Fuel overflow pipes

[JeffW]

Does anyone have a picture where the fuel overflow pipe from the Strombergs attaches at the carbs? I know where the clip at the front of the engine goes (PCR 411), but the parts diagram shows a second clip PCR809 needed, but unhelpfully the diagram is very vague as to its location. I can't find any photos showing where it attaches.

Thanks
Jeff

GRID005207 NEW.jpg

[MandM]

I have my pipes like this, I did at one time have the overflow pipe on the offside go over the top with a P clip on the top carb to elbow bolt, but this as others have said just looks wrong as the fuel has to go up and over.
1000001718.jpg hope that helps

[JeffW]

I have my pipes like this, I did at one time have the overflow pipe on the offside go over the top with a P clip on the top carb to elbow bolt, but this as others have said just looks wrong as the fuel has to go up and over.
1000001718.jpg hope that helps

Thanks - does this mean you don't use clip PCR809?

Jeff

[MandM]

correct, this was the other way
P1090894.jpg as you can see it's just not right, but that was how mine was when the car was purchased

[JeffW]

Oh I see what you mean and yeah, that's just wrong. I wonder where they intended the clip to go?

Thanks for the help, much appreciated.

Jeff

[APS]

It does make complete sense for the pipe to go under the offside carb.
I have tried this but I always could not get it to route under the carb without it fouling the accelerator cable.
Looking at stags for sale and pictures of their engine compartments and mostly this pipe goes over the top just as I have had to do. P clip on the middle upper elbow bolt hole.
Only way I can see to avoid the accelerator cable was if the pipe was somewhat longer before it bends underneath. Or is my accelerator cable in wrong place ? if so it would seem I am not the only one.

[SteveD]

This is my layout. I agree it doesn't look right.

[richardthestag]

Strictly speaking they are float chamber vent pipes and not petrol overflow. Mind you at least the carb doesn't overflow into the inlet manifold.

For the factory install where the RH carb pipe goes over the top of the air filter elbow, the p clip is secured to the short elbow bolt IIRC.

When you route the pipe under the air filter elbow there is no clip needed, t-piece sits under the airbox and the breather pipe is strapped to the timing chain cover such that the end of the pipe is directly below the engine. Just like in MandM's photo

[Lingen]

Richard.
Doesn't it?? I have seen many inlet manifolds with a pool of fuel in them. I think those pipes need to be routed as low as possible to reduce the risk.
Mike.

[richardthestag]

Richard.
Doesn't it?? I have seen many inlet manifolds with a pool of fuel in them. I think those pipes need to be routed as low as possible to reduce the risk.
Mike.

From my experience and understanding, though happy to be corrected and further expand my knowledge.

No where near as much as some fixed jet carbs, the pool of fuel will be down to incorrect setup of the carb, the only exit point on the stromberg carb that might flood the inlet, provided that the cold start / choke is closed will be the main jet hole. The needle restricts that unless the throttle is wide open with the engine running at some revs. If the carb is going to flood then the fuel will like any liquid find the path of least resistance. this is the float chamber breather pipework.

If the carb floods whilst the engine is flooding then the engine will be very lumpy and most likely stall. Giving fair warning to an issue.

The pipe is rerouted on the RH carb to prevent the risk of the air filter being flooded as I understand

I have seen both Rover v8 and Stag v8 flood from the breather whilst the engine was running. With both Stromberg CD and SU HIF (on the Rover v8)

In every case that I have encountered the root cause was poor float height setting, poor quality needle valve, poor filtering of fuel into the carburettors but most frequently fuel pump pressure has been too high. On one Range Rover / Rover v8 setup this was because the 1/4" return to the fuel tank was damaged and restricting the return flow. As the stag doesn't have a return pipe regulating the fuel pressure is essential to good service and running.

Fixed jet carbs are also sensitive to fuel pressure, poor float setup etc etc etc, however my understanding and experience is that they flood through the throttle butterfly and directly into the inlet.

[DJT]

The vent pipes on mine run as originally intended, and have done for many, many years. Although I can understand the argument for change, it has never been an issue. This photo was taken during first start up after the engine rebuild last year.

IMG_0824.jpg

[Lingen]

Richard.
Good to see a properly plumbed in header tank! I agree that flooding would only occur from the main jet if there was a fault somewhere, like for instance, a restriction in the breather system. If the R/H float chamber was flooding, and having to push the fuel up a breather pipe like the one in the picture, I think it might take the easier route in to the manifold. It could perhaps also divert in to the nylon pipe to the back of the air box if it was raised like that.
Mike.

[DJT]

Richard.
Good to see a properly plumbed in header tank! I agree that flooding would only occur from the main jet if there was a fault somewhere, like for instance, a restriction in the breather system. If the R/H float chamber was flooding, and having to push the fuel up a breather pipe like the one in the picture, I think it might take the easier route in to the manifold. It could perhaps also divert in to the nylon pipe to the back of the air box if it was raised like that.
Mike.

Mike,

I take your point, but (and this is tempting fate) in 34 years, 115,000 miles I have never suffered from flooding carbs. The carbs in my picture have Grose valves fitted as I do not trust the original type offered by the usual suppliers.

Dave

[JeffW]

Thanks all, when the clip comes I will see how it all lines up and turf it and re-route under the carbs if it looks wrong.

The only time I have had fuel spill out was due to blasting material being left in the bowls thereby jamming the valves.

Jeff

[jbuckl]

Strictly speaking they are float chamber vent pipes and not petrol overflow. Mind you at least the carb doesn't overflow into the inlet manifold.

For the factory install where the RH carb pipe goes over the top of the air filter elbow, the p clip is secured to the short elbow bolt IIRC.

When you route the pipe under the air filter elbow there is no clip needed, t-piece sits under the airbox and the breather pipe is strapped to the timing chain cover such that the end of the pipe is directly below the engine. Just like in MandM's photo

Afaiaa the vent and overflow pipes are separate items.
The o.p. Was asking about overflow pipes.

The overflow pipes are perhaps an acknowledgement that strombergs on the stag are installed at a jaunty angle…. Above the recommended angle (perhaps)

The float chamber definitely wasn’t originally designed to be installed at the angle it is in a stag.

There… I’ve said it!