Fuel pump suggestions l28 2" Jag carbs BAR needles

[zedhed]

Hello got a question for you all,

I re-fitted the facet #480532 pump my car came with:
http://www.glencoeltd.co.uk/facet-480532-red-top-cylindrical-fuel-pump/
Maximum fuel delivery 45 gallons per hour. Maximum pressure 6 to 8 psi

However it's way too much pressure and overwhelms the carb bowls with petrol dripping out of the carbs onto the manifold (didn't detect this before, because the float valves were seized

(that'll teach me to clean and service the carbs but hey, they had been bodged beyond recognition, filed needles, the works)

Anyway got suggestions? Flow rate psi?

Was thinking this might work:
https://www.pegasusautoracing.com/productdetails.asp?RecID=2698
Maximum pressure 2.75-4.0 psi. Maximum flow 34 gallons per hour.
#477060

I'm not sure what kind of pressure and flow rate I should be looking at, nor why there's such variation on the spec, from 2.75 to 4 seems a lot.

If it helps engine is an L28 with suspected cam by a "Richard Wardle" or at least that's what the plaque on the rocker cover says. I have to say this thing revs like hell, but no wonder it was running so darn rich

S'cuse learning curve, I make telescopes so have some engineering knowledge but I know next to nothing about cars

Cheers guys, Nick

 

[datsfun]

I would fit a pressure regulator to lower the pressure to desired flow rate. There was a good thread on here in last fortnight about fuel pressure etc.

 

[zedhed]

Can't see that thread in the last 2 weeks maybe moved?

PS: I have the fuel rail with return feed but that feed doesn't come out of the float bowl overflow, it comes out of the fuel rail block thingy closest to the cockpit, that sound correct?

 

[datsfun]

http://zclub.net/forum/showthread.php?t=23653

 

[Mr.F]

Filter King fuel pressure regulator and built in filter ideal for this application...also with option to fit pressure gauge.

 

[zedhed]

Hello chaps thanks for suggestions, from the other thread I need 2-3.5 psi and some way of adjusting it accurately. I forgot to say there is a filter king as shown by Mike installed already but it looks very old and isn't doing it's job so going to take it apart and have a look. They probably have a diaphragm / spring arrangement which degrades over time...

Another thing which strikes me is that this stuff probably shouldn't be in the engine bay and that its all mounted too high up on the front inner right, also that these pumps seem to pulse a lot when you really should have constant flow... Am I right or wrong?

Bloody tank sender isn't working either so any tips on testing that would be appreciated when I get there (it looked ok but removed it when I reconditioned the tank)

Thanks guys always appreciate guidance sorry for all these newbie Q's

N

 

[zedhed]

Oh yeah is there such a thing as an accurate fuel pressure gauge? Internet reviews suggest the cheap ones are ****

N

 

[Mr.F]

Facet pump is a better pusher than a puller and should be near the tank at the rear.
Filter King is OK in the engine bay and this would also make filter changing easier...

is there such a thing as an accurate fuel pressure gauge?

Shall we go with fuel pressure indicator then?

 

[Alphabettispaghetti]

You can get the filter king with a nice glass bowl which would look right too I think. The filter king say that the gauge shouldn't stay connected but I can't see what the major issue would be. I guess vibration will kill it after a while but they're not too expensive to replace.

There's some nice fuel lab ones on sale on ebay at the minute from DT in their clearance listings.

 

[racer]

As Mike says. My Red top is mounted by the tank and the regulator/filter is in the bay. Had this set up for 10 plus years(same pump) works perfectly.

 

[bigblock]

As mentioned regarding leaving fuel gauges in engine bays(theres always the isolator option plus also required in some racing regs)connected you could argue the safety aspect of the bourdon tube rupturing/fatigueing inside the gauge theyre usually brass attached with solder.Although you can get them made of stainless and more fatigue resistant materials for industrial use usually.And if anyone is interested in accuracy of wet gauges heres a link(go down to direct mount 1 1/2 gauges) Marshalls supply aeromotive and holley 1 1/2" fuel pressure gauges from what i remember.
http://www.marshallinstruments.com/FAQs/index.cfm

 

[zedhed]

Thanks guys, I need a temporary gauge just to check and then remove, but wouldnt leave it in there it would just get shaken up and unsafe as you say.

I guess mounting the pump inside the car at the back is the way to go.

where's a good accessible spot without buggering up the trim and original look of the car? Please send pics if you can be bothered

Cheers for all the input good forum this!

N

 

[zedhed]

Ok chaps here's some pictures I took showing my setup

http://zclub.net/forum/album.php?albumid=125

I adjusted the Malpassi filter king to lowest setting and the carbs still flood, you can see the flow in the pictures, and also how far I unscrewed the regulator diaphragm spring compression screw. I ran out of thread... No luck, it could fill a petrol can in about a minute, I guess this pump is probably too powerful for the regulator to handle or the regulator is faulty.

Possibly switch to a Sitech one or just get a pump designed for carbs which will cost the same

 

[morbias]

Are you sure your regulator is on the feed and not the return? If it's on the return then you need to adjust it the other way.

 

[jonbills]

Needle valves in the carbs could also be knackered. I'd strip them out before investing money in new bits.

 

[Rob Gaskin]

Are you sure your regulator is on the feed and not the return? If it's on the return then you need to adjust it the other way.

Needle valves in the carbs could also be knackered. I'd strip them out before investing money in new bits.

Both valid points. Also you are not testing the pressure just the flow rate. When you flush a toilet you get a bucket-full of water in a short time but little pressure.

 

[zedhed]

Well, after the pump, it goes into the metal fuel pipe assembly which goes around the rocker cover to the carbs. There are two parts to this pipe work, terminating in a "block" with an exit pipe. I'm pretty sure its the same way it was, but I'd better check - which part of that rail is feed and which is return, is it the top or bottom metal pipe?

(yes I replaced the jets, needles and valves plus float bowl valves, which is how these leak problems came to light)

(Hi Rob, yep got a pressure guage on the way but seeing the regulator makes no difference to the "distance" travelled by the fuel stream in my admittedly unscientific squirt-test, I suspect it's just too high, hence question about connections, more pics coming up!)

 

[zedhed]

Ok here's photos showing the entire fuel system at the front, the facet fuel pump out flow is at the top

http://zclub.net/forum/album.php?albumid=125&pictureid=1161

Please comment on the connections do you think they're right or wrong, could be improved?

 

[zedhed]

Excuse photo upside down tried flipping it in iPhone but i think forum image compression software doesn't recognise iPhone orientation tag still you can trace the whole system from one photo

The outflow from regulator and pump goes into the lower of the two factory metal fuel pipes

The upper (overflow?) pipe goes back to the tank via a brass tube

The upper and lower tubes are separated by a block thingy which might just be a mounting point or may even have a valve inside it, not sure what's in there and can't find any info on it online

 

[Rob Gaskin]

Zedhead, you can't measure pressure unless you block-off the end of the pipe.