7 replies to this topic

[86mayfair]

Hi folks

 

I'm looking to fit a facet solid state fuel pump like this one: 

 

http://www.med-engin...p-kit-fast-road

 

And I was wondering if it is necessary to use a fuel flow regulator, or a relay, or a filter after the pump (which seems slightly pointless)

 

Is it worth buying this kit instead?

 

http://www.med-engin...ast-road-inline

 

[dklawson]

First, why are you buying a new pump?  The stock pumps can easily keep up with the demands of all but full race engines.

 

If you really need a new fuel pump, consider buying the pump shown in the first link.  I do not use the filters that come with the pumps.  I place a coarse, transparent, inline filter before the pump to protect the pump's valves and I place a fine, translucent, disposable filter right before the carbs to catch anything that gets through the pump.

 

If you buy the pump in the first link, you should not need the regulator.  The listing says that the MED pumps are selected to be compatible with SUs.  If you bought the kit in the second link, the flat, round, pancake regulator that is supplied has a reputation for poor performance and failure.  There are better regulators available.

 

I am not trying to throw any stones at MED but you can probably buy a comparable Facet pump from any number of suppliers for less.  The key part is buying a low pressure model.  SUs prefer about 2.5 PSI and you really don't want to supply them more than 3.5 PSI unless you add a pressure regulator.

 

Relays and safety interlocks are optional but generally a good idea.  The relay will protect the switch contacts in the car's "regular" wiring.  Interlocks such as inertia switches will protect you in the event of an accident.

[nicklouse]

The first link will be fine unless up the pressure generated is to high where it will then flood the carbs.

But if the carb is only just providing the right pressure then you can have fueling issues.

Which is why on a hot engine I would run a pump with greater capacity and then run a regulator close to the carb.

Running a pressure regulator with a large filter bowl can also have further advantages.

[86mayfair]

Ok, thanks for the insight guys :)

[Cooperman]

I run a pair of those in parallel. They are mounted inside the rear sub-frame bolted to the rear seat base panel. Each has the screw-in filter and are able to be individually switched.

I have a pressure regulator set to 3.5 just before the twin H4 carbs. It works well and should one pump fail the car will still run perfectly.

[86mayfair]

Yeah that certainly makes sense for a competition car Peter! These days with control modules if one pump fails it can switch automatically without the driver even noticing a thing!

 

Thanks for the comments guys, I went for a "road" pump kit with the screw on filter but didn't bother with a reg in the end. I think I'll be mounting it on the LH side of the subframe on the vertical part in front of the cut out for the trumpet/hi-lo. at the 45 degree angle recommended. I may also bend a bit of steel or ally - whichever I find first - to make a shield for it 

[dklawson]

I think you will be happy with your selection.  Keep us up to date with your progress.

[86mayfair]

Will do! The general stage of my build at the moment is "electrics" so today I converted my loom (much soldering and fitting of bullet connectors) and fitted the old 3 clock centre dash and loomed it all up, them for a fairly quick job I went around all of the front suspension and subframe bolt checking and adding Torque-Seal. I expect that my next job will be to fit the fuel pump and connect it all up