dr_hunt Posted September 22, 2006 Share Posted September 22, 2006 Hey Pop, This is amuZing:) I'm following this thread because I know nothing of fluid dynamics and need help with this too. If this thread stays alive long enough, we'll sort through the answers and have a pretty good idea of what to do in our particular applications. What I need is precise scientific data to support these suggestions. Empirical data is needed too because real-world experiences often differ from mathematical equations and theory. I just need to see the math... HEY DR_HUNT... are you familiar with fluid dynamics??? Well, considering I taught it at New Mexico State University for 3 years while getting my masters, uh, maybe alittle. I'm not sure what science is behind the pump, which is the big equation here. Typically pumps have curves, but what seems to be lacking is a good motor that won't burn up if loaded. That's what I'm seeing. Oversized lines to; 1. keep fuel cool, and 2. Lower the load on the pump, which can be pretty high depending on pump. -10 for me running alky probably isn't big enough, I need to go -12 lines next time around. But when I started all this racing stuff I bought a holley black fuel pump for my 9:1 406 that I converted to alky. What a mistake that was. It would barely feed my "stocker". I went from a 13.30 et down to a 12.58 with the alky changeover on that 9:1 motor, no other changes in the Monte SS. But the point I'm trying to make is that it's the pumps that can't handle the pressure and flow delivery, not the lines. Quote Link to comment Share on other sites More sharing options...
Guest Mike Posted September 22, 2006 Share Posted September 22, 2006 I sense a hint of sarcasm, Doc:mrgreen: Your remarks make perfect sense to me. So fuel pumps have prostates then? Fluid travels through the pump impeded by some unseen thingy. Our only way to address this resistence through the pump's prostate thingy is to install a BIGGER DELIVERY LINE. Man... I wish I could do that!!! What if we install pumps at both ends of the line... one near the carb and one near the tank... one pushing and one pulling? Well, considering I taught it at New Mexico State University for 3 years while getting my masters, uh, maybe alittle. I'm not sure what science is behind the pump, which is the big equation here. Typically pumps have curves, but what seems to be lacking is a good motor that won't burn up if loaded. That's what I'm seeing. Oversized lines to; 1. keep fuel cool, and 2. Lower the load on the pump, which can be pretty high depending on pump. -10 for me running alky probably isn't big enough, I need to go -12 lines next time around. But when I started all this racing stuff I bought a holley black fuel pump for my 9:1 406 that I converted to alky. What a mistake that was. It would barely feed my "stocker". I went from a 13.30 et down to a 12.58 with the alky changeover on that 9:1 motor, no other changes in the Monte SS. But the point I'm trying to make is that it's the pumps that can't handle the pressure and flow delivery, not the lines. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted September 22, 2006 Share Posted September 22, 2006 I sense a hint of sarcasm, Doc:mrgreen: Your remarks make perfect sense to me. So fuel pumps have prostates then? Fluid travels through the pump impeded by some unseen thingy. Our only way to address this resistence through the pump's prostate thingy is to install a BIGGER DELIVERY LINE. Man... I wish I could do that!!! What if we install pumps at both ends of the line... one near the carb and one near the tank... one pushing and one pulling? Electric pumps don't suck very well. FYI the ultimate pump is a belt driven pump, changes flow with engine speed, will support like over 2000HP! Just carry spare belts. Quote Link to comment Share on other sites More sharing options...
Guest Mike Posted September 22, 2006 Share Posted September 22, 2006 Electric pumps don't suck fuel so they suck... Electric pumps don't suck very well. FYI the ultimate pump is a belt driven pump, changes flow with engine speed, will support like over 2000HP! Just carry spare belts. ...but don't these require huge return lines? Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted September 22, 2006 Share Posted September 22, 2006 Yup, bigger is better. Quote Link to comment Share on other sites More sharing options...
Guest Mike Posted September 22, 2006 Share Posted September 22, 2006 Yup, bigger is better. What belt-driven pump do you recommend for a 434 stroker w/ 500HP NA plus 200HP nitrous? Are 1/2 inch feed and 3/8 return lines sufficient for your suggested pump? BTW, this is very cool. I'm about to make another decision!!! Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted September 22, 2006 Share Posted September 22, 2006 What belt-driven pump do you recommend for a 434 stroker w/ 500HP NA plus 200HP nitrous? Are 1/2 inch feed and 3/8 return lines sufficient for your suggested pump? BTW, this is very cool. I'm about to make another decision!!! I have run the aeromotive belt driven pump and the C&S one. Both require -12 lines to the pump and a -10 return, but they flow mondo fuel at any pressure since they are positive disp. pumps driven by the engine, so they don't have hp problems. Quote Link to comment Share on other sites More sharing options...
wheelman Posted September 22, 2006 Share Posted September 22, 2006 One thing I think has been lost in the discussion with Dr_Hunt is that he is running alcohol which requires a much larger volume of fuel than gasoline. So when he says hes running -10 or -12 lines remember it's alcohol and gas won't need lines as large for the same engine. Granted the alcohol engine will be producing more power but will need more fuel to do it. Wheelman Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted September 22, 2006 Share Posted September 22, 2006 One thing I think has been lost in the discussion with Dr_Hunt is that he is running alcohol which requires a much larger volume of fuel than gasoline. So when he says hes running -10 or -12 lines remember it's alcohol and gas won't need lines as large for the same engine. Granted the alcohol engine will be producing more power but will need more fuel to do it. Wheelman Not for belt drive pumps, they will need that size line anyway, they move massive quantities of fuel. Actually I run both, gas and alky. When you design for alky you can switch to gas for the street, which, in my case requires a simple carb change! An interesting note though, CART, F1 and others mandated alcohol fuel over gas because of an explosion and resulting fire that killed several drivers in a race many years back. Not to mention that it makes more power, easier to tune IMO, engine runs cooler, safer for racing IMO, and I'm doing my part to save the world with clean fuel! We had a local racer die this week, Mark Martinez crashed his vette. He hit the wall, popped the windshield out, went over the wall, endoed several times, ripping the carb off the engine, race gas sprayed directly into the cockpit and it caught fire. He was walking around after they put the fire out, took 10 fire bottles, but he had burns over like 85% of his body. Burned the fire suit plum off. Air lifted him to Phoenix, where he died this week of heart failure. Body couldn't take the stress. They couldn't put the fire out, the BG 400 pump just keep feeding the fire until the cell went dry, like 10 gallons! Alcohol is much easier to extinguish, water does the trick in an instant! Edit: My point is that a belt driven pump wouldn't have done that! Quote Link to comment Share on other sites More sharing options...
piston Posted September 22, 2006 Share Posted September 22, 2006 yes, i like the news...i i guess i should throuw in a walbro 255lhp and say its good to go right! the manufacter isa good name, i prety much recommend walbro for most aplications and plus its only 90bucks a pump especially since the 280z is mounted on the outside, an inline is even cheaper. i was going to go the ls1 rought at one point since i found a complete tank with everything still on it and in it for 50 bucks, but i hate doing the cutting and stuff on my spare tire well. walbro for now. Quote Link to comment Share on other sites More sharing options...
Guest Mike Posted September 22, 2006 Share Posted September 22, 2006 I'd opt for alcohol but this is my daily driver. Fuel cost and availability prevent me switching over. Hopefully those obstacles will soon be eliminated. So Aeromotive or C&S with -10 and -12 lines. Okay!! Regarding electric pumps causing fires after accidents... (I'm sure you know this, Doc)... some people use oil pressure safety switches. One could also devise some sort of impact sensor for older cars without such devices and tie that to a cut-off switch. Not for belt drive pumps, they will need that size line anyway, they move massive quantities of fuel. Actually I run both, gas and alky. When you design for alky you can switch to gas for the street, which, in my case requires a simple carb change! An interesting note though, CART, F1 and others mandated alcohol fuel over gas because of an explosion and resulting fire that killed several drivers in a race many years back. Not to mention that it makes more power, easier to tune IMO, engine runs cooler, safer for racing IMO, and I'm doing my part to save the world with clean fuel! We had a local racer die this week, Mark Martinez crashed his vette. He hit the wall, popped the windshield out, went over the wall, endoed several times, ripping the carb off the engine, race gas sprayed directly into the cockpit and it caught fire. He was walking around after they put the fire out, took 10 fire bottles, but he had burns over like 85% of his body. Burned the fire suit plum off. Air lifted him to Phoenix, where he died this week of heart failure. Body couldn't take the stress. They couldn't put the fire out, the BG 400 pump just keep feeding the fire until the cell went dry, like 10 gallons! Alcohol is much easier to extinguish, water does the trick in an instant! Edit: My point is that a belt driven pump wouldn't have done that! Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted September 22, 2006 Share Posted September 22, 2006 Yeah, that is an absolutely fantastic idea that I'm contemplating incorporating into my car now. This is a wakeup call for me! Quote Link to comment Share on other sites More sharing options...
Guest Mike Posted September 22, 2006 Share Posted September 22, 2006 Why not just dump the electric pump and go for a belt drive? Someone very recently suggested this to me:icon44: Yeah, that is an absolutely fantastic idea that I'm contemplating incorporating into my car now. This is a wakeup call for me! Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted September 22, 2006 Share Posted September 22, 2006 Well, there is a tendency to get crap in the belt which screws things up. For a race car probably not a big deal. For anything on the street it isn't a belt you can get anywhere. I'll probably do that for the z, since it's getting a new bigger engine anyway, the pump I have is on a dead head system that I doubt will feed it properly, so might at well take the plunge. Quote Link to comment Share on other sites More sharing options...
Guest Mike Posted September 22, 2006 Share Posted September 22, 2006 So your recommendation is still a belt-drive pump and carry spare belts? Well, there is a tendency to get crap in the belt which screws things up. For a race car probably not a big deal. For anything on the street it isn't a belt you can get anywhere. I'll probably do that for the z, since it's getting a new bigger engine anyway, the pump I have is on a dead head system that I doubt will feed it properly, so might at well take the plunge. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted September 22, 2006 Share Posted September 22, 2006 OK, it is the pump that can't handle the lines and not the other way around. That makes sense to me. So the short story is pick a pump that can handle your target HP and size the lines accordingly. Don't go too big on the pump. BTW, Ford sends a signal from the engine computer to control the pump speed. And instead of a belt driven pump, why not a mechanical? That will also vary with engine speed. JTR makes a BIG deal about hooking the electric pump up to shut off when the engine dies. Makes sense to me. So has anyone ever soldered in a new pick up tube on a stock 240 tank? Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted September 22, 2006 Share Posted September 22, 2006 So your recommendation is still a belt-drive pump and carry spare belts? Not for the street, I'd use electric. I've soldered pickups in tanks, in the factory removable piece, It's a pain, but comes out looking great. FYI, interestingly enought the pump manufacturers will tell you that siphon puts and unwanted strain on the pump. Quote Link to comment Share on other sites More sharing options...
Guest Mike Posted September 23, 2006 Share Posted September 23, 2006 Which electric? Separate pump for nitrous? Regulators? Not for the street, I'd use electric. I've soldered pickups in tanks, in the factory removable piece, It's a pain, but comes out looking great. FYI, interestingly enought the pump manufacturers will tell you that siphon puts and unwanted strain on the pump. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted September 23, 2006 Share Posted September 23, 2006 Which electric? Separate pump for nitrous? Regulators? Check this out. http://www.aeromotiveinc.com/tdetail.php?tip=11 Separate pump depends on HP level your base is at, but I doubt you'll need it. Check with aeromotive, magnaflow, BG, they all make good pumps. Quote Link to comment Share on other sites More sharing options...
Guest Mike Posted September 23, 2006 Share Posted September 23, 2006 An interesting read. Thanks Doc. I'll need to piece together an equation since this is stated textually. I have a pretty good idea of what I need to do... overbuild:) Check this out. http://www.aeromotiveinc.com/tdetail.php?tip=11 Separate pump depends on HP level your base is at, but I doubt you'll need it. Check with aeromotive, magnaflow, BG, they all make good pumps. Quote Link to comment Share on other sites More sharing options...
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