LagondaNet

[Lagondanet]

David Marks writes:

As for EFI:



I am a great fan, I don’t like carburettors and I really don’t get on with Webbers – the only good thing for me is the sound they make at full throttle.



I would expect a decent EFI system to improve fuel consumption by maybe 15% or so.



It is not practical to fit an original spec system to the earlier cars as basically the engine would require changing due to all the different castings.



So, the option is to fit an after-market system.



The control side could be supplied by any number of manufacturers, there is no real point going for a high end device such as Motec, the advantages are not worth the cost but something such as an Emerald system is a good starting base.



Installing it is not so much as difficult as technical – wiring harnesses need to be made and a fuel map programmed into the ECU, I would assume that a basic map would exist in order to start the car and then a few hours on a rolling road would refine this.



Perhaps the most tricky part is installing the recirculatory fuel system:



It is important (unless you get really fancy and use pulse width modulation to control a fuel pump designed for such an application) to have a return fuel line back to the petrol tank.



Later cars have this system, even on Webbers, certainly 13380 does, and it may have come in from there.



If such a system is in place, it is easy to break into the line in the boot, fit a pump suitable for an EFI system and a filter to match and just remove the in tank pump and original filter from under the car.



If no such system is installed, then the fuel tank requires removal for modification and this is a big job requiring removal of the rear seats to displace the rear A/C (if fitted).



In the engine bay, new throttle bodies are required to accommodate the injectors, there are probably units around that would replace the Webbers and bolt straight in but a more elegant way would be to use the inlet manifolds and other parts from an EFI Lagonda – if such parts could be found.



I reckon that a week solid should do the job, plus the rolling road work.



The draw back to EFI is peoples lack of understanding and the cost to fit – maybe £4-5000.00 as a wild guess for a half decent system but the advantage will (should) be greater performance, improved fuel consumption and better hot starting.



This is only as brief summary, I would like to do it to 13380 but don’t have the time now, maybe over the winter.



A good system can be made to fit well and look pretty too, installed badly, it will be a mess.

[Vincent]

And some additional information :

http://www.borla.com/products/induction/v8_kits/v8_kits-FR.html
_________________
Welcome to Paradise ! (FRONT 242)
https://www.youtube.com/watch?v=XS30BC3D5WM

[jonc]

David - it's because you are too used to SUs on the Jags

13287 has EFI fitted: http://lagondanet.com/bb/viewtopic.php?t=488

From the eBay listing: The internals are all new; and instead of the original webbers, the mechanic installed a fuel injection system, a new Motec 4800 fuel management system and a custom wiring harness.

Being a US emissions car, it has the box hiding the Webers, and so they can be (and were) replaced without altering the looks. This actually makes the system more like the Reeves-Calloway modifications for the engine designed for the Virage which has a large plenum containing the injectors and trumpets (and a Weber-Marelli EFI system).

Jonathan

[Vrije]

@ DAvid, 007 has twin fuel pipes !(feed and return) And is in process of having an efi LPG system fitted, also for added mileage/power.
Bonus on this lpg ecu is it has a second-option so can be used for petrol
too but thats for later '
Keep you informed.

Harry

[david]

Thanks for all this - the post Roger made was my reply to a mail he sent me as an enquiry from elsewhere.

Glad some of you at least think its' a good idea!

Jonathon, if only the Webbers were as easy to deal with and had the hot starting reliability of the SU's!!

I think that the whole induction system could be improved, there must be a lot of turbulence in the fairly shallow air box above the Webbers and the pulsing from the valve overlap will add to this, I assume.

Also the air intakes are not ideally placed, the air drawn in is partially heated by the radiator, especially at lower road speeds and on some cars, I see the air intakes pointing towards the radiator, this makes it even worse!

So, in an an ideal world, I would love to have the time to replace the whole system and use something along the lines of the standard EFI induction system as amongst other advantages, the twin thottle plates can be used which makes setting up the engine far easier.

I'm not looking for raw power, just an improvement in overall performance and hopefully the torque output at lower revs.

Still, finding time for all this is the big problem, so we'll see how much further I get but I'll look at all the references you've all posted - thanks, it'll add to my learning curve.

Maybe I'll practice on 13397 when that starts to go back togethether, as it is fairly well stripped out, it makes things slightly easier.

There seems to be no logic to the chassis numbers relating to the return fuel system fitted as standard.

David

[jonc]

Yes, I agree the airbox is a compromise. I think it is like that because of bonnet clearance. A flat plate on top of the carbs (with no trumpets or 'stub stacks') will result in restricted airflow at the carb's venturi mouth, but I think only the Vantage engined V8s had them. I think they did have a taller inlet manifold, but certainly a taller air box, as did all the rest of the V8s, with the possible exception of the V8 Zagato Volante in non-vantage form, which didn't have the bonnet bulge.

I am not knocking the SUs - my Silver Spirit has them and I am impressed that a pair of 1 3/4 inch carbs supply a 200bhp engine so well. And I agree about their hot starting which is excellent on the Spirit. One reason about them being easier to set up though is that there aren't usually eight of them on an engine!

On my red Lagonda, I replaced the rubber seal at the scuttle with a shorter one which leaves an air gap between the scuttle and bonnet - that's my solution to hot starting. The bonnet is usually well-sealed which must make it pretty hot in there when the car is standing after a run. The stuff I used is here: http://www.cbsonline.co.uk/product/Boot_%26_Door_Seal_Small_TRMBS