View Full Version : Diesel return line
I'm just now getting to put in 2.8TGV diesel in my 110 (special thanks to Dave Marchand for his pictures of his install, which helped answer a lot of questions when we got stuck!)
I'm considering putting in two auxiliary fuel tanks. Each would be between the frame and the body in the rear, behind the wheels in that dead space in the wheel arch. They both would connect via a big hose into the main tank so filling would be from the standard filler hole, through the first tank, into the main tank and when that's full the saddle tanks would fill.
This seemed like a good idea until I remembered the return line. I believe the top most point (pretty much the filler hole or slightly above) would be higher than where the return line connects to the engine. I'm assuming this would mean there would be fluid flow in the WRONG direction along the return line, if I attached it lower. This would be bad. I also don't know if the return has any pressure to push it uphill to the filler.
I'm trying to think of some way around it and was wondering if anyone had input. Maybe the return line is under pressure enough to lift it up to the filler hole height? If so, then it's not a problem.
One thought I had was just having it drain into the tank under the passenger seat (which isn't installed right now). This tank has a fuel gauge so I can see when it's filling and then pump that back to the main tank.
I know none of this is really needed, but if set up well it'd mean a no brainer way to get 40 gallons of onboard fuel and about a 1000 mile highway range from a 110.:luxhello:
12-12-2006, 03:55 PM
I don't know how the return lines work on a defender, most old diesels have a number of return paths that all join to together. Mine have returns from the filters, the injection pump and the unused fuel from the injectors. The return line is not intended to be under pressure (although some of these return paths do have pressure) and it is usually sized such that you cannot build pressure in the return line and the fuel flows via gravity to the tank.
If you were to move the return line to the filler neck, can it still flow under gravity? If so nothing has really changed. I am not sure if a pressurized return line would have any unwanted consequences such as affecting fuel delivery.
12-12-2006, 10:59 PM
Thanks for the shout out PWC. If I'm understanding you correctly, you are going single filler neck for both tanks? I use an aux pump to pump from my saddle tank to my main tank. The return line is plumbed to the top of my tank. Basically, any overflow goes between the two tanks but never reaches high enough to the fillers (I have two).
12-12-2006, 11:58 PM
Don't think you'll have any trouble. I have a large tank (30gal) in the stock location and both the return and draw lines are below the full level of the tank. They are in the stock location as well. The tank just stays on full (on the guage) for a long time before drawing down. I have also installed a saddle tank in the rear 1/4 panel of a 110 (in the location you are mentioning). It is a pass though between the filler and the tank, and the return line was still in the stock location. That worked great.
These were both 300tdi machines, but the 2.8 should be the same.
There is a company in South Africa (Excel tanks) that makes kits for the rear 1/4 panels of defender 110s. You can get fuel for one side and water for the other. Increases fuel capacity from 22gal to around 30gal.
Dave, yours is set up the way mine used to be, exactly. What I'm adding in now is a higher third and 4th tank, if you will, to the rear quater panels. I still envied your install with the shop you had and taking the body off. Everytime we'd have a positioning question (like the air filter and which side the clamps went on) and I took someone new over to the computer they'd just say "yeah, you shoulda done it that way. that looks easier". We did have good fortunte with all the mounts meeting up perfectly though.
Graham, so in the 300TDI setups you had, the fuel level was likely at times (when full) above where the fill is?.......ok, I think I answered my own questino after going out the garage. Indeed, if the return is the line that comes off the injectors and then terminates in a fitting just above the injector pump, then that is above where the tanks in the rear would be. Awesome. Thanks for the reassurance that it's worked before. I'll check out the company you mentioned, and what did you do a for your 30gallon tank in the standard location? Since switching to diesel, I'm a bit obsessed with getting as much range into the truck as possible and as close to the frame as I can.
12-13-2006, 12:25 PM
Glad I could help through cyberspace! I guess a picture is worth a few hundred words...
So it sounds like you didn't have to change or move any body mounts on the 110? Now THAT is interesting. You are using the M&D kit correct? Maybe I need to hurry up and get a 110 if that is the case!
Funny enough, one of the Brittanica 2.8's showed up on ebay (not sure how it is titled):
P.S. Your mileage should be pretty good. After break in, get Pendy to help you with some pointers on changes to the fuel delivery. I've had pretty good success squezzing power out of mine without any bad effects (changes to smoke screw, fueling, boost, etc). I'm awaiting a full size intercooler at the moment!
Also, make sure you don't overfill the oil in the sump prior to startup.
Also, make sure you don't overfill the oil in the sump prior to startup. Yeah, I remember that thread. Learn from the mistakes of others, I always say. :)
We were amazed we didn't have to move the mounts either, especially after we removed them!! :Wow1: Everything I had read stated they needed to be moved. I used this picture (http://www.pbase.com/dmarchand/image/34191116)of yours to line it up. See the two fins coming off the spring/shock mount and the edge of the engine mount lines up with the rearmost of those? that is the spot my mounts are in. Had I looked at your picture, I wouldn't have cut them off in the first place. They worked perfectly there. We put in the extra slot on the rear tc/tranny mounts as mentioned in the instructions from David Jackson/M&D and it all lined up.
Sure enough, the t-case shifter is about 15mm more forward like the rear mount holes that were added. Goofy. Felt pretty stupid for cutting off the mounts and welding them back in the same spot. But you live and learn.
I do plan on running it with the factory settings for a while so when I tune things up a little I can notice if there's a big or little difference. I don't know if you're on the Yahoo group, but Terry there had turned his up and was asking for the factory spec on the star wheel. I measured mine out to 24.55mm (http://www.northwestoverlandsociety.org/Blogs/tabid/264/EntryID/8/Default.aspx) in case you ever need that number.
12-13-2006, 09:03 PM
Nice, that is very interesting and good news. Helps me make my case for a 110 to the little lady.
Thanks for the measurement. When I pulled mine, I marked everything in paint stick. But in hindsight, I realize that probably did not work very well. I need to mess with my smoke screw a little more but haven't found the time.
I recently put in the LR choke/throttle holder. If you are even considering putting one in, you should drill the hole now in the arm that supports the accelerator cable just before the throttle body. I can take a pic if you like. Biggest pain getting in there after the fact, especially with the AC compressor in the way.
Why did you go with the LR throttle holder?
I noticed your AC compressor is different than mine. I got the wrong pulley for mine and need to hit up David about that. The one he sent me was splined and the one i took off is keyed. I noticed your connectors are on the side as opposed to mine on the back (which will make it a pain to adjust things later). Got any clue about compressors? As it is, I damanged the shaft when removing, so I'll probably just replace the unit. But it's still winter. :)
12-14-2006, 01:07 AM
Graham, so in the 300TDI setups you had, the fuel level was likely at times (when full) above where the fill is?
Not above the fill, but above the return. But I think you got that already. The tank I got is stainless from WVM holdings in the UK. It is a cavernous tank, but has some big problems. It sticks down far enough to be a departure angle killer. I have scraped mine in various places (see pic). The Excel solution is to keep the stock tank and add a stainless tank in the wing. It gets about the same capacity as mine and also keeps the departure angle as stock. It is a really nice solution.
I have a new excel tank in its box in my garage. I was thinking of trying to use it in my truck, to get the departure angle back, but may not be able to. My truck, being a TD5 chassis, came with a plastic tank and with the TD5 tank draw assembly which isn't the same as the 300 one. If you are really interested, I could probably sell it, but you won't like the price! (I paid $500 for it!)
The 3rd pic below is of the water tank in the drivers side wing.
12-14-2006, 01:19 AM
Okay, this isn't the best pic of the excel tank installed but you can see the bottom of it in the wing. The black tab on the bottom is for mounting a mud flap.
12-14-2006, 01:28 AM
Wow, that is a huge tank.
Peter, the compressor is the 300tdi stock version. I went through a saga with the whole AC thing and am still sorting some of it out. Basically everything they sent was wrong, specifically the brackets. Could never get the right one so I ponied up for the stock version from RN. Anyway, did the trick. The remainder of the sorting out has come from trying to jam a full size rad, full size intercooler, auto trans cooler and the ac condensor into the stock d-90 grill. Luckily, the 110's have the extended grill so you have no concern on that. I'm sure Pendy can give you the synopsis and he's been terrific about working it all out long distance.
Yeah, that tank does kill the angle. I have enough problems with hitting the rear step that I don't need something lower than that. :)
I might be interested in the tank you have. I'm a sucker for things that make my life semingly easier but I can really live without. Do you have any info on them? The only thing I find when I google them is your website.
I'll have to talk to David about it since it's not going to work, and we even went over the model it was to the point where I sent him pictures to make sure it was the right one. I got a new, different transmission cooler from Pendy and am still figuring out the best place to mount it. It's bigger than the one that was there before but it might all fit. It might fit underneath though.
12-14-2006, 03:01 AM
Do you have any info on them? The only thing I find when I google them is your website.
Back in 2003 I found a web site with all the excel tanks and instructions and everything. Now I can't find it for the life of me. I got mine from Hannibal USA in LA. I'll keep looking for info on them
12-14-2006, 01:26 PM
I had good luck with a local guy who builds aluminum tanks for boats here on the seacoast. If excel doesn't pull through, you might give a call to any local boat builders. The fabricators they have are always amazing and usually are not that expensive.
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