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?
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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.
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.Quote:
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.
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...
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.Quote:
Originally Posted by RedMan16
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.
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.Quote:
Originally Posted by RedMan16
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.
Quote:
Originally Posted by rspears
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 !!!!!!!!!!!!!!!!!:HMMM:
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.Quote:
Originally Posted by glennsexton
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
i plan to go buy the pump, regulator, relay, hoses and all the parts needed for electric pump. im not doing it right this very second im just getting the ideas for what size of pump i need to run it with.
but thanks to all the people who actually helped me out with what to get instead of just talking smack on here. even with all the negative comments im still leaning towards electric so thanks anyways.
I don't think that any comments were NEGATIVE, they were very actual, accurate, replies coming from people with lots of years of experience regarding the issues you asked about---what you do relating to your decision is inrelative to anyone who replied on here as I don't think any of them will PROFIT from your purchases or be a competitor in the other lane at the race track----most of us don't do street racing----------
:D I'd say buy the electric stuff. Then you'll have some real world experience & will be able to make an informed decision the next time you build a street car/truck.
i understand they have experience and know alot about cars. i may not have the same experience as them but i still know my facts. saying what ive heard and know is wrong is just bein a little bit rude and seems like ur trying to act like your smarter than me. just cause im young doesnt mean im stupid with cars.
and i know my choice doesnt matter to them but who cares? this was a simple entry asking what pumps are good not about how it just gives me a "WOW" on the street.
so thanks again everyone
Jesus Christ, "Lighten up francis". Don't take much to get your panties in a bunch does it.
Your first post basicaly stated that you wanted to know what was best for for your STREET application. You were given some very good advise. We on this forum try to help people make the right decisions, not just answer their questions. You dont have to get on a forum just to get a basic question asked. Pick up a book and read it. That is the trouble with you young kids these days, you think that it is your right for us old guys to tell you everything that we know. Not with me, you have to EARN that right in my house.
:eek::eek::eek::eek:
Hey Bug,
Tell us how ya really think !!!!!!
I got yer back on this 1.
First time that puppy overheats in traffic because of the electric fans he just might get the idea that us old farts know what we're talking about.
Like the other millions of cars sold with electric fans from the big 3 & imports.... yeah, they're all broken down on the side of the road overheating! C'mon, get real!
This is a deceased equine, stop beating it!
Ken, I don't think the young man cares about that. This thread is about his acceptance with a peer group. Hundreds of Einsteins answering his questions wouldn't sway him. That's the problem with common sense, it's not all that common.Quote:
Originally Posted by NTFDAY
Yeh and they were all designed that way , his truck wasn't.Quote:
Originally Posted by 34_40
Well, here ya go Red Man!!!! This is more pump then you will ever need, but it comes with a regulator and it's boost referenced should you decide to add a blower or turbo!!!!!!! It will leave room for any engine upgrades you may have planned and if mounted solid will make a terrible racket and overall be very impressive!!!!
MagnaFuel MP-4818 - MagnaFuel QuickStar 275 Fuel System Kits - Overview - SummitRacing.com
THIS seems an appropriate spot to interject a question:
My 73 charger is suffering from heat soak on the carb: the bowls will boil out and flood the engine after it is shut off. Makes it tough to crank unless it first cools off completely.
I noticed the fuel pump gets quite warm, and thought it might be heating the fuel, adding to the problem. I got some insulative tubing to slide over the fuel line, and a Carter electric pump of the same style which has been faithfully fueling my 64 C-10 for about ten years.
BUT, this discussion has me double thinking. Advice?
Phenolic carb spacer and an aluminum heat shield do wonders for a hot carb.. Chargers notoriously suffer from excessive underhood heat....Take a look at the NACA ducts on some of the big block Shelby's, they addressed the problem very well.
First, it's better to start a new thread than to hijack one, but do you have a phenolic or wood insulator block under the carb?Quote:
Originally Posted by firebird77clone
Don't know if I have extra clearance under the hood. I need some play-dough to really be sure.
Notdidnt intend to hijack the thread, thought it might produce some useful information for the young man who started it.
since im a "young kid" i learn by hands on, i tought myself how to build motors and do bodywork. im sorry that i dont have all the money in the world to own everybook i can learn everything from. i dont know all this psi stuff that well so its a simple question to know what kind of psi im looking for. and my truck is mainly street with the occasional strip race. and ya us young kids are so troubled these days. i only built my own truck from the ground up with less than $1000 so i should read a book to learn one simple little fuel pump question huh? let me know how many other 17 year olds you know that built a truck and got 2nd place in a carshow. all i needed to know was what the first guy posted saying 7psi is stock and he thinks the mallory pump is good. i dont need to know that my trucks gonna overheat or use the alternator more. thanks everyone for the concerns but i do know what im doingQuote:
Originally Posted by Bug
Well there youngin, good luck on your project.
7 PSI is too much, you'll need the regulator to cut the pressure back to 4-5 psi as Glenn mentioned. With your engine 110-130 gph is plenty of volume. With the increased volume and pressure with an electric pump you'll also want to use a 1/2" fuel line, available in aluminum also at Sumitt. No reason to have the hi pressure and hi volume if you restrict it through the stock 5/16" fuel line....
No one here is putting you down or saying you don't know what you're doing, just trying to save you a few $$$$$$ from lessons we've all learned along the way......
thats all i needed to know so thank youQuote:
Originally Posted by Dave Severson
is the tank behind the seat in your truck?
Well – this thread has taken some interesting turns – I would again underscore the stock systems are best for cooling and fuel delivery in most vehicles with even serious engine modifications -especially those like your pickup –as GM has really done a great job of engineering. Electric fans can be fine if they are designed as an integral part of the car or if the modifications under the hood preclude the stock equipment due to clearance issues.
As mentioned above, electric fuel pumps can be expensive as they typically require different fuel lines, a regulator, fused circuit, etc. I have most of what Jerry detailed and $500 is real close. I also have an aluminum radiator and a very specialized electric fan setup that is in the $500 range as well. Look at this thread for some additional information on the radiator and electric fans - http://www.clubhotrod.com/shop-talk/...placement.html Bear in mind this is not my daily driver – rather a toy car that provides therapy for my “body-and-soul”.
I know you are young – all of us 60 plus guys were once and speaking for myself, I was pretty cock-sure of my car knowledge. Looking back, I didn’t know that much, but could talk a good line and would never have admitted (at the time) that the dual Holley quads on my ’57 Corvette did not perform as well as the single (stock) AFB! While some of what I’ll share may be real basic, please know that like all the other “old guys” here, I/we have your best interest at heart and would like you consider the hundreds of years of combined experience and hot rod knowledge we bring to the party. Many are long time racers, many have built more engines than we can remember and several of us have had PhDs in pure technical disciplines since before you were born. I commend you on your efforts to date on your truck and would enjoy seeing your handiwork! So please accept the following with the intent in which it is expressed:
Cooling 101 tells us that the cooling systems in most automotive engines have five basic hard parts:
1. Engine block
2. Water pump
3. Radiator
4. fan (including the shroud), and
5. The thermostat.
Water passages inside the engine are usually filled with an ethylene glycol (antifreeze) and water mixture (coolant). These passages (sometimes called water jackets) allow the heat from the block and heads to be transferred to the coolant. The coolant is circulated throughout the engine and the radiator by means of a water pump, which is driven from a belt from the crankshaft pulley. The stock fan clutch assembly mounts on the front of the water pump, and by default is driven by the engine as well. The water pumps only purpose is to move coolant however; it’s a real good place to mount the fan clutch as it’s in the center of the engine bay allowing alignment with radiator in a manner that positions the shroud to most effectively “funnel” air through the radiator and across the engine. Obviously, air flowing past the radiator cools the coolant, and transfers heat away from the engine. The thermostat is used to open or close flow of coolant to the radiator and helps to maintain the engine at a constant temperature. Most SBC run well between 170-190 degreed Fahrenheit. Common misconception number one is that the fan controls the engine temperature – not true, the thermostat controls the temperature. The engineering behind the thermostat is what allows your car to heat up in the winter (stays closed) and run cool in the winter (opens up). Thermostats stuck open or closed can cause engines to run too cool or too hot.
The fan is really important at slow speeds or when idling. As mentioned above, the clutch fan is attached to the water pump shaft and is belt driven from the crankshaft. The fan is not directly attached to the water pump’s shaft; it is actually bolted to a viscous clutch. The clutch then sits between the fan and the shaft. The clutch keeps the fan at a consistent speed when idling, and engages the fan when it is needed. There is an impeller inside the clutch that is connected directly to the input shaft. This impeller is suspended on a bearing allowing the fan and impeller to rotate independently of each other. The housing has a clutch plate mounted opposite of the impeller. The clutch is controlled by a bimetal spring (acts like a thermostat). If the air flowing over the clutch heats up, the thermostat moves the clutch into the impeller and “engages”. The housing is filled with fluid (gear oil). As the clutch moves closer to the impeller, they become coupled by the swirling of this fluid (like a torque converter). The clutch is splined to the housing so the housing rotates and thus the fan (which is bolted to the housing) spins. Conversely, when cool air prevails, the spring relaxes and the clutch disengages. This allows the clutch to slip and the fan “freewheels”. Also at high RPM there is not enough friction to couple the impeller to the clutch so it slips to keep the fan operating at a constant speed and to prevent the fan from taking unnecessary power from the engine. It is important to note is that the fan is only required at idle or when moving slowly when there is not enough airflow through the radiator to provide adequate cooling.
By far, the most common misconception is that the big honking electric fan cools better then the stock metal fan. The fan to cool a 400HP engine is the same size fan as would be used to cool a stock 200HP engine since both engines are producing approximately the same amount of heat during idle and slow speeds. Also mistakenly believed is that an electric fan will cure freeway overheating problems. Remember that the fan is not used at freeway speeds - the natural flow of air through the radiator is more than sufficient (much more than a fan, in fact) to keep the engine at proper temperature. If you’re running hot at freeway speeds, it’s almost always a radiator blockage or coolant flow issue.
Another misconception is “horsepower savings” – they’re just not there. To adequately duplicate the stock mechanical fan, one typically needs a motor that draws between 35 and 50 amps at startup. My fans will blow a 20 amp fuse instantly when they start. When running, my fans draw almost 20 amps. To make this happen, I am converting mechanical energy, to electrical energy, to mechanical again to run the fan. This is very inefficient, much less then just driving the fan directly via the mechanical energy of the rotating shaft.
Also mentioned above - The stock clutch fan can have two failures: the clutch will fail, or the fan will physically break. Electric fan introduces several additional failure points: fuse and fuse holder, all wiring connections (I’d recommend #10 wires), physical failure of the fan, failure of the motor, failure of the thermostat controlling the fan…
So – if you’ve read this far, thank you! Do what you want (we already know you will) but consider and weigh the total cost and risks against a stock setup. You can spend two hundred bucks or a grand – with no noticeable difference in performance. You've done a commendable job on your truck - maybe we can help ya keep a few more of those hard earned dollars (I know they were hard for me when I was 17!! Still are!)
Edelbrock 1721 - Edelbrock Performer RPM Street Fuel Pumps - $95.00
Edelbrock 1721 - Edelbrock Performer RPM Street Fuel Pumps - Overview - SummitRacing.com
A new Flex-a-lite 5555 - Flex-a-lite Fan Clutch -$47.00
Flex-a-lite 5560 - Flex-a-lite Fan Clutches - Overview - SummitRacing.com
A new Flex-a-lite 5718 - Flex-a-lite Standard Rotation Clutch Fan - $41.00
Flex-a-lite 5718 - Flex-a-lite Standard Rotation Clutch Fans - Overview - SummitRacing.com
Regards,
Glenn
so I went and read all your posts----it appears you have a chev 305, ford fe 352 and now a chev 327?????????
my old motor was a 305, i replaced it with a 357. and the ford motor is my one of my friends. and my tank is behind the seatQuote:
Originally Posted by jerry clayton
thank you for all this info here. ive never really considered running a clutch fan because i know of the failure rate which i do not like. im wanting to try electric fans just to see how well they do in my setup. i understand what you mean by it drawing more amperage and if it goes horribly wrong i do plan to stay with mechanical. im wanting to try these new era parts just to see if they perform better or worse.Quote:
Originally Posted by glennsexton
thanks again
Glenn provided you with an excellent and very detailed explanation of both cooling and fuel systems design features. If you read back through all of the posts here without letting your emotions come into play I think you'll see that all of the information was provided with respect, and with an eye on trying to help you get to the right place without throwing your money away. No one here "talks smack" as you put it - probably not capable of keeping up in the "smack" department, and generally don't put up with it anyway. Bottom line, if you choose to stick around you'll find that to a large degree this is a bunch of guys old enough to be your grandpa, and there's a wealth of knowledge that you can pick up for free provided you really want answers and not just instant agreement with your ideas. Like your grandpa or grandma we'll tend to tell you if we believe you're screwing up or headed in the wrong direction, and that's just something that's not going to change. You always make your own choice in the end, right?Quote:
Originally Posted by RedMan16
We really enjoy pictures of projects, and yours sounds like one that has lots going for it. If you decide to hang around with this bunch, maybe you can post up some pictures of your truck, and keep us in the loop as you continue to make changes. Continued good luck on your truck.