best location for electric fuel pump

[Andy8421]

In response to Alan and 2cams70, you are of course both correct.

In the case of the standard Elan, whether by design or by luck, the fuel pump is mounted under the carbs, which is about as good a place to have it as possible to minimise this effect.

I think I made the point that this effect was unlikely to be noticeable in a road car - the E Type has its fuel pump in the boot, and that doesn't seem to have held it back too badly.

For a competition car, there may be some merit in considering this problem. As I mentioned earlier in the thread, one contributor mentioned that there was a measurable change in fuel pressure at the carbs during braking and acceleration.

[Foxie]

I completely agree that acceleration/deceleration can change the pressure at the discharge end of the fuel line, depending on the length of the line, but the line is not discharging through a constant orifice, but through the open/closed position of the float valve. This would significantly remove the influence of any acceleration effect.

[512BB]

'That's harsh from someone who keeps his Sprint in one!'

Harsh. If giving 'sage' advise on keeping a car original is harsh, I shall continue to do so.

Someone mentioned on here a while ago that you can no longer express a personal opinion on here without the Woke Police poking their noses in, this being a case in point.

I must have missed where 'commentators' asked the OP why he wants to change to an electric pump? Why not deal with any problem that might exist, and keep the car as close to original as possible, before resorting to fitting an electric pump. I would think that 95% of old Lotus still run mechanical fuel pumps, from what I see at shows. They are incredibly reliable.

Leslie

[2cams70]

Think of it as being like an enlarged prostate. The main thing with something 50+ years old is to make sure the lines are clear. This is more important than the pump itself. If the original pump still works don’t tamper with it and consider it as something to cherish as an optional extra.

[Quart Meg Miles]

Leslie,

My stance on originality is well documented and it was the manner of your delivery of sagicity to an inexperienced member that prompted my ironic response. I endorse your message to not fit an electric pump without good reason.

I fitted one a few years ago as I believed the sudden onset of fuel vapourisation was due to alcohol in the petrol. Nobody else reported it so, as I had already driven 200,000 miles without one, I switched it off and am searching for other causes.

[Donels]

I'm about to fit a Huco pump in the engine bay with an inertia switch on my +2. What's the view on whether a solenoid is required or not?

Dave

[JonB]

A relay you mean? None needed.

[Donels]

Thanks Jon, I did mean relay.

[JonB]

And by the way, I fitted a Huco with inertia switch to my +2 because fuel evaporation from the Dellortos meant overcranking during cold starts was necessary to fill the bowls. It was a low pressure model designed to pull the fuel so I fitted it on the driver side inner wheel arch, close to the carbs, with an inline fuel filter.

I think this is a valid modification to make as the usage pattern of the car has changed since it was new. It’s no longer a daily driver, sitting unused in a garage for at least a week between successive starts. This gives plenty of opportunity for the float bowls to dry up.

Not the only mod I did, but all of them were reversible in case the car should fall into the hands of a purist. The car was sold on ages ago and I now have an S4 which I’m restoring. Hoping the Strombergs don’t suffer the same evaporation issues as the Dellortos and I can therefore stick with the mechanical pump.