Those carbs work fine with the stock mechanical pump so your electric one will work fine. Your rich plugs are not a result of the fuel pump.
looking for advice on which electric fuel pump to get
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Thank you
I really like the cleanliness of this option. Do you have any inclination of the volume and psi of a stand-alone OEM lift pump? Will triples be moving more fuel than 32/36 down drafts? I would think that in theory the answer is no. If they don’t mocr
more fuel and more air, how do they create more
power?
The only carbs I have ever worked on were on lawn mowers.
Primary benefit of the triples is that you have a fuel system for each cylinder.
I thought it was the growl!
Makes sense though. I don’t see a lot of people chiming in to concur with @Mike Goble. Anybody have experience using a lift pump with triples? @Mike Goble - I love all of the ideas that you bring to the table.
I think that a carter will be more reliable, but I can change an intake pump in a snap. Lord knows I burned through enough of them in my VW’s running the tank dry.
I thought it was the growl!
Makes sense though. I don’t see a lot of people chiming in to concur with @Mike Goble. Anybody have experience using a lift pump with triples? @Mike Goble - I love all of the ideas that you bring to the table.
I think that a carter will be more reliable, but I can change an intake pump in a snap. Lord knows I burned through enough of them in my VW’s running the tank dry.
The growl was what originally got me looking at making the change. I love the induction noise. And visually, I think they are a lot more appealing. The performance stuff was what made the change a no brainer.
Not sure why I didn't look further into Mike's suggestion when I did mine; it may have simply not been on my radar screen. I have heard several knowledgeable people recommend it. Obviously, this has the huge advantage of being a BMW-parts based solution. If I were doing this all over again, I probably would look more closely at this.
No matter which solution folks use, I highly recommend buying two pumps and keeping the second in the car as a spare.
To be honest, what Jay Leno calls the "decontentization" of auto parts is another component of my thinking. I don't know if Facets are still made in the USA, but I worry about the ability to source replacement parts for modifications like this. And I think I paid $40 for each of my pumps. So, maybe I could have saved $40, but years from now when my pump goes, I won't be stranded on the side of the road and I won't have to change my setup because the manufacturer is sourcing replacement pumps from China.
Mike Goble
Well-Known Member
I really like the cleanliness of this option. Do you have any inclination of the volume and psi of a stand-alone OEM lift pump? Will triples be moving more fuel than 32/36 down drafts? I would think that in theory the answer is no. If they don’t mocr
more fuel and more air, how do they create more
power?
The only carbs I have ever worked on were on lawn mowers.
I work on carbs all the time - three meals a day....
The lift pump will pump enough to support more power than your n/a engine will make. If it will supply the 280+ HP E28 M5 motors, it will work just fine with three carbs. If I get a chance today I'll time how long it takes to pump a gallon of fuel.
Mike, I like this approach.
Could you be more specific?
Two main parts:
- Sending unit assy metal tank 1612115305
- Suction device with pre-supply pump, 16141179425
Thanks
John,
I didn’t check your part numbers but I used the 318is pump and e28 sending unit. The pump intake needs to be lengthened a bit less than an inch. The bummer is the fuel gauge will read empty when 4-5 gallons remain as it isn’t long enough and there is no other solution.
I didn’t check your part numbers but I used the 318is pump and e28 sending unit. The pump intake needs to be lengthened a bit less than an inch. The bummer is the fuel gauge will read empty when 4-5 gallons remain as it isn’t long enough and there is no other solution.
I sincerely appreciate the feedback in this thread but you are comparing apples and oranges. The e28 M5 has a main pump doing nearly all of the legwork at about 40psi. Most folks with an e28 can at least limp home without a lift pump at all. The pump under the car is the workhorse.
I presume that the comparatively week lift pump by coincidence, has enough flow and a pressure low enough to support the carbs. It is well documented that folks with down drafts are using factory lift pumps, but everyone with triples seems to go with an aftermarket body mounted unit. My preference is to use an in take pump, I just wasn’t sure if it was up to the task with triples. It seems like a non-issue.
Mike Goble
Well-Known Member
Apples and oranges? Injected engines won't run without 40 psi, but we're not talking about fuel injection. We're talking about a carburetor that will perform very well on 2# of pressure. Every drop of fuel that the main pump delivers comes from the lift pump at some head pressure. We tend to think of BMW engineers as competent folks, so I would tend to think that they wouldn't put a lift pump in series with the main pump unless it was capable of delivering the necessary fuel.
I just measured the rate of delivery - 24 gph at the carburetors. If you do the math at a BSFC of 0.5, this pump will support about 280 hp, and you'd have to have a pretty feisty carbureted M30 to make that amount of power. 280 hp will accelerate your BMW to butt-puckering speeds relatively quickly, at which point your foot will reduce the power to some sane amount that your body will accept.
Either you missed my point or I missed yours. Regardless I really appreciate the input. I am asking for a window fan for my living room, and you keep telling me that the warehouse fan is capable of knocking over a grown man.
I am a bit slow on new concepts, but I think that you are saying that the pump certainly deliver enough volume of fuel. Thank you for checking! I don’t know what the PSI recommendations are for something like dual 32/36’s, but we know in tank pumps aren’t overloading down drafts.
You like data. Do you have a good way to test your fuel pressure? I presume that you are equipped, but If you dont have a fuel pressure gauge but are willing to give it a go, I’ll gladly mail you a cheap one. I’ve mailed countless people digital calipers.
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BTW - I will order a fuel pump based on this input. I’m not putzing around with my car anymore. Winter is coming!
Mike Goble
Well-Known Member
Either you missed my point or I missed yours. Regardless I really appreciate the input. I am asking for a window fan for my living room, and you keep telling me that the warehouse fan is capable of knocking over a grown man.
I am a bit slow on new concepts, but I think that you are saying that the pump certainly deliver enough volume of fuel. Thank you for checking! I don’t know what the PSI recommendations are for something like dual 32/36’s, but we know in tank pumps aren’t overloading down drafts.
You like data. Do you have a good way to test your fuel pressure? I presume that you are equipped, but If you dont have a fuel pressure gauge but are willing to give it a go, I’ll gladly mail you a cheap one. I’ve mailed countless people digital calipers.
The dead head pressure is about 2.5-3#. I tested it several years ago when I was looking for an electric pump after I replaced the original B30 motor with the Pierburg pump. The sender from an E28 is about 9" long, which matches up well with the depth of the E3 tank. A little research tonight tells me that the E9 sender is a little longer, about 9.9", so the E28 setup will have about an inch of fuel unavailable if used in an E9.
I also have a pump from a Chevy recommended by Don Lawrence that can be strapped to a stock BMW pump mount.
Thanks Mike!!!
Mike Goble
Well-Known Member
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I've recently jumped down this rabbit hole, albeit on my 2002 (running triple webers on an M20 engine).
Basically the low-pressure in-tank pump was a common practice on early fuel injection cars using a two pump system (low-pressure in tank, high-pressure external). This helps those of us carb guys who want to run just the low-pressure in-tank pump. You may also want to consider running the fun Malpassi/Filter-King Regulator/Filter combo in the engine bay.
The theory (and pumps) are the same, the scaffolding is different (02 vs coupe).
www.bmw2002faq.com
Basically the low-pressure in-tank pump was a common practice on early fuel injection cars using a two pump system (low-pressure in tank, high-pressure external). This helps those of us carb guys who want to run just the low-pressure in-tank pump. You may also want to consider running the fun Malpassi/Filter-King Regulator/Filter combo in the engine bay.
The theory (and pumps) are the same, the scaffolding is different (02 vs coupe).
M20 Triple weber build x2
www.bmw2002faq.com