Oddmanout84 Posted May 14, 2011 Share Posted May 14, 2011 (edited) Excellent looking fuel line routing. This is EXACTLY how I planned to run mine. The only problem for me was that I couldn't get a hold of some 5/8 SS from Summit, so I ended up ordering the same size in aluminium. We'll have to see how that goes... I'm also running the A1000 fuel pump. It would be interesting to see where you plan to mount yours. The plan I have for mine is to make a low hanging cradle out of 1/8" steel bar welded to the front of the stock fuel tank, just about level with the bottom of the tank so it's not hanging *too* low. Edited May 14, 2011 by Oddmanout84 Quote Link to comment Share on other sites More sharing options...
rossman Posted May 14, 2011 Author Share Posted May 14, 2011 (edited) Excellent looking fuel line routing. This is EXACTLY how I planned to run mine. The only problem for me was that I couldn't get a hold of some 5/8 SS from Summit, so I ended up ordering the same size in aluminium. We'll have to see how that goes... I'm also running the A1000 fuel pump. It would be interesting to see where you plan to mount yours. The plan I have for mine is to make a low hanging cradle out of 1/8" steel bar welded to the front of the stock fuel tank, just about level with the bottom of the tank so it's not hanging *too* low. Thanks! I still have to run the 1/2" tube. It's going to have a few more bends as I plan to run it all the way up to passenger side strut tower where the pressure regulator is mounted. I purchased the tube from a local industrial supply shop. Today I picked up some 6" x 1/8" flat stock steel to make my pump mount. I'll take some pictures of the pump mount when I get around to fabricating it. Edited May 14, 2011 by rossman Quote Link to comment Share on other sites More sharing options...
TimZ Posted May 17, 2011 Share Posted May 17, 2011 Rule of thumb is to size the supply line to the fueling requirements of the engine, and size the return to the flow capacity of the pump. Said another way... the return would always be at least the size of the supply, and often larger. Sorry for the late reply, but I think you meant this the other way around (?) The supply has to handle the entire flow of the pump, but the return only has to has to handle the difference between what the engine needs and what the pump is putting out. In other words the return will never need to flow more than the supply. In the absolute worst case they would flow the same. Quote Link to comment Share on other sites More sharing options...
UofA_ZCar Posted May 17, 2011 Share Posted May 17, 2011 (edited) From what I have read you always want the return at least as big (if not bigger) than the supply line because you want the return to be as close to zero pressure as possible. It also seems to me that both the engine requirements and the pump would factor into the size of the feed lines. Edited May 17, 2011 by UofA_ZCar Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 17, 2011 Share Posted May 17, 2011 I have NEVER seen a return line sized larger than the feed line. Sizing the feed line large minimizes pressure drop and fuel pump overworking. Oversizing the return line just costs more money I guess. I haven't seen many issues with undersized return lines causing a problem other than at idle (for instance L28ET's trying to run the -3 return line on the stock 240!) Return line flow will ALWAYS be SMALLER than supply line flow, hence it will always be smaller! Quote Link to comment Share on other sites More sharing options...
rossman Posted May 17, 2011 Author Share Posted May 17, 2011 (edited) If you look at Aeromotive's A1000 installation instructions you will find that they recommend -10 fuel line from the tank to pump to fuel rail to pressure regulator then -6 fuel line from the bypass back to the tank. That setup is reflected in the A1000 regulator: -10 input and -6 bypass. I'm going to run -10 all the way to the regulator (post fuel rail) and plug the remaining -10 input hole. For the return I'm using 1/2" tube so have a -6 to 1/2" tube adapter. Edited May 17, 2011 by rossman Quote Link to comment Share on other sites More sharing options...
rossman Posted May 17, 2011 Author Share Posted May 17, 2011 I forgot to mention that I'm also running their pump speed controller so the pump will be running 1/2 speed at idle and low load situations. Hopefully this will also help reduce noise associated with the pump. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted May 17, 2011 Administrators Share Posted May 17, 2011 I have NEVER seen a return line sized larger than the feed line. Have a look at some small block Chev's. I believe you'll find the LT1, LT4, and L98 run a 5/16" supply and 3/8" return. I'm betting you could find a few more GM vehicles with that scenario. I forgot to mention that I'm also running their pump speed controller so the pump will be running 1/2 speed at idle and low load situations. That should allow for a smaller return line. Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 18, 2011 Share Posted May 18, 2011 Do cars have return lines any more? Last late-model I looked in, didn't HAVE a return line. That GM scenario I will have to check into, it seems aberrational, and I'm sure there is some GM-Logic behind it. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted May 18, 2011 Administrators Share Posted May 18, 2011 You're aberrational Quote Link to comment Share on other sites More sharing options...
TimZ Posted May 18, 2011 Share Posted May 18, 2011 Do cars have return lines any more? Last late-model I looked in, didn't HAVE a return line. That GM scenario I will have to check into, it seems aberrational, and I'm sure there is some GM-Logic behind it. Many, if not most, of the new fuel systems are returnless. As I recall they modulate the pump to control the rail pressure. I believe that this is done to reduce evaporative emmisions (ULEV requirements are pretty tough), although is does probably have some slight weight advantages too. Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 18, 2011 Share Posted May 18, 2011 yep, it's an EVAP thing, not having fuel at 140+ F in the tank (go measure it out here sometime!) helps with captive emissions. I'm just being aberrational with the comment... Quote Link to comment Share on other sites More sharing options...
rossman Posted August 15, 2011 Author Share Posted August 15, 2011 (edited) I've just about finished up the piping. The only problem I see now is the fuel filter placement. Unfortunately it was an after tought . It looks to be positioned too far to the drivers side, past where the fuel rail will be located. Since the engine is out I don't have a good reference. I could put a 180 fitting on the end of the filter and come back to the fuel rail...but I don't know if that will work. Any ideas? Edited August 15, 2011 by rossman Quote Link to comment Share on other sites More sharing options...
Oddmanout84 Posted August 17, 2011 Share Posted August 17, 2011 I've just about finished up the piping. The only problem I see now is the fuel filter placement. Unfortunately it was an after tought . It looks to be positioned too far to the drivers side, past where the fuel rail will be located. Since the engine is out I don't have a good reference. I could put a 180 fitting on the end of the filter and come back to the fuel rail...but I don't know if that will work. Any ideas? Since I made my other comment, I've run most of my fuel line. When I got to the point of bending to fit my fuel filter in that location, I decided against it for that same exact reason. Instead, I ran the feed and return lines toward the battery tray. They're both going to be oriented vertically directly to the left of that raised vertical ridge in the firewall (in your first pic). I figured that way I'd have more room for the soft line connection to the fuel rail, which adds a little bit more in the way of flexibility to compensate for engine movement. That, and I figured if I ever did a swap to the RB, the locations of the lines would be on the "correct" side of the engine. I don't know if that's an option for you though, unless you want to start over. I'd say if anything else you could use your current situation to your advantage and make a large "loop" of soft line that might make for decent movement stress reduction. I'm no expert though, as this is also my first rodeo. You've made some beautiful bends in your lines, I'm impressed (and jealous!). I've been cursing the anodized 1/2" aluminium lines I purchased from Summit almost the whole way. Any small touch from tooling causes big, nasty gouges that expose the raw metal. I spent a few hours grinding and polishing my bending tool to help this, but it only worked marginally. As a consequence I took advantage of the softness and bent each line slowly by hand anywhere that doesn't require an angle 45 degrees or greater. Quote Link to comment Share on other sites More sharing options...
rossman Posted August 17, 2011 Author Share Posted August 17, 2011 I'm leaning towards leaving it as-is and looping the hose around with a 90 at the fuel rail. Quote Link to comment Share on other sites More sharing options...
UofA_ZCar Posted September 19, 2011 Share Posted September 19, 2011 Nice work, I'm in the process of putting in new fuel hard lines also. I'm interested ti see how you mount the fuel pump. Quote Link to comment Share on other sites More sharing options...
BlueStag Posted September 19, 2011 Share Posted September 19, 2011 Long term, this is a great thread for me, as I hope to swap away from my 2.6 with SUs to a 2.8 Turbo. Trick is? I am running it all in a '73 Triumph Stag, which never say fuel injection. I assume that I will at some point need to pull the fuel tank out (again, it has been boiled and sealed in the past) to have one or two fittings brazed in. AFTER being boiled out again, of course..... Is stainless steel tubing REALLY necessary? It must be pricey. Aluminum is not available for much less, yet impervious to rust? Aluminum cannot take the pressure, which really is not that high? Honestly, when I set my Stag up for the Z engine, I just used brake line. Not that it sees much pressure at all. Quote Link to comment Share on other sites More sharing options...
rossman Posted September 19, 2011 Author Share Posted September 19, 2011 Nice work, I'm in the process of putting in new fuel hard lines also. I'm interested ti see how you mount the fuel pump. Thanks! I have the fuel pump mounted to my MMS rear LCA brace. I'll be sure to take some pictures one I get the car back on stands. Quote Link to comment Share on other sites More sharing options...
rossman Posted September 19, 2011 Author Share Posted September 19, 2011 Is stainless steel tubing REALLY necessary? Nope. The copper-nickle alloy mentioned is a good alternative. It must be pricey. I paid $50 for a 20 ft stick of ASTM rated 1/2" 316SS tubing. 5/8 was $100/stick. Aluminum is not available for much less, yet impervious to rust? Aluminum cannot take the pressure, which really is not that high? Aluminum would probably work. Quote Link to comment Share on other sites More sharing options...
rossman Posted September 19, 2011 Author Share Posted September 19, 2011 I forgot to mention that I switched shifter mounts. The one pictured above is a McKinney Motorsport mount. I swapped it with one that 240hoke sells. There is now quite a bit more clearance between the mount and the fuel lines. I'll take a picture of it when I get a chance. Quote Link to comment Share on other sites More sharing options...
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