Fuel regulator

[Aleco]

I'm working through replacing my SUs with Dellortos on my sprint.
Do I need to upgrade​ the fuel pump and/or fit a pressure regulator? Or is the standard pump man enough?

Thanks

Alex

[sprint95m]

It doesn't look like anyone is going to reply?



I have not fitted Dellortos myself so the following is just my opinion:

If it was me I would fit a regulator and also would consider fitting an electric pump.
I would do the latter if the electric pump is fully compatible with the biofuel (10% ethanol) now being sold.



Ian.

[killysprint]

My sprint has weber 45's, similar concept to your dellortos.

The std fuel pump won't cope with the demands of the carbs, especially on start up.

I fitted a facet silver top pump, an inline filter off a vw polo (a spare I had lying round) and a weber fuel regulator.
Set the regulator at '4' - haven't had a problem with over or under fuelling so never touched or adjusted it.

Hope this helps!

[soe8m]

A facet silver or gold top. A red top is a bit enthousiastic with a std engine and only webers or dellortos. The gold's I put on 2 liter cars, the silvers on 1300-1500 types.

The filter regulator you can use is a filterking. You can set the pressure with a pressure gauge to 0,3 bar. Then you have a simple bulletproof setup for your carbs.

Jeroen

[Aleco]

Brilliant thanks guys.

Just a few thoughts,

Where did you mount your pump? The manufacturers info says to mount it as close as possible to the tank but given the layout of the dolomite tank and discharge going immediately out the boot well and under the car this seems a little impractical. I was thinking as low as possible on the inner wing next to the carbs? This also makes getting an electrical feed easier to.

Cheers

Alex

[Mad Mart]

I'm using Weber 45s producing about 170-180 BHP at the flywheel. I used one of these Facet solid state pumps which does fine for the odd track day:-

https://www.merlinmotorsport.co.uk/p/fa ... -fac-ss500

Webers/Dellortos only need about 3psi.





Mounting is not pretty but it's up out of the way, only slightly above the tank...it's worked for the last 10+ years.

[soe8m]

The facet pumps are push types. They need to be at the same height or lower than the fuel tank. Also they need to be fitted in vertical position. In a lot of rally cars you see them fitted lying but then they don't work ok. A facet on the innerwing in the engine bay is a far from ideal position. The best is in the rear axle area. You can easily fit it in between the line and don't have the pump in the boot.

Jeroen

[Bumpa]

Webcon make a very nice pump designed for Weber and Dellorto carbs. It runs at the required low pressure and is very quiet in operation, unlike some Facet pumps which hammer away. I used the Webcon on my Elan with twin Weber and it was completely satisfactory.

[soe8m]

The facets that hammer are the angular ones like Martin has fitted. The round ones, bendix copies, don't.

In my experience the webcon ones are not that reliable and are pressure wise at the low side. The smallest facet has at minimum already over capacity and with a filterking the pressure will be constant. The webcons are at minimum to low for weber/dellorto and their maximum pressure is just enough.

The best is a pump with over capacity and regulate to have a constant pressure in all situations and l/h available than using a webcon one that is actually not suitable and pressure wise at the low side.

Jeroen

[shaunroche]

I'm using twin 45 Dell'ortos with a facet gold top pump in conjunction with a Malpassi Filter King mounted thus.....

[gmsclassics]

I've raced with one like this now for 15 years without issue. Feeding twin 45 Dellortos through two inline filters. Doesn't need a regulator and copes with flow for 7500rpm.
http://www.trademe.co.nz/motors/car-par ... 389935.htm

Mounted in the boot in the spare tyre well. Standard tank with a pipe running into the boot and then back out to standard fuel line through an inline filter with another just before the carbs. I do have a switch for this pump on the dash so I can switch the pump off if I need to.

Fairly basic setup, but then never had any issues with it whatsover and now up to 105 race meetings over 17 years.

Geoff

[Bumpa]

OK Jereon, I'll crawl away suitably chastised. The fact that a Webcon fed twin 40DCOE carbs on a Lotus Ford twin cam for all the time I had it counts for nothing. So sorry.

[soe8m]

OK Jereon, I'll crawl away suitably chastised. The fact that a Webcon fed twin 40DCOE carbs on a Lotus Ford twin cam for all the time I had it counts for nothing. So sorry.

In my experience......

I had this kind of discussion before a few months ago about a HUCO su pump replacement. Same size and and a direct replacement wit no need to alter anything. Also pressurewise ok for su's. One fb group member did reccommend one because he had one for years with no problems.

In the past i did fit about 40 of these HUCO ones and i think 35 came back leaking after a few months. Then i started fitting Facet ones with filterkings and these were ok. I think i fitted these combinations 300+ times over the years on all types of cars and none came back.

These webcon ones you have fitted are not webcon made and i think already many years on the market and i have seen these fail or in extreme situations cause fuel starvation. I think it's a US made pump because mainly found them on US imported cars.

That's my experience what i do share.

I'm not saying that it didn't work on your Lotus and it's for Aleco to choose.

I was for ten years a workshop manager at one of europe's biggest classic car companies which sold around 400 classic cars each year form 2cv to vintage ferraries and all in between. Together with the repairs i did see and test drive about 10 different classics a week. As the parts were ordered in large quantities there was time and financial room to experiment which parts are cheap and reliable. At one point after using various parts and seeing already fitted parts by p/o fail you know what to use. We had Bosch coils for breakfast for example. I had even a few classic oils tested in a lab which had a good amount of zddp and had the best oil in the bulk being tired of replacing camshafts. My experience with plugs. leads, coils, elektronic ignition conversions, fuel pumps or whatever "universal" parts are not from what i have just fitted on one dolomite but of using it many years on hundreds of cars.

So if the webcon pump does work for you i believe you but i hope i can express my opinion about these pumps also.

Jeroen

[Aleco]

Once again a great set of responses cheers guys.
However it's given me a few more questions!

Jeroen : If I've understood you correctly did you mount the pump external to the car in the rear axle well? I didn't realise they were rated for external use?

One for everyone: Where did you take your supply from to power your pumps? Did you fit an inertia cut out switch?

Alex

[soe8m]

Yes external. No vapours etc. The Facets do have an inbuild filter in the underside so no petrol in the boot while cleaning.

For electric pumps I use Ford relay's.

Original Hella's are harder to get, I buy them in Germany, but on ebay UK there are some alternatives.

Just use the hella partnumber and they show up. You must use the exact number as on the relay in the pic. The last few digits different does mean a totally different relay. This number is the only one with the normal 5 pin layout what does fit in any universal relay socket. You do connect the coil neg. to the relay. When ignition on it activates about 4 seconds and then shut's off. When the coil starts to spark the relay activates again. When the engine stalls the relay does also. In other words this relay is only activated when the engine is running, not constant when ignition is "on".

For extra safety an inertia switch can be added. Also on coil neg. When an accident happens, the coil is grounded, engine goes off and fuel pump goes off. Normally ignition positive is switched by the inertia switch but then you need an extra relay. As all modern inertia switches are change over you can also ground the coil. Most rallycars I do wire have it this way. When disconnecting the connector from the inertia switch the car does still run. Sometimes that is needed because of the bumps in special stages they can take the connector off.

Jeroen