Lotus Elan and Lotus Elan Plus 2 Forums

Hi Today I fitted one of these facet Type pumps bought on Amazon. Less than ?20 delivered so they seem good value

My original SU pump would stop when it reached pressure , this pump however keeps ticking albeit quietly , does anyone else have one of these and is this normal ?



Other than that , it seems fine.

thanks Steve

Looks similar to mine (but as mine's been in the car for decades who knows what model changes have come and gone). My one does tick slowly all the time though. Goes crazy to fill the float bowls up and ticks at about 2 per second after that.

Can't hear it after the engine starts though...

yes, this is normal : SU pumps have a point type regulation mechanism that stops the pump when the target pressure is reached, a bit like a compressor, while "solid state" after market alternatives just pump all the time (which also make them less expensive)

Steve,
I had the same puzzle and asked on here. Search for...How does a solid state petrol pump work...
Apparrently the piston has a deliberate leak past it which is a way of controlling the maximum pressure.
Mine was the lookylikey cube type and was ?12.50 on ebay.
Eric in Burnley
S3SE DHC (This message sent from my hospital bed following knee joint replacement. No driving and the sun is out here.)

A word of caution regarding these pumps, whether the tube type or the cube ones. They come in various pressure ratings. The Weber carbs like 2 0r 3 psi. Get too high pressure rating and you will flood the carbs and cause the float bowls to overflow and leak. FIRE HAZARD!

I will be installing a Facet cube type pump in my Elan, but only as a primer pump to prime the float bowls after the car sits for more than a a couple of weeks. In fact, I will power it though a momentary contact so it will only operate when the switch is held closed by hand. Normal fuel supply to the carbs will be through the normal mechanical pump.
Roger

Yes Roger, that is exactly what I did. If you look at my listing there are pictures of the installation, and I have a Filterking regulator fitted.
It takes maybe 5 seconds to prime the carburetters and then the engine starts without delay.
Eric

Interesting point about pressure , I do have a regulator fitted and it?s set on the minimum setting. I fitted this as the original P.O. fitted double su pump did cause fuel to seep back out of the carb trumpets.

I was wondering however if the regulators only reduce pressure when the fuel is actually flowing ? What happens when the engine isn?t running does the pressure equalise at around 8 psi which is what these pumps put out .

Steve

Elan45 wrote:A word of caution regarding these pumps, whether the tube type or the cube ones. They come in various pressure ratings. The Weber carbs like 2 0r 3 psi. Get too high pressure rating and you will flood the carbs and cause the float bowls to overflow and leak. FIRE HAZARD!

I will be installing a Facet cube type pump in my Elan, but only as a primer pump to prime the float bowls after the car sits for more than a a couple of weeks. In fact, I will power it though a momentary contact so it will only operate when the switch is held closed by hand. Normal fuel supply to the carbs will be through the normal mechanical pump.
Roger

Can you clarify, please.
If you fitted this in the boot, did you change the fuel pipe and connectors forward to the mechanical fuel pump to accomodate the new high pressure feed?
I assume the mechanical fuel pump will allow throughput of fuel, at pressure to the carbs, when it is dormant?
And likewise, the electric pump will allow fuel to be drawn through it by the mecahanical pump when it is not on?

Concrete-crusher wrote:I was wondering however if the regulators only reduce pressure when the fuel is actually flowing ? What happens when the engine isn?t running does the pressure equalise at around 8 psi which is what these pumps put out .

If you have the return type regulator, it operates at all times (it's like a faucet actuated by the excess pressure opening the return); if you have the blocking type regulator, in the event the blocking seal is weak the pressure would eventually equalize by fuel seeping pass it, but it should take some time and the actual flow would be a lot less than what would happen without.

In my case the electric pump is only energised for maybe five seconds when I pull the spring return switch under the dash and at this time the carb level is low and fuel is flowing through the regulator.
Also each pump seems capable of pushing or pulling fuel happily through the other.
If you read my other post, I guesstimated the resistance of the electric pump valves as less than 1 psi
Eric

In my case i replaced the old plastic pipe with 8mm knuffler or what ever it?s called , then finished with braided fuel line to the carbs. I don?t have the mechanical pump anymore.

I assume my regulator is the blocker type , it?s a small rotating dial in a chrome housing.

I think the pressure will equalise when there is no take off , so maybe it?s important not to have the pump running when the engine is not to avoid a risk of flooding the carbs.

My su pump looks a better bit of kit but probably no better in reality , I might try selling it and look for a low pressure version.

Steve

Concrete-crusher wrote:In my case i replaced the old plastic pipe with 8mm knuffler or what ever it?s called , then finished with braided fuel line to the carbs. I don?t have the mechanical pump anymore.

I assume my regulator is the blocker type , it?s a small rotating dial in a chrome housing.

I think the pressure will equalise when there is no take off , so maybe it?s important not to have the pump running when the engine is not to avoid a risk of flooding the carbs.

My su pump looks a better bit of kit but probably no better in reality , I might try selling it and look for a low pressure version.

Steve

if there is no return hose to send the excess fuel back to the tank it's a blocker type.

What you could also do is wire the pump so that it does not work when the engine is out (e.g. no oil pressure, via a relay maybe) and add a manual temporary bypass to prime the carbs if you need that regularly...

As noted, an advantage of these pumps is that they are inexpensive. In that range, they are designed for a specific output range and their design is intended to provide that range.

In practice, many seem to be above the optimum pressure for Webers. I would recommend, instead of buying different pumps in the vain hope of precision, that you invest in an inexpensive regulator instead and know that the system is safe.

Graeme,

The Facet pump will mount in the boot and there will be no separate regulator. Each pump will draw or push through the other. When I restored my Super Safety back in 1984-85, I replaced the plastic fuel line w/ copper tubing, and there is a rubber cushioned metal P clip fastened through the top of the frame to support the fuel line. I just cannot believe that anyone would knowingly flow flammable liquid through plastic tubing.
The momentary contact switch will be mounted in the boot also.

I would also replace the red plastic clutch line if someone actually made one for the Elan rather than hoping the one made for the Cortina would fit. That's why it has a "28" part number, but thats another story to go with the post from a week ago. I need to get Goodrich to start selling directly to me again, then I'll make a batch to sell to forum members that actually fit.

Roger

Hi all
A bit of a game changer here.
I now use a Pierburg pump.
Gotten Himmel! is it German on a British car.
Having used a Facet previously it drove me mad so I switched over to a Pierburg adding a regulator for pressure.
Much quieter a far less annoying.
Sadly though the price point is higher than the Facet.

Dave