Aux fuel pump

[Niehart]

Good write up Don, could save some folks serious time on their mounting and plumbing.

Sure do like this stuff, can't wait to see the mounting hardware Justin and his friend are building.

 

[Justin]

Weird. None of the icons at the top are active.
Justin, it sounds like you know what you're doing, so not sure how much this link will help. Just in case, though, here's my write-up of when I did mine.

https://candybuttorg.ipage.com/cba/node/90

D

Nice write up Don. I pretend I know what I'm doing, but I learned most of it from reading web pages like yours :lol: .

Finished up the tank portion this morning. Here's the finished product.

Will have the mounting bracket done by next Saturday. Off to the store to by some heat shield and Loctite 567 so I can button it all up.

 

[Justin]

Plumbing is all done. Now just waiting on the bracket for the tank.

 

[Justin]

Got it all together today. My friend Gary did an awesome job with the mounting plate. Slides in like the stock rear seat, and two bolts hold the front down.

Tank on, figuring out the final plumbing bits.

Valve is right behind my butt on the clutch side - easy to reach by feel.

Stock truck has plenty of clearance.

$10 walmart duffel bag with the bottom cut out to make it look pretty.

Off for a test ride. Will post up the results.

 

[Niehart]

Thanks for the update.

Keep us in the loop.

 

[Justin]

Looks like I won't need a pump after all. The main gas tank was at the very bottom of 3 bars (i.e. 2 bars on the side stand, when you stand up it goes to 3 bars). I put 10 dollars in the aux tank, so 2.7ish gallons. I took 10 minutes to go up one full bar on the gas gauge (4 bars), then the 2nd bar took 15 minutes (5 bars). From there it held steady at 5 bars, which seems right with gas usage, versus only putting 2.7 gallons in the aux tank. I suspect if the aux tank was full, and I waited till 1 or 2 bars, it would flow faster. But, it seemed to be fine at 75 mph on the highway. Factoring in the usage at that speed and going up a bar every 10-15 minutes I think it would be hard to outrun the gas flow.

 

[Specter]

I have a similar mounting setup and go with gravity feed. Normal process for me is to go about 100 miles, then open the valve for a few minutes (one song on the radio). to bring the level of the aux tank down so it doesn't expand and dump any fuel. Then go to 190 miles,( equals approximately the range of my aux tank) open the valve, and leave it open until the next fuel stop.

By transferring early, you don't have to worry about burn rate vs fill rate, and the fuel pump is always well submerged, keeping it cool. Running any tank nearly dry is hard on internal fuel pumps, as they rely on the fuel for cooling. I've never had any draining issues.

I also recommend doing the ball-ectomy to the fuel cap, and keeping it and all the overflow and vent lines clear and clean,

 

[Justin]

Yeah, I'd never let it run out before switching the aux on. When it drops to one bar, there should be at least 2 gallons still in the tank. Heck, I ran on reserve for 50 miles before I pulled the tank to do the welding. Still had to syphon like a 3rd of a gallon out.

I did another test last night. Put 3 gallons in the aux. Waited till it was at one bar. Switched on the aux. Took two minutes to go back up to 2 bars, 5 minutes to go 3 bars, and 8 minutes to go to four bars. So, I'm pretty comfortable with not outrunning the fuel supply.

 

[dcarver]

Just remember it is 2x more embarrassing to run out of fuel when you have an aux tank........

 

[101stpathfinder]

+1

And 3 times more embarrassing with an aux tank in the IBR. Actually it was a transfer issue- but still on the side of the road at 0 mph.

 

[fljab]

I went round and round trying to get my aux to feed as a gravity. In the mornings it was fine, when it got hot then no-go. I got good at reaching into my jacket for the spare key, opening the main tank cap, and reaching behind and opening the aux tank cap. Still no-go. I solved it with an aux pump. Many use the NOS version at ~$100; I had a spare low pressure Purolator/Facet square "cube" pump that has now gone ~60K miles with no issues. These look to go for ~$65ish on Ebay.

https://www.facet-purolator.com/cube-fuel-pumps.php

https://www.ebay.com/sch/eBay-Motors-/6000/i.html?_nkw=facet+fuel+pump&LH_PrefLoc=1

One more thing - when I first installed it I just did a simple on/off switch that I mounted off the cell behind me near the valve. I'd reach back, turn on the switch and valve and watch the fuel level rise. I found I was leaving it on, sometimes for a couple of hours until I slowed down at an exit. I've had no problems - same pump so convinced of the reliability - but it bugged me. So, I took a 15 min lamp timer and routed the neg wire through it and put on the dash. So now, I reach back, turn on valve and switch, and reach up and turn timer on to 10 min (it takes ~8 min to drain tank).

https://www.ebay.com/itm/Intermatic-FD15MWC-15-Minute-Spring-Loaded-Wall-Timer-White-/350854341521?pt=LH_DefaultDomain_0&hash=item51b08c6391

I'm going to rehab all my electric farkle controls this winter, but until then, this works good and was very simple to do.

 

[Chuck35]

Automotive rear window defroster relays are timed. Momentary contact to energize and they run around 15 minutes.

I could see this being useful for a transfer pump, perhaps even triggered by opening the valve.

 

[fljab]

Automotive rear window defroster relays are timed. Momentary contact to energize and they run around 15 minutes.I could see this being useful for a transfer pump, perhaps even triggered by opening the valve.

Thanks Chuck, good info. I wasn't sure how to attack the timer issue and the lamp timer was easy, but I do get alot of Qs on the road about what that is. I usually tell them it's for the little pizza oven below it - which is my Legal Speeding waterproof V1 box.

I'll take a look at the factory window defroster relays.

 

[Justin]

Just a 12v timer relay, cheap and adjustable. https://www.ebay.com/bhp/12v-timer-relay

 

[Justin]

Well, final flow test yesterday. 4.5 gallons in the aux tank, and waited till the reserve bar started flashing. Took just a minute to get out of reserve (back to one bar), 2 minutes to two bars, 3-4 minutes to three bars, 6 minutes to four bars. So, in less than 15 minutes I easily transfered 2.5 gallons, would have to be going pretty fast to outrun that lol. Past there it starts to slow down as the fuel levels balance out. After an hour riding it was up to 7 bars. I am quite confident flow will not be an issue. Case closed.

 

[Niehart]

Justin, If you happen to get one of those toaster days [hotter then hell] it would be interesting to see if the numbers are the same.

 

[Justin]

Justin, If you happen to get one of those toaster days [hotter then hell] it would be interesting to see if the numbers are the same.

Yeah - It's been nice here, so didn't get a chance to test under those conditions. Hope I don't find out the hard way during the Big Sky rally next week!

 

[dcarver]

it will be fine..