Twin SU plumbing and throttle

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satancom
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Twin SU plumbing and throttle

Post by satancom »

Morning all,

I have fitted twin SU's to my V8 and am trying to sort out the plumbing and throttle.

Pipework
======

Each carb has a rocker cover breather which is simple. Each carb also has a fuel line at the top of the carb and what apears to be some sort of balancer pipework (which is missing) at the bottom for the fuel? It has some scrw fixings. There is also a very small vacume pipe on the left bank carb.

Can ayone shed some more light on this set up, a picture would be great :)

Throttle
=====

I removed twin strombergs from the engine and had some throttle linkages for them. The rod that connects the two strombergs is a tad short for the SU's, where can I get a new one? Also has anyone got any pictures of the throttle set up as I need to mate it to my series land rover throtle set up.

Cheers



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ChrisJC
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Post by ChrisJC »

Burlen Fuel Systems do the little linkages & things.

On an SU, the pipes sticking up at about 45deg from the upper part of the carb (but below the dashpot) are fuel overflows, and are normally just piped forwards and down.

The fuel inlet pipes are threaded.

Chris.
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satancom
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Post by satancom »

Ok so the top ones are the overflow, ok thats cool. Should they return to the fuel tank or just to the ground? :?

Do you know what the fittings are as I can pop along to somewhere like pirtek and at leats look like i know what im talking about :)

Found the Burlen Site, will nose around there.

Cheers

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Post by ChrisJC »

The overflow should just go to ground. They only get used if the float valves fail.

Don't know what size the fuel fittings are.

Chris.
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Post by RoverP6B »

As Chris indicated, the float chamber vent pipes must each be fitted with a hose which is then brought forward and down to hang beneath the engine in clear air. Fuel vapours will exit via these hoses, and should a float fail and sink resulting in an overflow, the fuel is then dumped onto the road and away from the hot engine where a fire might otherwise result.

The SU carbs that you have, I assume are of the HIF6 type?

Each of the fuel entry lines (one per carb) with nut and olive are connected as such....

The LH (dip stick side of engine) accepts a line via a fuel filter. A "T" intersection just prior to carb entry directs fuel across to the RH carb. A spill return comes off the RH fuel entry and directs excess fuel back to the tank.

Ron.
4.6 Rover 3500 P6B

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satancom
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Post by satancom »

Great infor thank you. With regards to the overflows/vents. This vehicle will be used for wading, is there any risk of water being sucked up the overflow? If so i will vent them somewhere out of harms way!

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Post by RoverP6B »

Certainly with the HIF6 carburettors, suction does not occur through the float chamber vent pipes.

They just vent fumes to atmosphere, and should a float fail and sink, direct fuel while the engine is running onto the road. In cases such as this, the flow of fuel onto the road is quite considerable.

Ron.
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Post by Pocket rocket »

Hope these pictures help (engine as it came to me)
Image

[/img]Image

Image

[/img]Image

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Post by Pocket rocket »

Another if it helps

Image[/img]

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Post by RoverP6B »

Pocket rocket very kindly posted picks of his engine, which to my eye features HS44 carburettors. The linkage arrangement is different to those on the HIF6 carbs.

The fuel line linking the two carburettors is the same, although without the spill return feature.

Ron.
4.6 Rover 3500 P6B

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Post by RoverP6B »

Ooops, that should be HIF44 :oops:

Ron.
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satancom
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Post by satancom »

Great pictures, thanking you :)

Those carbs and the throttle linkages look the same as my set up. I have 'Made' the tromberg setup fit after a fasion. Looks nothing like that though, which is probbaly a bad thing. Thankfully i have a spare set of carbs so if it doesn't work I can just swap the original Linkages back over :)

CHeers folks, this will help a lot!

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Post by Pocket rocket »

Thanks for the info, Ron.

TBH I wasn't sure which carbs they were :oops: , so you've saved me a few hours research.

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Post by satancom »

Well I have my fuel pump all connected up and working now :)

One question. The fuel inlet on the carb. Currently it has a mistery fitting on. The pipe under the fitting has a ridge as a normal push fit system would. Can I just dremel the screw fitting off, push a hose over and use a small jubilee clip to hold it in place?

The reason I has is I have loads of clips and none of these fittings, and don't really know where to get them anyhow? Surely this would be the same and secure ? The pump is only 4psi so shouldn't blow the jubilee clips off!

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Post by ChrisJC »

Yes. I did that too.

Chris.
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R/R P38 4.6 V8
R/R L405 4.4 SDV8

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