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Michael Oritt
03-16-2008, 07:04 PM
I've been using FACET pumps in the Elva and have been let down by them once too often. I've used both the older "cube" pumps and the newer supposedly improved configuration with the rounded top in the black plastic case(shaped kind of like a mantle clock) in 2-4 psi and at least three of them have failed--never totally but just enough to cause fuel starvation at high speeds.

What is the collective wisdom and recommendations on fuel pumps for SU's? I have twin HS6's on an MGA engine with negative ground setup in the car.

ChrisS
03-16-2008, 07:38 PM
I use a Holley 12-801 vane pump with a Mallory 3 port regulator. I used the 2 port Holley 12-804 regulator but had over pressure problems. Others have had good luck with the 2 port regulator though. This is for twin HS-2's.

DrEntropy
03-17-2008, 08:07 AM
Not sure if the volume requirement of the HS6's on the engine you're using are similar (tho I suspect so) but I recently replaced a Facet with a Carter in-line low pressure one, #P-60504 on the Alfa with no need for a regulator. It's a 1750cc (9:1 comp, 11mm lift cams) using twin 40mm DCOE's as aspiration. Haven't had any fuel starvation issues and I rev the poor thing mercilessly.

Just a thought.

racingenglishcars
03-17-2008, 10:09 AM
It's not so much the volume requirement of the carbs, but of the engine. That is directly determined by the HP output and the thermal efficiency. The fuel contains about 42700 [kJ/kg]

aeronca65t
03-17-2008, 11:06 AM
I installed a low-pressure Facet "cube" pump (with pressure regulator) around '96.

It's been solidly reliable since then. I *hate* the sound of the thing, but never had any reliablity problems. They are a very simple design with few moving parts....not a lot to go wrong.

For a street car, I think I'd prefer a quieter, vane type pump that others have mentioned...something like ~This Carter Pump~ (https://store.summitracing.com/partdetail.asp?autofilter=1&part=CRT%2DP4070&N=700 +400415+307759+115&autoview=sku)

Biff
03-17-2008, 01:42 PM
Michael,

I've been running one of Advance Auto's Master Universal Fuel Pump, part# E8012S for the last 4 years. You will need a fuel pressure regulator as this pump puts out in the 5 - 9 psi range but pumps up to 30gph. Here is a link https://tinyurl.com/yo4xg2

DrEntropy
03-17-2008, 03:34 PM
It's not so much the volume requirement of the carbs, but of the engine. That is directly determined by the HP output and the thermal efficiency. The fuel contains about 42700 [kJ/kg]

umm....


Not sure if the volume requirement <span style="font-style: italic"><span style="font-weight: bold">of the HS6's on the engine you're using</span></span>

Thought that was what I said. But without the involvement of all them Joules, Donn. :smirk:

Dave Russell
03-17-2008, 04:46 PM
To add to the confusion,

The brake Specific fuel consumption of an engine ranges from 0.35 to 0.6 lb/hr/hp. Average is about 0.5 lb/hr/hp.

This translates to:
The average engine, when putting out 100 hp, will require about 8 gallons of gasoline per hour.
D

Michael Oritt
03-17-2008, 05:36 PM
The Facets--when they worked--worked fine but have simply proven unreliable so I am looking for a relatively bulletproof pump/regulator set up. BTW depending on the track the Elva burns one gallon every 10-12 minutes.

Dave Russell
03-17-2008, 06:42 PM
What pump do you presently have on your BN1? Is it reliable?
D

Michael Oritt
03-17-2008, 07:39 PM
Dave--

As you probably remember from the several times that this subject has come up on the Healey forum I have an SU solid state as the "primary" with a FACET cube as a back-up mounted between the SU and the tank, the pumps plumbed in series with an "on-off-on" selector switch. The SU pulls nicely through the FACET and the FACET pushes through the SU, etc.

Because the SU is quieter I seldom run the FACET except to make sure that it works. If the definition of reliable is that it has never let me down then the SU is reliable (probably only because there is a back-up installed) and the FACET is essentially untested.

On the Elva I have two FACETS plumbed in a similar manner but on separate SPST switches. For whatever reason my experience with them is that they are NOT reliable and since they are essentially each primary I would simply like a more bullet-proof setup.

BTW I posted the same question over on the Vintage Race and VRG newsgroups and have gotten numerous recommendations--almost all different--ranging from Mallory, Bendix, Holley, etc. etc. Perhaps reliability is, in the end, merely an evaluation based solely on empiric observation.

Dave Russell
03-17-2008, 09:18 PM
Quote:

"If the definition of reliable is that it has never let me down then the SU is reliable"

So why not put an SU pump on the Elva? Just an empirical observation.
D

aeronca65t
03-18-2008, 05:10 AM
If it were me and I was going to run a second fuel pump (which I'm not), I'd run the pumps <span style="font-style: italic">in parallel</span>.
With separate "#1" and "#2" switches.
And I'd run "#1" at a session and then "#2" at the next session...back and forth to make sure they were both in use on a regular basis.

Maybe I'm off-base here, but it seems that if one got clogged or somehow internally failed (in a series setup) you'd be dead in the water.

By the way, I just noticed that you can buy an ~Empi Electric Fuel Pump~ (https://www.jcwhitney.com/autoparts/Product/tf-Browse/s-10101/Pr-p_Product.CATENTRY_ID:2011022/p-2011022/N-111+10201+600002064/c-10101) that's similar to the Facet but is intended for old VWs. Since it's listed as having a 1.5 to 4 lb pressure range, it might work in Brit-cars without a pressure regulator.

Michael Oritt
03-18-2008, 07:19 AM
Dave--

Even though something may be highly reliable, it and parts for it must also be easily replaceable (findable). You can find Carters, Holleys and yes FACETS at most Auto Zones, etc. but you won't find SU's.

Nial--

When I first installed a spare pump on my Healey I assumed that mounting them in parallel would be the best way to go. However I found that if there is any leakage whatsoever through the built-in check valves in either pump then a large part of the fuel supplied by the other will take the path of least resistance and recirculate back through the leaky valve and so around in circles and starve the engine. Also, a parallel installation requires a larger number of fittings=potential leaks and is rather bulky.

If this and other failure scenarios seem unlikely I agree--but I have encourntered it and so try to avoid it.

Does anyone have thoughts on a Blue Holley #12-80201 with a pressure regulator? It--and the Carter Universal Marine rotary pump w/a similar regulator--seem to have many advocates in MG racing circles.

JerryB
03-18-2008, 02:06 PM
First thing is to check the fuel cell for degrading foam.

Cut open the filter before the pump and examine it for tiny pieces of foam or cell trash. This will kill a pump quickly.

Any of the TI Pierberg rotary type pumps work well. They are sold under a variety of aftermarket names. 6 GPH is doable easily.

Using pumps in parallel means check valves which arent cheap. (the good ones at least).

03-19-2008, 07:58 PM
My 2c (which with the exchange rate as is is worthless).

While I ran triples, I tried to power them with a Carter low pressure pump. I checked the model both on the box and the pump and it was right.

It was supposed to not exceed 3psi. It was well over 15 when the gauge pegged. My carbs didn't like that at all.

What a mess...

They may be good pumps, but imo the QC isn't. ymmv of course.

Michael Oritt
03-20-2008, 05:03 PM
Looks like this string has...run out of gas.

As always I appreciate the various opinions and recommendations. I'm going with the Blue Holley.

WhatsThatNoise
03-21-2008, 05:59 AM
Quote:
So why not put an SU pump on the Elva?

Actually...That's what I'm running with my H6 carbs....
No problems....Yet
And the Elva has the fuel pump under the scuttle on the passenger's side....(Very easy to get to)

BTW....What are you doing running 1 3/4" carbs in VSCCA? :cooler: Mr. Nobodies-Looking :smile:

Michael Oritt
03-21-2008, 07:06 AM
1 3/4" carbs in VSCCA?
------------------------------
Dear Mr. Nosy-Body:

1-3/4" carbs were a legal modification back "in the day". BTW I run VSCCA-legal (drum brakes all around, Riley rear axle and narrow Dunlop L's) in other groups (SVRA, etc) as well.

Now tell me about your Hoosiers?

DrEntropy
03-21-2008, 07:40 AM
:lol:

Those pix of THREE of those things side-by-each is charming, BTW.

Nostalgic.

:thumbsup:

WhatsThatNoise
03-21-2008, 05:14 PM
If yer gonna run 1 3/4's....
Ya have to be sneakier than that :yesnod:

Racing has elevated cheating to an art form.
Time to step up :hammer:

You almost need a caliper to distinguish the difference between a H6 &amp; a H4.

The HS6 is shorter and has that hose on the bottom.
Dead giveaway.

NOTE: BOTH require that you cut off the 4 stud holes and tig 2 of them back on (top &amp; bottom)
So they fit the original MGA intake.

This is where the art come in....You have to be a sculptor who works in aluminum to make it look perfect.

HS6 is a "MGB carb"....WAY after Dec 1959