Fuel Pumps?

[glenn]

I have couple questions about stock fuel pump:
Does it pump more fuel when engine rev more RPM?
When you spend 10000+USD on the engine, why still use stock fuel pump, any advantage?

Who spends $10,000 on a engine?

Why spend more for a fuel pump than you have to? I'm using the mechanical pump from my old engine. It's doing the job, 6200 miles so far, and cost me $0.

[Rennsurfer]

Why spend more for a fuel pump than you have to? I'm using the mechanical pump from my old engine. It's doing the job, 6200 miles so far, and cost me $0.

Amen to THAT. The older that I get, the more I shy away from aftermarket stuff and lean towards factory components. They last and are engineered much better. Fuel pumps for our engines, for sure, qualify in said theory.

[vwtaiwan]

Hi Glenn. Thank you for your answers and questions. I have a 1966 stock beetle, and lots of millage on it, and I know stock fuel pump work great!
Anyway, still have questions:
Does the stock fuel pump, pump more fuel when you rev up RPM?
What is the fuel flow rate for stock fuel pump?

[glenn]

Does the stock fuel pump, pump more fuel when you rev up RPM?
What is the fuel flow rate for stock fuel pump?

I have no idea.

I have no idea.

I do know unless i'm running it all out for a few minutes it keeps up with the engine. If I were racing it, i guess i'd go electric.

[neil68]

Hi Glenn. Thank you for your answers and questions. I have a 1966 stock beetle, and lots of millage on it, and I know stock fuel pump work great!
Anyway, still have questions:
Does the stock fuel pump, pump more fuel when you rev up RPM?
What is the fuel flow rate for stock fuel pump?

From earlier in this thread:  "One problem with an electric pump is that it has one speed, on or off.  The stock pump is variable.  As the rpms increase, so does the delivery".
 
 
 

[Bruce]

Does it pump more fuel when engine rev more RPM?

Yes, the stock pump is variable flow.  Electric pumps are not.

why still use stock fuel pump, any advantage?

An electric pump is not necessary in all applications.  Some guys like the ease of installation.  No wiring to mess with.

[Bruce]

   PRESSURE IS MEASURED AS RESISTANCE TO THE FLOW!   If you need to ck f/p pressure, then dead-head the the pump, Otherwise ck the flow rate, Gal/Ltrs per min. Under load the floats are down and the needles and seats are open, the pressure should be low. In other words forget PSI and concentrate on flow rates (GPM) when working with a NA carb motor.

With your two carb's inlet valves, they have a fixed orifice when open.  With this fixed orifice, and a pressure reading, you have a measure of flow.  It isn't necessary to go out and find a true flow meter.
Measuring dead-head pressure is worthless.  You need to know the pressure when flowing.

[vwtaiwan]

Does it pump more fuel when engine rev more RPM?

Yes, the stock pump is variable flow.  Electric pumps are not.

why still use stock fuel pump, any advantage?

An electric pump is not necessary in all applications.  Some guys like the ease of installation.  No wiring to mess with.

Thank you Bruce.
Does the fuel pump spring float like valve spring when you rev the engine RPM too high? Will it cause carburator ran out of fuel  when people drive really hard.

[Rasser]

Electric pumps noisy?  nooooooo   
<a href="http://www.youtube.com/v/KfO_BEsGONM" target="_blank">http://www.youtube.com/v/KfO_BEsGONM</a>

[glenn]

That will get old real fast.. maybe 2-3 laps.

[peach_]

That will get old real fast.. maybe 2-3 laps.

Are you mad? Its a Race Car! our race cars run two pumps low and high Pressure pumps, Who gives a Shit how loud the Fuel Pump is when you've got a Straight cut dog box, diff wine, Induction and no sound deadening, plus your wearing ear plugs???

That video has nothing to do with the question i asked about fuel pumps and is totally off topic!

Thanks to Everyone else for there great replies, was really interesting to see other ppls thoughts, but im going to borrow a CB fuel pump from a mate for peace of mind, Slight over kill but Id kick myself if i went with the stocker and it leaned out on a long run.

cheers

[Jason Foster]

[Rasser]

That will get old real fast.. maybe 2-3 laps.

Are you mad? Its a Race Car! our race cars run two pumps low and high Pressure pumps, Who gives a Shit how loud the Fuel Pump is when you've got a Straight cut dog box, diff wine, Induction and no sound deadening, plus your wearing ear plugs???

That video has nothing to do with the question i asked about fuel pumps and is totally off topic!

Thanks to Everyone else for there great replies, was really interesting to see other ppls thoughts, but im going to borrow a CB fuel pump from a mate for peace of mind, Slight over kill but Id kick myself if i went with the stocker and it leaned out on a long run.

cheers

I actually run a rotary electric fuel pump from CB. It´s quite if you make sure to rubber mount it. You can just barely hear it with engine shut off and pump running.
I have only once experienced that the pump could not deliver (I run 8mm/AN6 from fueltank to carbs), this was when i was out testing how fast the car would go. After a looong high speed run on the highway (no crosswinds and empty late night highway) I noticed it ran leaner and leaner when getting closer to 120-130mph (I use an AFR gauge). This was without doubt caused by the fuelpump! But this is extreme conditions and I still run the same pump because that high speeds is only tried/tested ONCE. It´s not a problem on the 1/4 mile, and not a problem in normal driving conditions (I never drive at sustained speeds above 100mph).

If you wan´t to make sure you don´t lean out, then the only way is using an AFR gauge, which I also mentioned in a previous post in this thread.
When you can hear/feel your car misfires due to a leanout caused by the fuel pump not beeing efficient enough, then you have been running lean for some time before that happened! it´s too late then!!!

Yes the video was a bit off topic, but thought it would make someone smile, and not the opposite    sorry bout that.

[glenn]

Yes the video was a bit off topic, but thought it would make someone smile, and not the opposite    sorry bout that.

Made me smile.

[Stephan S]

I lost the bolts for my pump.   

Same here
 

I lost another Holley #12-801 fuel pump (same style as the old "red") last weekend, coming back from Orange County! Let's just say it was pretty interesting, when it happened on the freeway and I was in the third lane...

I'm done with these Holley pumps. I had this one installed just before the '08 Classic Week, after another fairly new Holley I had gave up. I guess I should have learned my lesson.

A CB Performance rotary pump is on its way. They have 2 models: 5.5lbs and, if you have a regulator (my case), 3.5lbs. I'm following Pat Down's advice and use the latter. It is also said to be MUCH quieter than the Holley pump.

Car should be running again this week. Thankfully, the fuel tank is not too full, which should make the conversion easier!

[Rasser]

I lost the bolts for my pump.   

Same here
 

I lost another Holley #12-801 fuel pump (same style as the old "red") last weekend, coming back from Orange County! Let's just say it was pretty interesting, when it happened on the freeway and I was in the third lane...

I'm done with these Holley pumps. I had this one installed just before the '08 Classic Week, after another fairly new Holley I had gave up. I guess I should have learned my lesson.

A CB Performance rotary pump is on its way. They have 2 models: 5.5lbs and, if you have a regulator (my case), 3.5lbs. I'm following Pat Down's advice and use the latter. It is also said to be MUCH quieter than the Holley pump.

Car should be running again this week. Thankfully, the fuel tank is not too full, which should make the conversion easier!

That´s the type I´m running.  VERY quiet, and it has lasted 20-25000km (4 years) so far. I bought the 3.5lbs version, but now car and engine is uprated and I have regulator installed - maybe I should step up to the 5.5lbs (and then just carry the 3.5lbs in the car, just in case of pumpfailure ;-) )
What really makes a difference in how much noise it makes, is whether or not it is rubber mounted - huge difference! 
Don´t use the bracket that comes with the pump, make one yourself and rubbermount it somehow.

Good luck with your new pump.

[low oval]

I just installed the 3.5 cb perf. fuel pump today. can't even hear the pump when the engine is running, and barely can hear it inside the car with out it running.  I used the bracket that came with the pump however.  I went to this after going through 3 manual fuel pumps in the last couple of years. 

[67worshipper]

im running a 3.5psi cb pump after the holley drove me insane.when running the holley i took the car for an mot test and the tester thought we were under attack after i switched the ignition on as the rest have said its more than enough pressure for day to day and really quiet if youve run a holley.

[Rasser]

Just thought of one thing that i really don´t like about the mechanical vw pumps - The pipes in the pump, that you connect the hoses to, can all to easily get loose. I experienced this once - a friend noticed that fuel was coming out at the pump, luckily nothing happened. I then had the exact same thing happen again later with a new (old) pump. If I were to ever use a stock pump again, then I would make sure to have the pipes soldered to the pump (sorry don´t know the correct term in english, but hope you understand me).

Has anyone else experienced that the pipes get loose at the pump, and this resulting in fuel all over the engine compartment?

Rasmus

[Diederick/DVK]

i rubber mounted my holley pump using the mercedes mounts and i guess it's not us that's under attack but my neighbours so it does dampen the sound. problem is that the mercedes mountes are about 12mm thick rubber so i'm afraid it does whobble about.

another question that came to my mind is, assuming that most people here with big engines use -6 AN fittings for the fuel system, how do you connect the CB pump which has barb fittings? if i wanted to swap the holley for the rotary pump the fittings are just too small.

[Neil Davies]

Just thought of one thing that i really don´t like about the mechanical vw pumps - The pipes in the pump, that you connect the hoses to, can all to easily get loose. I experienced this once - a friend noticed that fuel was coming out at the pump, luckily nothing happened. I then had the exact same thing happen again later with a new (old) pump. If I were to ever use a stock pump again, then I would make sure to have the pipes soldered to the pump (sorry don´t know the correct term in english, but hope you understand me).

Has anyone else experienced that the pipes get loose at the pump, and this resulting in fuel all over the engine compartment?

Rasmus

I've had that happen, and ruin an otherwise perfect pump! Pulled the rubber pipe off and the metal tube came straight out...

[Jim Ratto]

Just thought of one thing that i really don´t like about the mechanical vw pumps - The pipes in the pump, that you connect the hoses to, can all to easily get loose. I experienced this once - a friend noticed that fuel was coming out at the pump, luckily nothing happened. I then had the exact same thing happen again later with a new (old) pump. If I were to ever use a stock pump again, then I would make sure to have the pipes soldered to the pump (sorry don´t know the correct term in english, but hope you understand me).

Has anyone else experienced that the pipes get loose at the pump, and this resulting in fuel all over the engine compartment?

Rasmus

we used to get a lot of cars with black decklids on the tow hook because of this. Either that or the fuel pipe going into stock carburetor would make a run for it and you'd have Dante's inferno in no time.
My car, with Super Flow 2276 engine, 48IDAs, mag, would not run on stock fuel pipe in pan, even with Holley Pump and bigger hose on the suction side (tank to pump). On a long grade, on the freeway, it would dry float bowls if I really gave the car the full beans. I went to AN-6 line with that motor, drilled fuel inlets into carbs (where banjo bolt threads in), after trying 2.50 needles. Finally it would hold its own up the grade.
 BTW I had more than $10,000 (1991-92 dollars) in this motor. Not that I was smart.... 
My 2165 now runs fine on 8mm line from pressure side of pump to carbs. No more Holley regulator for me either.... I ran out of swear words for it. Went with Malpassi Filter King.

[67worshipper]

Electric pumps noisy?  nooooooo   
<a href="http://www.youtube.com/v/KfO_BEsGONM" target="_blank">http://www.youtube.com/v/KfO_BEsGONM</a>

bloody hell i thought my car was loud.at least you have an excuse for not talkin to your passengers

[Jon]

I wish regulators was sold with instructions.

[fredy66]

sorry i now this is a old topic but i was readind and the i have a quesion.
Way not have a Weber pump on Weber carbs  ??


http://www.dellorto.co.uk/editor/uploads/images/WFP502.PDF

[Kaferdog]

another question that came to my mind is, assuming that most people here with big engines use -6 AN fittings for the fuel system, how do you connect the CB pump which has barb fittings? if i wanted to swap the holley for the rotary pump the fittings are just too small.

  I would like to know the answer to this also...!

[Kaferdog]

Ha...... .....I answered my own question...!!!!...

http://www.jegs.com/i/JEGS-Performance-Products/555/100581/10002/-1?parentProductId=1167165

[Fiatdude]

I have couple questions about stock fuel pump:
Does it pump more fuel when engine rev more RPM?
When you spend 10000+USD on the engine, why still use stock fuel pump, any advantage?

Who spends $10,000 on a engine?

Why spend more for a fuel pump than you have to? I'm using the mechanical pump from my old engine. It's doing the job, 6200 miles so far, and cost me $0.

Who spends over $10K on a engine??? I do -- almost eveytime I build an engine -- unless it is a bone stocker -- And the quickest way to lose an engine -- to lean the bitch out and melt some pistons or heads -- I'm sorry if I want to spend a little extra to have what I think is something a little better.

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I would like to add one thing -- the reason why there is such a high failure rate for the holly pumps is that they are very over rated for our "little" engines -- they build up heat because no fuel is going through them to keep them cool. If you want one to live you should put a by-pass regulator and return line in your system so that fuel is constantly cycling/flowing through the pump.

.