Author Topic: V8 electric pump  (Read 155 times)

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Farx4

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V8 electric pump
« on: August 25, 2017, 01:39:19 PM »
Need some advice please. Building a comp racer, standard V8 on an Edelbrucker carb, alloy tank in the rear tub and a 12v Bearmach fuel pump. Fuel line runs the most direct route that I can see out of the tub along the top of a chassis rail up onto the bulkhead and to the engine. At the moment it appears that the pump hasn't got enough pressure/power to lift the fuel the last bit into the carb. I'm thinking that I need a pump with a higher capacity, does that sound right? Thanks

Sandy M

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Re: V8 electric pump
« Reply #1 on: August 25, 2017, 04:13:17 PM »
Don't know much about the Bearmach pump you have, but when I had my 4.6 racer it ran quite happily with one of these..

http://www.gsparkplug.com/1x-facet-480532-red-top-cylindrical-fuel-pump-rtw506.html?gclid=EAIaIQobChMIwPePgNXy1QIV6rztCh1xsA7TEAQYASABEgIdx_D_BwE

Might be worth checking the specs of the Bearmach and the Facet for any major differences (assuming the pipes and filter(s) are clear and unobstructed).

Farx4

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Re: V8 electric pump
« Reply #2 on: August 25, 2017, 05:54:52 PM »
Thanks for the help Sandy, that is the kind of pump I had been looking at so it looks like I'm heading in the right direction.

Farx4

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Re: V8 electric pump
« Reply #3 on: August 25, 2017, 08:56:29 PM »
Sandy, can you remember if your racer had a fuel pressure regulator on the fuel system?

Sandy M

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Re: V8 electric pump
« Reply #4 on: August 25, 2017, 09:18:36 PM »
If I remember there was a restrictor fitted to the return line at the carb.

I honestly cannot remember how it was set up. Best ask Alastair (Valleyman) the new owner.

There are also two types of pump which look similar. One is meant to be low mounted and 'blow' fuel uphill to the carb, while the other is designed to be high mounted and 'suck' the fuel up to the carb.
Might be worth checking that what you have is suitablefor your set-up.

Another point is to consider the size of the fuel pipe. I would suggest a minimum of 8mm (3/8")  bore.

Farx4

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Re: V8 electric pump
« Reply #5 on: August 26, 2017, 08:49:10 PM »
All the stuff that I have read would point to the carb running at somewhere between 4-6psi which would mean a Silver top instead of a Red top which seemingly push out more pressure. 8mm bore as you suggest and a pressure regulator fitted somewhere along the fuel line. Think the crucial part has also been the height that the pump can push the fuel up to. Seems the Bearmach one that I have is to feeble in this respect but the Facet pumps are ok. Hopefully once all this is done the fooking thing will run properly  :)

Sandy M

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Re: V8 electric pump
« Reply #6 on: August 26, 2017, 10:26:51 PM »
well worth spending some time on the fuel system. After that all you need is clean air and a few volts at the right time and enjoy the Wubba Wubba RRRUUUUURRRRRHHHHHHHH!   :) 

cooltshirt

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Re: V8 electric pump
« Reply #7 on: August 27, 2017, 09:11:13 AM »
From my rally car days.
Facet pump, red top mounted at an angle, close to the tank. ...... not flat or vertical, that way they prime better. Bolt on with mini rubber exhaust mounts (or facets own) to stop frothing.
Then a filter king as close to the carb as practical so that the pressure set to on the filter king is what arrives at the carb, no losses on the length of the fuel line.
I used copper central heating 8mm microbore with a bit of 8mm flexi at the end.
That kept a pair a twin 40 DCOEs happy even on a hot day in Spain!
Good luck.
1983 110 V8. RIP

Farx4

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Re: V8 electric pump
« Reply #8 on: August 30, 2017, 04:10:49 PM »
Made some progress, plenty of fuel now getting to the engine and it will now run and make the noises that Sandy refers to. However it's still not good at  starting and won't idle properly so the next step is to investigate the timing for a V8 on an Edelbrock carb. Will start at standard settings and see how that goes also see if the pressure regulator makes any difference when it gets here.

Farx4

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Re: V8 electric pump
« Reply #9 on: September 06, 2017, 02:00:17 PM »
Fitted a Facet silver top pump, fuel pressure regulator and downsized the diameter of the fuel pipe. Engine starts first turn of the key and settles down to idle :D Now I  just need to fit the brakes, clutch pipe and get some propshafts made..........................