Fuel injection and fuel tank connections
Discussion
OK, for those of you who have an EFI system, here is a question...
How did you set up your fuel tank connections? I am thinking of going with two fuel pumps (one for each tank obviously) I will need to add a check valve for each since these EFI Fuel pumps do not come with an integrated check valve (I DON'T THINK)...
Question is, how did you handle/route the overflow (over pumped fuel) into the correct tank? Example: One tank is full, the other is the current tank being pumped from. When the Fuel pump overpumps the fuel will the top crossover handle the increased fuel flow from a EFI pump in the full tank?
Thanks for the help!
Allen
How did you set up your fuel tank connections? I am thinking of going with two fuel pumps (one for each tank obviously) I will need to add a check valve for each since these EFI Fuel pumps do not come with an integrated check valve (I DON'T THINK)...
Question is, how did you handle/route the overflow (over pumped fuel) into the correct tank? Example: One tank is full, the other is the current tank being pumped from. When the Fuel pump overpumps the fuel will the top crossover handle the increased fuel flow from a EFI pump in the full tank?
Thanks for the help!
Allen
I will be running 2 low pressure pumps feeding a surge tank. The surge tank will feed the high pressure pump which feeds the fuel rails. The return from the fuel pressure regulator also feeds the surge tank. The surge tank has 2 overflow lines, one running to each tank. Since the 2 tanks are connected by a cross over tube I really don't care which tank the surge overflow goes to as they should balance out.
I had my fuel tank fitting replaced with -10 an fittings so my cross over tube will be more effective.
If you are running 2 pumps into on line to feed the rails you need to make sure the pumps have check valves in them or install them in the lines.
mark
I had my fuel tank fitting replaced with -10 an fittings so my cross over tube will be more effective.
If you are running 2 pumps into on line to feed the rails you need to make sure the pumps have check valves in them or install them in the lines.
mark
Learned this little lesson from experience. No, the bypassed fuel needs to be routed to the same tank its being pumped from. The crossover connection cannot handle this. Personally, on my EFI, I went with just one fuel pump, linked the tanks together at two of the low mounted AN6 fittings(without the elbows inside the tank), and then returned my fuel into the same tank that it was being pumped from. If you want to run two pumps, then you'll need to find a way to ensure that the returned fuel is going back into the tank from where its being pumped.
Hope this helps.
Cheers!
-Mack
Hope this helps.
Cheers!
-Mack
I've been wondering about this as well. I was aiming at a surge tank on the rear bulkhead with the original carb pumps filling it. I was then going to hunt down a suitable solenoid valve wired to the same circuit as one of the fuel pumps. This would then route the excess fuel back to the correct main tank from the surge tank.
Not found anything suitable yet that is big enough and fuel safe. Hilborn sell a changeover valve that looks nice (read expensive) but it's just a valve and needs an actuator of some sort.
Not found anything suitable yet that is big enough and fuel safe. Hilborn sell a changeover valve that looks nice (read expensive) but it's just a valve and needs an actuator of some sort.
I think he was saying the cross over is connected to the -6 fittings with out the pick up tube.
If I understand what he is saying he pulls from one tank and returns to the same tank. The cross over line in effect feeds the tank that the pump is pulling from with gas from the other tank.
mark
If I understand what he is saying he pulls from one tank and returns to the same tank. The cross over line in effect feeds the tank that the pump is pulling from with gas from the other tank.
mark
Just out of interest, which EFI systems are you using?
Edelbrock proflo? Kinsler? another?
bigmack? you mentioned you've learnt from experience, what happened and have you had any problems with the single connection/pump setup?
Is it possible to have dual tanks and a single fuel filler cap? it seems inconvenient to have to fill both sides especially with the width of the car.
would appreciate any advice.
Edelbrock proflo? Kinsler? another?
bigmack? you mentioned you've learnt from experience, what happened and have you had any problems with the single connection/pump setup?
Is it possible to have dual tanks and a single fuel filler cap? it seems inconvenient to have to fill both sides especially with the width of the car.
would appreciate any advice.
I am going to go with the Edelbrock multiport system (350-3500 SB-Chevy Performer RPM Pro-Flo EFI).
www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1516&prmenbr=361
I had considered the Accel Ramjet system (more expensive) due to tunability, but Edelbrock has since added a PC based software program that allows finer tunability than the softkey pad it provides with the EFI kit. The PC software is about $230 dollars. The soft key pad is fine for quick adjustments due to altitude, etc. but I want to be able to tune it more closely when possible.
There is a thread concerning the single filler and fueling from one side for both tanks.
www.pistonheads.com/gassing/topic.asp?action=bookmark&t=53929&h=0&f=20
Mack, I would assume you valved the return based on which tank is being pulled from. How, and more importantly, what valve are you using?
Thanks for the help guys!
Allen
www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1516&prmenbr=361
I had considered the Accel Ramjet system (more expensive) due to tunability, but Edelbrock has since added a PC based software program that allows finer tunability than the softkey pad it provides with the EFI kit. The PC software is about $230 dollars. The soft key pad is fine for quick adjustments due to altitude, etc. but I want to be able to tune it more closely when possible.
There is a thread concerning the single filler and fueling from one side for both tanks.
www.pistonheads.com/gassing/topic.asp?action=bookmark&t=53929&h=0&f=20
Mack, I would assume you valved the return based on which tank is being pulled from. How, and more importantly, what valve are you using?
Thanks for the help guys!
Allen
I'm running a single Holley 12-920 (225 LPH)inline EFI pump, basically I have a Y off both tanks, through a single filter, feeding the pump. The return goes to the Aeromotive 13109 regulator first, then to a Y back to both tanks. EFI pressure is supposed to be regulated after passing through (or on the way out of) the rail.
11,000 street, miles 2 road course days, 50 drag strip passes, 2 time trials, no problems.
jeff
www.worksstand.com/jeffs.htm
11,000 street, miles 2 road course days, 50 drag strip passes, 2 time trials, no problems.
jeff
www.worksstand.com/jeffs.htm
My GTR has a different engine fitted but this is how I run my system.
Lifter pump in each tank(low pressure) feeding a swirl pot, swirl pot has pressurised feed from lifter pumps so it can sit at any height, the the swirl pot then feeds two high pressure pumps and filters, I have one fuel rail which feeds eight injectors so one pump feeds one end of fuel rail and the other pump feeds the other end, in the centre of the rail is the fuel pressure regulator which returns the fuel back to the swirl pot.Fuel tanks have a 1" bore connecting hose and both tanks are vented on top.
Lifter pump in each tank(low pressure) feeding a swirl pot, swirl pot has pressurised feed from lifter pumps so it can sit at any height, the the swirl pot then feeds two high pressure pumps and filters, I have one fuel rail which feeds eight injectors so one pump feeds one end of fuel rail and the other pump feeds the other end, in the centre of the rail is the fuel pressure regulator which returns the fuel back to the swirl pot.Fuel tanks have a 1" bore connecting hose and both tanks are vented on top.
I had one one of those 3:00 am epiphanies...
I believe that if you used two fuel pressure regulators (one for each pump) then the fuel return from that regulator would go to the appropriate tank. No additional switches or valves required...
Am I missing something? (Seems TOO easy...)
Allen
I believe that if you used two fuel pressure regulators (one for each pump) then the fuel return from that regulator would go to the appropriate tank. No additional switches or valves required...
Am I missing something? (Seems TOO easy...)
Allen
ugh...didn't realize my post would spark such an interest? 
My system is very basic, and a more elaborate plan would be to include an antisurge tank for the track as mentioned. I plan on upgrading it in the near future to include this.
Basically, to answer most everyone's posts, I do not use a valve or check valve with the exception of the vent rollover hoses that have little check valves in them. These are from a sport bike and fit on the Ultima filler necks(which are also from a sport bike). Ultima claim it is a big enough hole for venting each tank, but I'll probably go with something a little bigger in the future having looked at the vent check valves that Fuel Safe and others use.
I linked my two tanks with the lower AN6 fittings that do not have elbows. The elbowed fitting is for your pump. If you have the typical EFI bosche style electric pump (cylinder shaped) I've been told that it should be mounted horizontally on the firewall not vertically. My fuel goes from the left tank to a large sceen filter then to the pump then to a small screen filter and then routes upwards and tees to two fuel rails feeding the injectors and then tees back to the fuel pressure regulator and then dumps into the top fitting on the left tank. If you run it to the other tank(for me the right tank), then it will fill up the right tank with fuel and overflow rather quickly. Mine dumped fuel all into the side pod when I didn't have the rollover check valve fitted. Smelly mess. It was simple, though to just route the last hose to the left tank instead of the right. No biggie really. I have an older Stack dash display, and only use one of my fuel level senders and just multiply by 2 in my head when I look at it. I believe Stack has worked out the bugs now and allows you to use 2 fuel level senders with their dash. Its a decent setup if you don't plan on seeing any hardcore track time with a lot of tight twisties. Otherwise fit a surge tank. Definitely good enough for the road. What's nice about it is that it depletes both tanks together
I like MKoch's approach if going the surge tank route. Use two low pressure pumps (I'd have them hooked up to each tank) and feed this into an antisurge tank and then run your EFI pump from there and dump it back into the surge tank. Kinsler has a really good catalog that shows the correct way to run a surge tank and where the return line should be located. They also sell really good antisurge tanks.
My setup is a Kinsler stack injection with a F.A.S.T EFI with WB02 sensor and is bank-to-bank. I might upgrade later to full sequential, but for me it was more important to spend the money on the WB02 option which is a pretty powerful tuning aid. Fairly simple to tune with a laptop and you can run datalogs of the fuel and spark. My wife helped me with the laptop tuning. She had a blast with it. Good thing she didn't see the speedo though!
Let me know if there's anything else I left off.
Cheers!
-Mack
My system is very basic, and a more elaborate plan would be to include an antisurge tank for the track as mentioned. I plan on upgrading it in the near future to include this.
Basically, to answer most everyone's posts, I do not use a valve or check valve with the exception of the vent rollover hoses that have little check valves in them. These are from a sport bike and fit on the Ultima filler necks(which are also from a sport bike). Ultima claim it is a big enough hole for venting each tank, but I'll probably go with something a little bigger in the future having looked at the vent check valves that Fuel Safe and others use.
I linked my two tanks with the lower AN6 fittings that do not have elbows. The elbowed fitting is for your pump. If you have the typical EFI bosche style electric pump (cylinder shaped) I've been told that it should be mounted horizontally on the firewall not vertically. My fuel goes from the left tank to a large sceen filter then to the pump then to a small screen filter and then routes upwards and tees to two fuel rails feeding the injectors and then tees back to the fuel pressure regulator and then dumps into the top fitting on the left tank. If you run it to the other tank(for me the right tank), then it will fill up the right tank with fuel and overflow rather quickly. Mine dumped fuel all into the side pod when I didn't have the rollover check valve fitted. Smelly mess. It was simple, though to just route the last hose to the left tank instead of the right. No biggie really. I have an older Stack dash display, and only use one of my fuel level senders and just multiply by 2 in my head when I look at it. I believe Stack has worked out the bugs now and allows you to use 2 fuel level senders with their dash. Its a decent setup if you don't plan on seeing any hardcore track time with a lot of tight twisties. Otherwise fit a surge tank. Definitely good enough for the road. What's nice about it is that it depletes both tanks together
I like MKoch's approach if going the surge tank route. Use two low pressure pumps (I'd have them hooked up to each tank) and feed this into an antisurge tank and then run your EFI pump from there and dump it back into the surge tank. Kinsler has a really good catalog that shows the correct way to run a surge tank and where the return line should be located. They also sell really good antisurge tanks.
My setup is a Kinsler stack injection with a F.A.S.T EFI with WB02 sensor and is bank-to-bank. I might upgrade later to full sequential, but for me it was more important to spend the money on the WB02 option which is a pretty powerful tuning aid. Fairly simple to tune with a laptop and you can run datalogs of the fuel and spark. My wife helped me with the laptop tuning. She had a blast with it. Good thing she didn't see the speedo though!
Let me know if there's anything else I left off.
Cheers!
-Mack
I've read this thread with great interest as I plan to go down the fuel injection route myself.
In an effort to understand how this will work and what some of you guys already have I have tried to draw this out :
[pic]http://groups.msn.com/UltimaGTR/shoebox.msnw?action=ShowPhoto&PhotoID=1[pic]
To me this covers the basics but is still not spot on as I would of thought that the surge tank would need a return somewhere as well.
It looks like a nice simple setup and I like the idea of drawing fuel from both tanks at once. I suppose I would just need to flick the fuel gauge over once in a while once the levels get below the tank link to check the levels of each tank.
I could, of course, have completely the wrong end of the stick so please feel free to point me in the right direction if this is all wrong
In an effort to understand how this will work and what some of you guys already have I have tried to draw this out :
[pic]http://groups.msn.com/UltimaGTR/shoebox.msnw?action=ShowPhoto&PhotoID=1[pic]
To me this covers the basics but is still not spot on as I would of thought that the surge tank would need a return somewhere as well.
It looks like a nice simple setup and I like the idea of drawing fuel from both tanks at once. I suppose I would just need to flick the fuel gauge over once in a while once the levels get below the tank link to check the levels of each tank.
I could, of course, have completely the wrong end of the stick so please feel free to point me in the right direction if this is all wrong
454 said:
I've read this thread with great interest as I plan to go down the fuel injection route myself.
In an effort to understand how this will work and what some of you guys already have I have tried to draw this out :
[pic]http://groups.msn.com/UltimaGTR/shoebox.msnw?action=ShowPhoto&PhotoID=1[pic]
To me this covers the basics but is still not spot on as I would of thought that the surge tank would need a return somewhere as well.
It looks like a nice simple setup and I like the idea of drawing fuel from both tanks at once. I suppose I would just need to flick the fuel gauge over once in a while once the levels get below the tank link to check the levels of each tank.
I could, of course, have completely the wrong end of the stick so please feel free to point me in the right direction if this is all wrong
Think it should be low pressure pumps from each tank with non return going into surge.
EFI pump from surge to rail.
Regulator return goes back into surge.
Link tanks top and bottom.
Surge does not require vent.
Steve
this is the diagram I made for myself when I was planning my fuel system
larger image
I though the surge would need an overflow back to the tank. What would happen if the surge tank was completly full? I though the low pressure pump would burn up or that the back up in the return line would raise the fuel pressure.
Canton Racing products made me a custom surge tank if people are looking for them. Ran 125 shipped to my door.
larger image
larger image
Are the factory fuel tanks vented, if so how?
mark
larger image 
I though the surge would need an overflow back to the tank. What would happen if the surge tank was completly full? I though the low pressure pump would burn up or that the back up in the return line would raise the fuel pressure.
Canton Racing products made me a custom surge tank if people are looking for them. Ran 125 shipped to my door.
larger image 
larger image 
Are the factory fuel tanks vented, if so how?
mark
Just a quick follow up. It appears that Kinsler now have their catalog available for download from their website. You may or may not want to purchase anything from them, but I remember that they had some good drawings of fuel surge tanks and plumbing an EFI system. The catalogs are quite massive files though. Just select new products at www.kinsler.com
Cheers!
-Mack
Cheers!
-Mack
mkoch1 said:
.....I though the surge would need an overflow back to the tank. What would happen if the surge tank was completly full? I though the low pressure pump would burn up or that the back up in the return line would raise the fuel pressure.
Are the factory fuel tanks vented, if so how?
mark
Your standard factory pumps will pump until the carb is full. I assume they then stop but have not run mine yet. Anyway it will be normal for the system to arrive at a full condition and deal with it. This will be the same when your surge tank is full.
The tanks have a vent in the side of the filler neck just below the cap. This is piped down to protrude just below the chassis bottom.
Steve
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