Thread: fuel pump selection

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im running a 450 hp 357 small block chevy and i want to switch to an electric fuel pump. im looking in summit cateloges and i dont know what size to pick. what psi and gph should i be running to give me the best performance for street driving?

Everyone here will have a different opinion on what electric pumps are "the best". I've had good luck with Mallory units - 110 Series Electric Fuel Pump is a high volume fuel pump for under $200. The operating fuel pressure is factory set at 7 PSI so you'll want to run a fuel regulator to keep your pressure at 5psi at the carburetor inlet.

Can I ask what's the reason you're going away from the stock mechanical unit? Chevy SB mechanical units are known for dependability and they don't require a regulator. They'll definitely keep up with 400 horsepower.

alright thanks.
and im going with electric fans and fuel pump just to get back the little bit of horsepower they take away.

Originally Posted by RedMan16

alright thanks.
and im going with electric fans and fuel pump just to get back the little bit of horsepower they take away.

I'd say you need to refine your calculations and consider all the variables. It really does not matter how the work is done, the energy to do the work is still expended. With electric fans you have increased load on the alternator, plus the questionable performance of the electric fans compared to mechanical. Unless you're dealing with a space problem you're going to be miles ahead sticking with the mechanical fan and factory type shroud. Same with your fuel pump - you're adding complexity by switching to electric (regulator, etc) and the power to drive the motor is still coming from your engine. Someone's sold you some bad information if you believe you're making power by switching to electrics. There's no free energy, period.

thats true to what you are saying but having a 6 blade fan does have wind resitance which makes it harder for the motor to spin it. even a clutch fan gives more power back. im not saying its a whole lot but since the alternator is always there it will just be charging more often and that still isnt as much power loss as the fan and pump put on it.

Ouch - nothing cools like the fan that came with your truck. Stay with the factory fan and shroud. The GM fans actually disengage at speed and take very little away from the mix. As mentioned above, electric fans are okay if you have a clearance problem. Same with fuel pump..

Just sayin...

Originally Posted by RedMan16

thats true to what you are saying but having a 6 blade fan does have wind resitance which makes it harder for the motor to spin it. even a clutch fan gives more power back. im not saying its a whole lot but since the alternator is always there it will just be charging more often and that still isnt as much power loss as the fan and pump put on it.

The alternator is "always there", but if it is not loaded it free wheels. If it's driving your fan & pump, it requires work, which equates to fuel, which balances with the mechanical units. There's no free lunch, regardless. Do yourself a favor and leave the mechanical parts in place.

getting rid of 2 mechanical parts putting a little more amperage on 1 doesnt equal the same amount of power. yes it does take power to turn it but not as much as both mechanical parts. your the only person ive ever heard say its the same. all the forums and magazines i have read say going electric gives you back horsepower and mpg. and all my friends who went electric notice small power differences also.

No disrespect meant, by all means, but, in my opinion, if your friends are saying that they notice a power difference (as in HP) in a street car, they are probably imagining it. They think that it is so they feel that it is.

That being said, if you plan on racing quite a bit, I would go with the electric fan and fuel pump. The fan because of high RPM's (have you ever had a clutch fan sieze up. Not pretty) and the fuel pump for continuous fuel flow. I do know of one person that used to run a mechanical fuel pump and his car would starve of fuel at WOT and around 1000 ft. But that was with a lot more than 450 HP.

You will never notice the difference in power seat of the pants---and even on a dyno the horsepower savings are negligible and mostly in the upper RPM ranges where you don't run on the street anyway. Another thing I always take into consideration, I can go into most any parts store and pick up a mechanical fuel pump or clutch for the fan when I'm out on a road trip somewhere. The same can't be said for electric pumps and fans. The people who sell the electric pumps and fans and other race parts will make a lot of unsubstantiated claims concerning performance improvements when using their products but the real world gains are more then offset by the added expense and inconvenience of loading up an electrical system with unnecessary electrical components. When running a lot of the extra electrical components you will also need a higher output alternator, which is more expense.....

thats pretty much what i use it for is racing. it is my daily driver but i do cruise on weekends and street race. also go to the drag strip every friday night. i wouldnt normaly switch over but i do need a new fuel pump so i might as well go with electric and for the fans are good in stop and go traffic which i drive through everyday.

Originally Posted by RedMan16

thats pretty much what i use it for is racing. it is my daily driver but i do cruise on weekends and street race. also go to the drag strip every friday night. i wouldnt normaly switch over but i do need a new fuel pump so i might as well go with electric and for the fans are good in stop and go traffic which i drive through everyday.

With all due respect, it sounds more like this is your only transportation, and you like to play around doing stoplight sprints and running at grudge night drags, but you still have to drive it home, and you want it to start and run Monday morning to go to work. The magazines, internet forums you're surfing, and advertising hype you're falling for are leading you astray. Go to your high school physics teacher, pose the question to him/her, and believe the calculations they do to show you that work is work, and regardless of the energy source (direct crank HP or crank HP making electricity driving a motor to do equal work) the resulting power to the wheels is very, very nearly the same. Dave (years of very real race experience) spelled out the reliability and replacement side very well; Bug pointed out that if it's a high rpm, race only application then electric might make sense; and Glenn explained the OEM system well.

Once again, do yourself a favor and replace your mechanical fuel pump, and leave your fan alone. The only thing you're going to gain is some "WOW" factor from your cruising buddies, and make your truck less reliable.

Originally Posted by rspears

With all due respect, it sounds more like this is your only transportation, and you like to play around doing stoplight sprints and running at grudge night drags, but you still have to drive it home, and you want it to start and run Monday morning to go to work. The magazines, internet forums you're surfing, and advertising hype you're falling for are leading you astray. Go to your high school physics teacher, pose the question to him/her, and believe the calculations they do to show you that work is work, and regardless of the energy source (direct crank HP or crank HP making electricity driving a motor to do equal work) the resulting power to the wheels is very, very nearly the same. Dave (years of very real race experience) spelled out the reliability and replacement side very well; Bug pointed out that if it's a high rpm, race only application then electric might make sense; and Glenn explained the OEM system well.

Once again, do yourself a favor and replace your mechanical fuel pump, and leave your fan alone. The only thing you're going to gain is some "WOW" factor from your cruising buddies, and make your truck less reliable.

Yaeh, and he can tell his buddy's he's got MAYBE 1 -2 more HP @ the flywheel
3/4 or so to the ground !!!!!!!!!!!
I don't believe sum people !!!!!!!!!!!!!!!!!

Originally Posted by glennsexton

Everyone here will have a different opinion on what electric pumps are "the best". I've had good luck with Mallory units - 110 Series Electric Fuel Pump is a high volume fuel pump for under $200. The operating fuel pressure is factory set at 7 PSI so you'll want to run a fuel regulator to keep your pressure at 5psi at the carburetor inlet.

Can I ask what's the reason you're going away from the stock mechanical unit? Chevy SB mechanical units are known for dependability and they don't require a regulator. They'll definitely keep up with 400 horsepower.

What Glenn said. Mallory pumps are very reliable, don't make a lot of noise, and you don't necessarily have to run a return line to the tank. I run one on my '32 and have had good luck with it. The Holley I had originally puked out after 3000 miles.

With a nice size electric pump----expect to spend more in plumbing parts/hoses, etc than the cost of the pump
and an regulator that works will cost almost as much as the pump---you can expect to spend probably $500 by the time you are done with the plumbing and wiring, relays, dead man switches ( crash/rollover, oilpressure,etc)

On the electric fans---if you expec to cool a high performance engine you will end up with a fan system that pulls aprox 40 amps and you will need to upgrage your alternator/wiring,relays, temp sensors-----and be careful working on the engine cause the fans will probably come on unexpectedly-------blood is hard to clean up after its dried and it will be dried before they get done stiching up your fingers