Zoldman Posted September 7, 2004 Share Posted September 7, 2004 After doing all the searches I can think of, I think I like the fuel sump solution to cornering starvation better than any other method, except for one nagging issue. What kind of ground clearance do you need to be real safe with a sump hanging down? The two sumps I found at Jegs and Summit are about 3 inches deep. The bottom of my tank is about 8-9 inches off the ground now, which will leave me with 5-6 inches (figured that out all by myself). What would a safe minimum be? I've got good stiff Arizona Z springs and Illuminas, so rear squat is not excessive. My car is an early 260. The engine is a '95 LT1 being massaged to make 425 at the flywheel, which means I will need a 3/8" fuel supply, by my math. Also, has anyone had long term experience with using the drain plug fitting in the bottom of the tank? My searches turned up some discussion of doing this, but no difinitive answer as to whether it solves the cornering starvation problem. Thanks Bill Quote Link to comment Share on other sites More sharing options...
mark Posted September 7, 2004 Share Posted September 7, 2004 In my experience and I'm sure others will disagree with me but, I tried the sump and still had fuel starvation at a quarter of a tank or less. I'm running and lt-1 with heads and cam, sounds similar to what you will have. I ended up with a surge tank and a secondary pump to feed the surge tank. I can run the tank dry with no fuel starvation problems. As a reference this car is used for weekend drives and lots of track days. Mark Quote Link to comment Share on other sites More sharing options...
Zoldman Posted September 7, 2004 Author Share Posted September 7, 2004 Mark, Thanks for the fast input; I just knew someone would steer me back to the surge tank idea Nothing is ever simple.......... OK, so you still had the problem, and the surge tank fixed it. If I remember correctly, you can use the steel evap tank for a surge tank and feed it from the main tank with a low pressure pump, correct? Does this mean that the low pressure pump is running constantly? I have one of those setups on another car, and the noise gets old after awhile. I guess if you get real quiet pump, it would be alright. How does your sound? Can you give me the step by step or a schematic on what you did, and what pumps you used? I get the concept, but where the return line goes and all that is not real clear. I only want to do this once, and your experience would be much appreciated. Thanks again, Bill p.s. What kind of track running are you doing? Quote Link to comment Share on other sites More sharing options...
Dan Juday Posted September 7, 2004 Share Posted September 7, 2004 Just so we compare apples and apples... I have a sump and have no starvation problems. But, I did not cut out the bottom of my tank. I drilled holes so that the bottom of the tank would act like a baffle keeping the fuel in the sump. If Mark did this as well and still had starvation problems than no argument from me. Do the surge tank. Quote Link to comment Share on other sites More sharing options...
Zoldman Posted September 7, 2004 Author Share Posted September 7, 2004 Dan, Yeah, I was surprised that Mark still had the prob, even with the sump, but if you just cut one big hole, half of what was in the sump would slosh out right away, and defeat the whole purpose. What kind of ground clearance do you have with your sump? Is it the typical 3" deep unit sold at Summit and Jegs? I really like the sump idea, just having a hard time envisioning what might happen with that thing hanging down there. I guess you can run the lines up and over the tank and that would help. Thanks Bill Quote Link to comment Share on other sites More sharing options...
mark Posted September 7, 2004 Share Posted September 7, 2004 I just had a sump in the tank, no holes to baffle. It was OK on the street but on the track (road course) I had to run over half a tank for a good run and below a quarter it was horrible, only ran in the straights. For the surge tank I used the mothod in the JTR manual. Secondary pump runs all the time but I can hardly hear it over the exhaust Lines run as follows, tank outlet to secondary pump to inlet on surge tank (at the top of the tank) outlet from the bottom of the surge tank to the fuel injection pump, to fuel rail on lt-1, return line from fuel injection rail to surge tank, return line from top of surge tank to the return line in the main tank. Hope that helps If the car was not used on the track I think I woould have been OK without the surge tank. Mark Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted September 7, 2004 Share Posted September 7, 2004 Mark, do you have any pictures of your setup? !M! Quote Link to comment Share on other sites More sharing options...
mark Posted September 7, 2004 Share Posted September 7, 2004 Sorry, No pics and the car is running well and hopefully will continue to do so. If I have a need to pull the cell out again, I'll take some pics. Mark Quote Link to comment Share on other sites More sharing options...
Dan Juday Posted September 8, 2004 Share Posted September 8, 2004 Got my sump from Jeggs. It is 2 1/2" deep and I have 9" of clearance from the bottom of the sump to the ground but I'm not running the stock fuel tank. Quote Link to comment Share on other sites More sharing options...
wheelman Posted September 8, 2004 Share Posted September 8, 2004 Zoldman, Here is a picture of a sump produced by Brad Davies. He is a member here. He says it's 240Z specific but it might work with an early 260 tank. The sump is very low profile and only hangs down about 1 to 1.5 inch(s) below the tank. His email is Brad_Davies@omniglass.com. Shoot him an email and find out if it will work with your tank. I bought one for my 240 and the quality is top notch. He will put whatever fittings you want on it. I had him put one in each corner so the fuel can run to either side and still be picked up. He charged me $60.00 plus shipping. Wheelman Quote Link to comment Share on other sites More sharing options...
Zoldman Posted September 8, 2004 Author Share Posted September 8, 2004 Wheelman, Now that's what I'm lookin' for!!! I emailed Brad just now; hope the early 260 tank is similar enough that his unit will work. Low enough profile to keep me from getting nervous, and should do the job just fine. Looks well made, too. Thanks for the help Bill Quote Link to comment Share on other sites More sharing options...
Clifton Posted September 12, 2004 Share Posted September 12, 2004 I used a factory in tank sump and fuel pump from a Toyota Supra. This is on a 240 tank. I have no issues even when below the line just above the "E". Quote Link to comment Share on other sites More sharing options...
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