread: http://www.sunbeamalpine.org/forum/showthread.php?t=6828&highlight=Weber+DGV+stumble&page=2

 

[atallamcs]

This was my motivation for the upgrade suggested by the weber experts:

Fuel Pumps and Fuel Pressure:
Fuel delivery is critical to the proper performance of any Weber carb. From a basic 32/36 DGEV to a set of Triple Sidedraft DCOE's. Webers rely on a stable full float bowl in order to mix the fuel and air correctly. Mechanical pumps very rarely do this. They pulse fuel instead of giving a smooth even delivery and the amount of fuel varies with engine RPM.

A Proper Electric Fuel pump will give the best performance and most stable tuning for any Weber carb application. We use only High Volme and Low Pressure pumps. Webers work best at approx 4 psi of fuel pressure (Not 2 psi like many of the older books stated.) and you need Volume not Pressure to keep the float bowl full.

We ONLY use the Carter Rotary pumps. They are High Volume (60-70 GPH) but only 4 psi. This is PERFECT for all Weber applications from a Single 32/36 DGV on a Truck, Jeep or Car to a Triple Sidedraft setup on a Road Race car making 300 HP...This pump DOES NOT and SHOULD NOT use a Pressure Regulator for any reason. That is why we use it....

So, you decide.
Bill

 

[V_Mad]

I recently bought one of these carter electric pumps, and whilst testing it I was amazed at the high flow rate. Definitely no lack of flow with these! I think these are also well suited to Holley carbs too as the pressure is well within recommended limits. Be wary of some Facet pumps that have high pressure (8 psi etc) as you will need a regulator on those.

 

[Paul A]

We ONLY use the Carter Rotary pumps. They are High Volume (60-70 GPH) but only 4 psi. This is PERFECT for all Weber applications from a Single 32/36 DGV on a Truck, Jeep or Car to a Triple Sidedraft setup on a Road Race car making 300 HP...This pump DOES NOT and SHOULD NOT use a Pressure Regulator for any reason. That is why we use it....

So, you decide.
Bill

Hi all:

I also use the Carter pump with my Weber 32/36. I installed it at the recommendation of folks at Redline who are working with this carb on a regular basis. It's a bit noisy, but works flawlessly. www.redlineweber.com

 

[napa 1]

I'm also enjoying the benefits of this pump combined with the Weber 32/36. No stumble. Pump can be a little noisy when ignition switched on, but once engine is running, it's not heard from. On advice from the forum, I have a dash switch to turn pump off if igition is switched temporarily on without need of the pump. (electronic ignition).

 

[Bill Tubbs]

Carter for the Zenith Strombergs?

My 1725 has an electric pump (no name visible- mounted under the chassis) and I'm wondering how that Carter rotary works on a stock application? I may still go to the Weber configuration at some point but right now I'm about to install a pair of rebuilt ZS's on my stock mill and I may need to replace the existing pump if it's really a wild card in my system, i.e., I don't know the flow or pressure of it. I do know that the PO has a regulator installed and it's down to the lowest level because a mechanic indicated the pressure was way too high.