I spent a bunch of time researching this new to me electric fuel pump business. I am replacing the old warped A4 mechanical pump a new Facet from MMI. Thought others might be interested in what I've learned. Don Moyer did a lot of research into these pumps, and most of this is gathered from a search of his notes scattered throughout the forums. If I've got something wrong, then please jump in and provide a correction. I am using the 3 psi pump, not the 4 psi pump model needed in some installations, but most of this applies to both, I imagine.
Note: I am not an expert on this stuff. Reader beware.
I think I have the Facet 477-060E model. From the Facet website, with some modification by me http://facet-purolator.com/index.php...=14&Itemid=36> :
a. 4 - 2.75 max-min psi (nominal "3" psi)
b. 34 gph
c. 1/8-27 INT fitting
d. 24 dry lift inches minimum
e. 74 micron fuel filter built in (replaceable, but not intended for user maintenance, and not intended for primary fuel filtration, hence the recommendation to use a 10 micron fuel/water separation filter upstream of the pump, and a 7 micron filter addon downstream.)
f. No check valve feature (other models do).
g. No positive shut-off feature (otehr models do).
h. About 1.6 amp draw? (that's the average for their whole product line).
i. Self priming and self regulating.
j. The only service normally required is a simple cleaning of the filter and fuel inlet cavity.
---
From the forum archives and other sources:
1. Since the pump pushes not pulls, some wondered if the pump should be placed near the fuel tank, not at the engine. But marine regulations require the pump to be placed within 12 inches of the engine. I suspect this may be in part because the pump pressurizes the line downstream of the pump, increasing the risk of leak and therefore fire (?). In my boat, the tank is above the carburetor and not too far away (6-10 feet seems to be a magic number), so gravity will augment the "suction" created by the pump on the engine pushing fuel into the carb, which is only inches downstream of the pump. It is possible (but expensive and fiddly) to mount a second electric pump at the tank and manually wire it for temporary use, to prime the system by pushing fuel through the lines after maintenance, for example.
2. The pump draws up to 2 amps, hence the 5 amp fuse recommendation.
3. Facet pumps click when running. Fuel flow is regulated internally by a spring-loaded bypass valve, so that the fuel is recirculated internally when the pump's pressure set point is reached. They push not pull (unlike the old mechanical pump?).
4. The A4 carb float valve assembly is designed to regulate fuel flow up to 4 psi, hence use a Facet pump model that produces no more than 4 psi.
5. Universal shipped Atomic 4's from the late 70's with Facet electric pumps. (Ours is a 1974 model engine. We are replacing the presumably original mechanical fuel pump with electrical, since the old pump is now warped.) Facet pumps have a long history in automotive and aircraft applications.
6. The new "E" series Facet pumps are far more reliable than the old models. The new model came out in about 2001 I think, introducing solid state circuitry.
7. This Facet model is designed for continuous duty.
8. Although self-priming, there an be problems if more than 45 degrees off vertical. Mounting off vertical may enhance self-priming, but boats roll.
9. Good mechanical and electric fuel pumps appear to be equally reliable, so other factors enter into deciding which to use.
10. New Facet pumps ship filled with a clear, light oily substance designed to protect the pump's innards during storage and shipping.
11. It is normal for fuel to flow by gravity through both mechanical and electrical fuel pumps. This model does not have the check valve or positive shutoff features of some other Facet pumps. Some suggest adding a second manual shutoff valve at the engine end of the fuel line, just before the fuel pump. This prevents fuel draining through the fuel pump into the carb and therefore bilge if the float valve assembly leaks, even if the primary shutoff valve at the tank is closed. It also facilitates maintenance if the fuel lines at the pump or carb have to be disconnected.
12. Electric fuel pumps are less able than mechanical pumps to deal with slight reductions in fuel line head loss upstream. The result would be fuel starvation issues.
13. 12 volt negative ground is by the pump's metal attachment to the block, so the bracket connections have to be electrically clean.
Photo: my new MMI Facet on-engine pump kit, dry-fitted and awaiting final installation. I'll post a finished picture when I get it done.
Note: I am not an expert on this stuff. Reader beware.
I think I have the Facet 477-060E model. From the Facet website, with some modification by me http://facet-purolator.com/index.php...=14&Itemid=36> :
a. 4 - 2.75 max-min psi (nominal "3" psi)
b. 34 gph
c. 1/8-27 INT fitting
d. 24 dry lift inches minimum
e. 74 micron fuel filter built in (replaceable, but not intended for user maintenance, and not intended for primary fuel filtration, hence the recommendation to use a 10 micron fuel/water separation filter upstream of the pump, and a 7 micron filter addon downstream.)
f. No check valve feature (other models do).
g. No positive shut-off feature (otehr models do).
h. About 1.6 amp draw? (that's the average for their whole product line).
i. Self priming and self regulating.
j. The only service normally required is a simple cleaning of the filter and fuel inlet cavity.
---
From the forum archives and other sources:
1. Since the pump pushes not pulls, some wondered if the pump should be placed near the fuel tank, not at the engine. But marine regulations require the pump to be placed within 12 inches of the engine. I suspect this may be in part because the pump pressurizes the line downstream of the pump, increasing the risk of leak and therefore fire (?). In my boat, the tank is above the carburetor and not too far away (6-10 feet seems to be a magic number), so gravity will augment the "suction" created by the pump on the engine pushing fuel into the carb, which is only inches downstream of the pump. It is possible (but expensive and fiddly) to mount a second electric pump at the tank and manually wire it for temporary use, to prime the system by pushing fuel through the lines after maintenance, for example.
2. The pump draws up to 2 amps, hence the 5 amp fuse recommendation.
3. Facet pumps click when running. Fuel flow is regulated internally by a spring-loaded bypass valve, so that the fuel is recirculated internally when the pump's pressure set point is reached. They push not pull (unlike the old mechanical pump?).
4. The A4 carb float valve assembly is designed to regulate fuel flow up to 4 psi, hence use a Facet pump model that produces no more than 4 psi.
5. Universal shipped Atomic 4's from the late 70's with Facet electric pumps. (Ours is a 1974 model engine. We are replacing the presumably original mechanical fuel pump with electrical, since the old pump is now warped.) Facet pumps have a long history in automotive and aircraft applications.
6. The new "E" series Facet pumps are far more reliable than the old models. The new model came out in about 2001 I think, introducing solid state circuitry.
7. This Facet model is designed for continuous duty.
8. Although self-priming, there an be problems if more than 45 degrees off vertical. Mounting off vertical may enhance self-priming, but boats roll.
9. Good mechanical and electric fuel pumps appear to be equally reliable, so other factors enter into deciding which to use.
10. New Facet pumps ship filled with a clear, light oily substance designed to protect the pump's innards during storage and shipping.
11. It is normal for fuel to flow by gravity through both mechanical and electrical fuel pumps. This model does not have the check valve or positive shutoff features of some other Facet pumps. Some suggest adding a second manual shutoff valve at the engine end of the fuel line, just before the fuel pump. This prevents fuel draining through the fuel pump into the carb and therefore bilge if the float valve assembly leaks, even if the primary shutoff valve at the tank is closed. It also facilitates maintenance if the fuel lines at the pump or carb have to be disconnected.
12. Electric fuel pumps are less able than mechanical pumps to deal with slight reductions in fuel line head loss upstream. The result would be fuel starvation issues.
13. 12 volt negative ground is by the pump's metal attachment to the block, so the bracket connections have to be electrically clean.
Photo: my new MMI Facet on-engine pump kit, dry-fitted and awaiting final installation. I'll post a finished picture when I get it done.
Comment