Fuel Pumps - Electric vs. Mechanical

[patrickt]

Originally Posted by Wbulk

Electric will start that baby right up after setting for a few months...

Wayne, my FE sits untouched from Thanksgiving to Easter, then what I do is crank the engine for about ten seconds with the ignition disabled. That builds up the oil pressure and fills the carb bowls. I then enable the ignition, crank it, and it fires right up. All of this with a mechanical fuel pump. Don't go with an electric just for the "immediate fire up" business -- it's not a big deal.

[Jerry Clayton]

RickL---great post presenting practical view of whys and whynots of both types---and there carb/FI different requirements

Jerry

[Wbulk]

Patrickt,
There is a lot of logic in your argument. I tend to agree.

Wayne

[Rick Parker]

Wayne, my FE sits untouched from Thanksgiving to Easter, then what I do is crank the engine for about ten seconds with the ignition disabled. That builds up the oil pressure and fills the carb bowls. I then enable the ignition, crank it, and it fires right up. All of this with a mechanical fuel pump. Don't go with an electric just for the "immediate fire up" business -- it's not a big deal.

Ditto! me too

[RICK LAKE]

Patrickt and others. You may like or not like my theories about this but here is what I do before each winter. This was before I started using a accusump as a preoiler to my motors.
I run my motor to operating temp and at 180 degrees a defog the motor with marine oil fogger kit and let it stall out.
I remove the valve covers and back off both rocker arm assemblies. There is a down side for me on this, I started with a small hydro lifter camshaft with anti pump up lifters, they don't bleed down no matter how long they sat ( 4 months) The following spring, I reinstall the shafts and the lifters would not bleed down even after running the motor for 20 minutes. The valves stayed partially opened, motor ran like crap. I tryed to back off the adjusters and this smoothed the motor out but was getting valve train noise. My repair for this problem was to remove all the lifters, and clean out the oil in each housing and reinstall in the motor. I didn't have to pull the intake because of the modifications to my single plane manifold. I can slide all 16 out, remove the oil and reinstall in 30 minutes with a piece of wire and magnet. After lifters drained reset the adjusters on the rockers and the motor starts and runs smooth. I now run hydro roller lifters and have not had the same problem.
Once my motor is cool I drain and install new oil and filter, plug the sidepipes, cover the throttle body, and put the car on jack stands, cover and done.
Spring time was reverse remove covers and side pipe plugs, I removed all spark plugs and put rags over the holes and crank the motor until I got good oil pressure. Install new spark plugs, new fuel in the tank, put battery charger on the battery for jump start, turn on the fuel pumps for 15 seconds to clear all the air from my lines, Start the car. It kicks right off and have oil pressure at this time. With FI, the ECU controls the idle on the motor, I don't touch the gas pedal until the ECU brings down my idle to under 900 rpms. At this time my oil pressure is down under 90 psi. I run 15W-40 oil, 1 bottle of Lucas oil suppliment (Quart) and 1 bottle of EOS.
I did this for 6 years with the 452 motor and raced it all the time. It is not street legal, that is not to say that I have not used a dealer plate and driven on the street. After breaking my first rocker shaft at Gateway I installed the 3 quart accusump. This saved my motor from major bottom end damage and kept oil pressure up to 30 psi until the tank emptied and I was back in the pits. I have kept the accusump in the car and use it before starting the new motor, 482 stroker which is using my 452 shelby block. going on 12years of beating and very happy with the way it has lasted. I am looking for another year before going to the new block in the basement with a 498 build and dry sump setup. I could have used the 452 crank and bearings over in another motor, they where fine without any grooves or copper showing on them. This is rods and mains.
I have talked to alot of top people here on the CC forum and FE forum. Everyone has a different way they think is correct to start an engine after a winter in the garage. Some people don't believe in running accusump on there motors, wet or dry sump. I do. I also run very high oil pressure in my motors with tight clearances. Some of this is due to an Aluminum block. I also run Lucas oil which clings to the motor parts, some guys say this is bad for your motor, I have tested this on my own trucks and have found that they startup quiet everytime. There is a down side of this with O2 sensors and hard towing runs. They loose there sharpness and fuel mileage drops a little. I run 100 psi pump and cold have about 130-135 psi in the motor at 1,200 rpm. I let the motor heatup my itself without any throttle touching or RPM change. 3 minutes and I am ready to move the car. I have my pressure at 35-45 psi at idle 800 rpms. Racing 75-80 psi. I am staying with this until a have a failure of either the motor or oiling system. I am not a luck person, so I over engineer anything I can to extend the live of my motor. I also limit the rpms to 6,200 on any motor. IMO this extends the life of the motor about 40% longer than screaming it. It's about matching, motor to rearend ratio and getting the most power to the ground in a certain RPM range. I try to do the most with the least amount of abuse to the motor and car. IMO I don't believe in low oil pressures unless it's strictly a 1/4 mile race car motor.
Bulk As long as you can check the fuel pressure and have 4.5-5.5 psi going into your carb, I see no problem. I have never tryed to run both a electric fuel pump and mechanical together in the same car. I ran one or the other never both. I was afraid of too much fuel pressure for a carb setup or too much pressure build up between the electric and mechanical. Some one else here my be running this way. Not Sure?? Sorry for the long soapbox speech.This is what I do, it works for me. Rick L.

[RICK LAKE]

Patrickt Pat you may be a little over qualified but you should be a Lawyer or Bar Bouncer. You have that SPECIAL Qualitity on busting chops.:LOL : Rick L. Ps get out of the house and go take your better half for a ride, both in and out of the car.

[Tangible Toys]

All the talk of fuel pumps is answered simply, if you have F.I. yes you will need electric, with a carb, mechanical is fine, and the topic of high rpm or H.P.---- those left turn only nascar guys use a mechcanical pump, they buzz at 8000+ rpm through the race, and they have a "little" more then 450 hp. Some times people just like to have "Racing" parts on their street car.

[patrickt]

Originally Posted by Tangible Toys

Some times people just like to have "Racing" parts on their street car.

That's the real truth of the matter. And those same people still play the air guitar to Jimmy Page when nobody's looking.

[jams]

Learn by our mistakes. Only use an electric pump if you have to! Go Mechanical.

Hate the buzz and hum of the electric. Changing to a mechanical was one of my best decisions!

[lnfletcher]

Boy, that's clear as mud!
It's not like us Cobra people to have opinions!

[FUNFER2]

Ricky- quit answering all the questions here, give the rest of us peons a
chance !!!!

Ok, one....... question for you.

With my build of the alum. KC 482 with apx. 600-650 HP.
What are the limits of a mechanical pump ?
What brand is the best and rod ? (damn, went over my ONE question)

[ERA Chas]

From Rick:
"I have never tryed to run both a electric fuel pump and mechanical together in the same car. I ran one or the other never both. I was afraid of too much fuel pressure for a carb setup or too much pressure build up between the electric and mechanical. Some one else here my be running this way. Not Sure??"

That would be me.
When the Sideoiler of about 550HP and quads went in (in '91), it had a mechanical pump only. I installed an Autometer in-car fuel pressure gauge (plumbs antifreeze to gauge, not gas) and had a steady 6-6.5 fuel pressure up to about 5000-5500RPM. From there to 6800, pressure sank to near 4.5 PSI-not what the motor wanted.
I then added a switched Holley Red which is a 7PSI max feeding the Carter. A steady 6.5 to 7PSI under all conditions. Didn't blow the needle valves off, no flooding, no ill affects. No need for regulator or exotic jillion GPM pumps. Much easier hot and cold starting with no wasted cranking. Track MPH improved by 4 or 5. And it's deadheaded-no return plumbing. Admittedly, this is a different engine combination then the OP is using. Only stating what works for me.
I notice many guys wanting Pro Stock fuel systems to feed only 600HP combinations-needless expense and complication. The key is to use just enough 'component' to feed the ideal carb fuel pressure of 6.5 or 7.(aggressive cam / big cubes -smaller engines and lower RPM are fine at 5.5 and Webers only want around 4!) Ride around with a pressure gauge in the cockpit and it will speak volumes.
To answer Wbulk, with the electric switched off, the Carter will pull fuel for only a short time through the Holley. The motor will then stall.
I removed the Holley last year for the first time in 17 for inspection. No debris inside, the gears were in as-new condition. Lightly lubed with assembly lube, safety-wired the base plate and reinstalled. And this is the cheapest electric Holley makes.

[patrickt]

Originally Posted by FUNFER2

With my build of the alum. KC 482 with apx. 600-650 HP.
What are the limits of a mechanical pump ?
What brand is the best and rod ? (damn, went over my ONE question)

If that's 600hp on the dyno with open pipes, then a good old Carter or Edelbrock will do just fine (because you'll be down under 500 hp with everything hooked up). But, if you want some insurance, you can use RobbMc's 550HP Mechanical Pump. http://www.robbmcperformance.com/pro...fordfe550.html BTW, he also makes an 1100HP version of that pump. I don't know anyone that uses it though, only because I don't know anyone with an 1100HP FE.

[Trueoo7]

"If there is one fuel line running from the tank to the fuel pump, your car was setup for a mechanical pump. They are dependable and should last for years. The main thing with these pumps are what the diapham is made of and what fuel will not bother the material. We are getting into more fuels like E85 and this is having issues with some pumps and lines. This is why most auto companies have gone to plastic fuel lines. "

What does this exactly mean? I've been told to stay away from mechanical pumps because the inner diaphram could break or wear out and leak fuel into the oil system and by the time you realize it, its too late.

[Cobra Okie]

WBulk - Keep it simple, especially for a street machine. I have a B & B w/ a mild 302, mechanical pump of course, have over 10K miles in the first year, all in Oklahoma, winter, summer and everything in between, w/ zero problems of any kind. In my opinion, go mechanical, they've proven themselves over the years, especially for low demand engines like ours. Get it on the road and drive the snot out of it!!

[Wbulk]

I agree with keeping it simple. I did go with a mechanical pump.
Thanks.
Wayne

[lnfletcher]

I run a Holley red straight to the carb without return. Mine is mounted below the tank so it has no siphon problems. No problems so far and I know it's working before cranking it and the exhaust drown it out.
http://lnfletcher.homeip.net/66Cobra...files/pump.jpg