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Triple Weber Carbs - Pump, Filter & Pressure Regulator advice?


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When my current TR5 restoration is complete I will be running it on triple Weber 40DCOE carbs on a Cannon manifold.

Can anyone advise on pump, filter and pressure regulator types, positions and fixings please. I have some ideas, as below, but am open to other's views. Photos of successful installations would be appreciated.

I had envisaged using the original standard TR5/6 filter fixed in it's original position and fed from the tank as original.

I intend to use a Facet Gold Flo pump but am not sure where is the best location for it. Does a Facet pump work if fitted horizontally or does it have to be vertical? If it will function horizontally, it will fit in the location where the original PI PRV was fitted. I can make a mounting plate using the 2 fixing holes in the body where the PI PRV was fixed. Alternatively, I could make a mounting plate using the 3 holes in the inner wheel arch where the original PI Lucas pump was fixed but the direction of the inlet and outlet pipes may be difficult to hide behind the boot backboard trim here.

I have considered a Fuel King Regulator/Filter as per link https://fastroadcars.co.uk/store/index.php?route=product/product&product_id=107&search=Fuel+King . I assume this is best located in engine bay but not sure where.

Any ideas or advise on any of the 3 items gratefully received. 

Dave McD

 

 

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I use the standard mechanical pump that the Stromberg's use, no regulator. I know I am not the only one. The only issue I have that is when the car sits for several days it takes a while to fill the float bowls. If I do go electric I'll fit a pump likely on the frame just below the tank. The electric pumps are generally designed to be gravity fed and act as pushers not pullers. The pump you are looking at has a low end of 2.5 psi which is about the max that you need so I would look at a pump with a lower operating range and similar for the regulator. You dont really want to rely on it working well at either upper or lower limit.

Stan

 

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140,000 blissful miles on my Webered '250s using the OE AC type mechanical fuel pumps since 1996. Top speed I've done is 115 mph ( briefly ) but it was still accelerating and I don't know how it would do beyond that. Racers contend they won't keep up; I don't know why they wouldn't unless they might start to float at 3000+ cpm ( 6000 rpm ). I don't run mine much past 5500, ever. Pic below is engine with ~ 170 BHP - not dyno'd but has ~ 11:1 c/r, 1/2"  lift cam w/292 deg duration, 32mm chokes.

Congratulations on your choice, Dave. Once set up you'll never look back!

 

Tom

 

IMA 68 TR ALBUM COMPLETE 018.jpg

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55 minutes ago, foster461 said:

The only issue I have that is when the car sits for several days it takes a while to fill the float bowls.

 

Quite true; I've never minded opening the bonnet before driving to ogle the works ( and prime the carbs ). If it hasn't been more than a couple of days I may not do so.

I reckon an airbox would address the issue, extending the dryout time by many days.

 

Tom

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14 hours ago, ntc said:

Dave

Wrong pump wrong filter also regulator and not in the right place :ph34r:

Neil,

Thank you for your usual concise, insightful comments, really helpful.

Stan and Tom,

Thanks very much for that. I hadn't really considered a mechanical pump without a regulator. Glad I asked. Do you use the standard filter in the boot?

My initial ideas were based around the set up that I have in my race TR6 with triple 45DCOEs. That has a Facet Red Top pump, barrel type filter in the boot and Fuel King Regulator in the engine bay but aesthetics and boot space were not a consideration there. With a steel billet crank, Carillo rods, forged pistons, etc, etc the car revs to 7200 rpm and develops 240 bhp.

Any further observations will be welcome from anyone.

Dave McD

 

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Dave (and others),

why would you need a pressure regulator on a carburettor, if the pump maximum head is lower than the closing pressure of the float needle valve? I bever had one fitted to any of the carburettor engines I had.

A SU membrane pump could be an option too, contactless off course.

Cheers,

Waldi

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6 minutes ago, Dave McDonald said:

Do you use the standard filter in the boot?

 

 

Dave,

Mine have the AC type filter in the original TR250/TR6 carb position; just upstream of the pump ( below, actually ), 5/16" line. With the filter in the pump itself and the screen in the Webers that makes (3) in all. Nothing can get through that would clog any of the carb orifices.

 

Tom

IMA 68 TR ALBUM COMPLETE 019.jpg

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12 hours ago, TorontoTim said:

Neil - could you be a little bit more of a problem solver rather than just a problem finder?

 

Before you all jump to the wrong impression , I am busy doing other things just now I have contacted Dave and will help him.The part numbers have changed also spec. Waldi you do need a regulator. 

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If you are using an electric pump I would install a Malpassi Filter King. They incorporate both a filter and a pressure regulator. They can also be fitted with  a gauge.

I had one on a duel DCOE carb'd Alfa with an electric pump and it worked  great.

Here is a link to a suitable one. https://www.ricambicarburatori.com/contents/en-us/p1425_Malpassi_Filter_King_Fuel_Filter_and_Pressure_Regulator_85mm_-_Clear_Glass_Bowl.html

I have not dealt with this firm, just posting it as a "fer instance".

t_fk85_filter_king_85_mm_competition_fuel_filter_pressure_regulator_glass_bowl_clear_ds.jpg

Edited by Andy303
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If you have the standard pump (it is a USA spec car you are converting to triple Webers i presume) it would seem a sound starting point - if when you do a rolling road set up, you find it is running out of fuel at high revs & WOT then might be the time to put an electric pump on.

With may of the electric pumps you may need a regulator - which is what your post was about, however I was going to toss another option into the reconing: could a Stag fuel pump(think the TR8 uses the same) be used? Pump a decent volume at carb pressures and self regulate.

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My 3.8 S XK was fed through 1 single SU pump (2nd redundant installed but switched off. It was large enough, even at top speed. No pressure regulator.

Waldi

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1 hour ago, Waldi said:

My 3.8 S XK was fed through 1 single SU pump (2nd redundant installed but switched off. It was large enough, even at top speed. No pressure regulator.

Waldi

Hi Waldi

Su or stromberg  dad had a 3.8 s type :D the carbs have different requirements from Webers.

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5 hours ago, Waldi said:

Dave (and others),

why would you need a pressure regulator on a carburettor, if the pump maximum head is lower than the closing pressure of the float needle valve? I bever had one fitted to any of the carburettor engines I had.

A SU membrane pump could be an option too, contactless off course.

Cheers,

Waldi

Hi Waldi,

The Facet Gold Flo pump (which I already have, so hence the desire to make use if it on a purely economical basis) has an output from 2.5 - 8 psi so hence the need for a regulator to bring it down to a constant pressure which I understand needs to be around 2.5 - 3 psi.

Dave

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4 hours ago, ntc said:

Before you all jump to the wrong impression , I am busy doing other things just now I have contacted Dave and will help him.The part numbers have changed also spec. Waldi you do need a regulator. 

All, I can confirm that Neil and I have exchanged texts about equipment and he will forward his ideas over the weekend.

Dave

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3 hours ago, Andy303 said:

If you are using an electric pump I would install a Malpassi Filter King. They incorporate both a filter and a pressure regulator. They can also be fitted with  a gauge.

I had one on a duel DCOE carb'd Alfa with an electric pump and it worked  great.

Here is a link to a suitable one. https://www.ricambicarburatori.com/contents/en-us/p1425_Malpassi_Filter_King_Fuel_Filter_and_Pressure_Regulator_85mm_-_Clear_Glass_Bowl.html

I have not dealt with this firm, just posting it as a "fer instance".

t_fk85_filter_king_85_mm_competition_fuel_filter_pressure_regulator_glass_bowl_clear_ds.jpg

Hi Andy,

That is exactly the Regulator that I mentioned in the link in my original post, except I showed the Alloy bowl instead of the glass bowl. It has both a filter and a pressure adjustment facility. I fitted one on my race TR6 with a pressure gauge which was used at the rolling road when the Webers were set up for maximum performance.

Dave 

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5 hours ago, foster461 said:

I use a standard plastic in-line fuel filter that is inserted into the rubber fuel line just before the pump.

Stan

Hi Stan,

I originally had this Sytec type of filter in mind, purely because that's what I have fitted to the race TR6. https://www.demon-tweeks.com/uk/sytec-high-flow-motorsport-fuel-filter-2010167/

On the race TR6 it's fitted between the tank and the Facet Red Top pump.

Dave 

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2 hours ago, stuart said:

Usual regulator fitment is one of these Regulators mounted flat on top of the right hand footwell

Filter is this one Filter

Hi Stuart, I hope all's well with you in deepest Cornwall. We're in Tier 3 Covid precautions in Nottinghamshire from tomorrow.

I've also got one of those Sytec regulators but it looks a bit Mickey Mouse and has no facility to monitor the actual pressure being delivered.

The Facet filter that you've shown is similar to the Sytec unit that I've mentioned above.

The FRC Ltd (Fast Road Cars Ltd) website that you've linked to is the company that I've bought most of the Weber tackle for my race car from.

Dave

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2 hours ago, Andy Moltu said:

If you have the standard pump (it is a USA spec car you are converting to triple Webers i presume) it would seem a sound starting point - if when you do a rolling road set up, you find it is running out of fuel at high revs & WOT then might be the time to put an electric pump on.

With may of the electric pumps you may need a regulator - which is what your post was about, however I was going to toss another option into the reconing: could a Stag fuel pump(think the TR8 uses the same) be used? Pump a decent volume at carb pressures and self regulate.

Andy,

No, it's a genuine matching numbers UK TR5 (CP407 L) not a USA spec car so it doesn't have the mechanical fuel pump.

It will go on a rolling road and I want to ensure that it's got sufficient fuel delivery capacity before it goes there. Hence the intention to fit an electric pump and adjustable pressure regulator. I'm not familiar with Stag pumps but know a man who is so will enquire about that. Thanks for the suggestion.

Dave

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