which electric fuel pump??

[skeepwerkzaz]

I would get the electric kind that bolts to the pad on your motor and runs off of your camshaft. Oh wait I guess that is a mechanical one. But seriously get a good mechanical one, with a bypass-style regulator and never think about it again. Just look around at some seriously big H.P. stuff and notice that the lions share of them all run mechanical. I have a six-diaphragm 130 GPH mechanical that was about $130 new, and can pump WAY more fuel that any other electrical I have run. (holley red, blue, carter, mallory...) Mechanicals have much more power available to run them, and therefore can achieve higher operating psi without suffering flow. (think about the dinky electric motors used to drive a fuel pump!) Most electric flow #'s, (save the $400-500 dollar range) are rated at zero pressure. Add a few lbs. to that and the actual flow drops way below what you think you are getting. Any decent electric should suffice for the N2O, if you are planning on running a separate fuel system, but I would imagine that with a good mechanical, and only a 150 shot, I wouldn't think that would be necessary. Although I have always been intrigued by using something like alcohol as an enrichment fuel
My .02,
Skeep
P.S. "That type of H.P" was being made in the late sixties from the factory. They used 3/8 fuel line, and factory fuel pumps!

[Speedin' Ian]

I was kind of wondering which pumps are the best also. I have a blown 468 runing 11-13lbs of boost with two 850's and I would hate to lean it out. Currently I have a Holley black running to a distribution block which splits it to two regulators. From there I have have four lines, one running to each bowl. I thought this would be more than adequate, but have had people tell me it is not. I just installed a fuel presure guage, the only problem is I could ony install it before the regulators, so it reads the actual pump pressure, which is between 12 and 15lbs. I figured if it dips below 6 or 7 lbs on a pass I'll know that I don't have enough preseure. What do you guys think? Oh yeah the pump is force fed by a t-tank.
Sorry for hi-jacking your thread wet77, but I was wondering about the same thing.

[Rexone]

Mallory or Aeromotive Electrics or the 6 valve mechanicals are all good choices as well as the other one pictured above I'm sure. I'd run any without thinking twice. The Holley is more of a design problem in my mind than a supply one. They don't tolerate any moisture and as soon as any corrosion occurs on the steel vanes they lock up and your volume goes down and also it wipes out the seal and they leak. They're a pain in the ass from that perspective.
But the pump is only a piece of the puzzle. The fuel system must be of adequate design. Good flow, proper regulators, etc , etc. The flow through the blue Holley regulators is pathetic, (look inside one). People get by with them but frankly I don't know why in some applications.
You can get by with a good high flow deadhead regulator (Mallory or Aeromotive) but the preferred method in my mind is a bypass regulator after the carbs and Info and others have promoted here on ***boat. You not only get full fuel volume to the carbs as needed, you get the added cooling effect of returning used fuel back to the tank.
There's lots of threads on ***boat regarding fuel pumps. Do a search and use the resource.

[Bense468]

Mike is right the bypass after the carbs is the way to go. Feed the carbs with what they need/want and bypass the rest. Very nice setup this way, if done right.

[quiet riot]

If you're gonna play "ricky-racer" you are always running good gas, aren't you?
If you use more than 150 hp of the n2o then the increased octane (required for the additional cylinder pressure with lotsa n2o) actually starts being detrimental to performance when not using the n2o. Higher octane gasoline doesn't burn as efficiently/easily as regular gas for lower cylinder pressures (normal compression, low boost, or no extra charge of n2o and gas.) Not to mention that tuning (carb jetting requirements, timing, spark plug heat range) change with different fuels' burining characteristics at the low cylinder pressure. My 10:1 sbf ran 2 mph faster and kept the plugs and exhaust cleaner on the 91 oct pump gas than on 110. I need the 110 oct when running the n2o at 250 hp setting though.
As said earlier, with the small shot of n2o he's planning on using, any decent electric or mechanical pump with enough flow rating at 6psi for the motor and n2o system will work fine. There have been several examples of what people have had good luck with stated above.
A good pump, regulator and return line would be best for keeping steady pressure with the instant bump of the n2o fuel kicking on, that way there isn't the momentary lean out that occurs when the regulator drops and recovers for the fuel of the n2o system. Its not like a carb that has a couple of bowls of gas sitting there ready for full throttle to suck on them and 6psi of pressure to backfill the bowls before they run dry. Its like a fuel injection system that needs the fuel to be pressurized at the point of entry (injector nozzle) all the time to run correctly. Thats why even most of your 4 cyl efi cars have a return line and keep a constant minimum fuel pressure supplied.
If a motor with n2o runs lean enough (say the regulator sticks for a couple of seconds, fuel delivery is blocked, etc) its can burn the best forged pistons in just a couple seconds. This is why I'd recommend the fuel pressure cut-out switch ($25) be wired on the n2o fuel side of any n2o system to shut the n2o off if the fuel isn't there for it to burn with, so it doesn't find another source of burnable material, like the pistons.
boy, I sure ramble a lot sometimes.
jd

[wet77]

I like that idea about the shutoff switch, now I have a daytona eliminator this is going in and it has the tanks on both sides.
Anyone have this setup and have ideas on how the plumbing would look on this
Example: Fuel tanks to a T then to filter then to electric pump.........
Considering the return line I see I have on the opposite end of each tank I have a fitting that looks like it could be opened for a return line attachment, would I have to return fuel to both sides To make them equal in amount of fuel?
Thanks for all the great help