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| Fuel tank question [message #246744] |
Mon, 07 April 2014 23:22  |
BRDRVR
Messages: 184
Registered: July 2013
Location: Clearwater, FL-Gerlach,NV
Karma: 8
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Senior Member |
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Im getting ready to redo fuel lines on 6 coaches. I have done some partial line repairs on some units last summer but have never done all of them. I am thinking of pluging the original Onan supply tube and instead drawing genny fuel off the main tank supply. Eliminating the selector valve and only fueling the coach off of the auxiliary tank. My reasoning is that it increases the potential fuel available for the Onan and still leaves a reserve in the aux that the genny cant burn. By my estimation that increases the potential fuel to the genny by 6 gals. Is my thinking flawed? Also does anyone know where I might but fuel line on spools larger than 50'?
Thanx. David
David Gourdine
http//www.blackrockdesertrvrental.com
booking@blackrockdesertrvrental.com
727-657-1955
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| Re: Fuel tank question [message #246761 is a reply to message #246744] |
Tue, 08 April 2014 09:51  |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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| BRDRVR wrote on Tue, 08 April 2014 00:22 |
Im getting ready to redo fuel lines on 6 coaches. I have done some partial line repairs on some units last summer but have never done all of them. I am thinking of pluging the original Onan supply tube and instead drawing genny fuel off the main tank supply. Eliminating the selector valve and only fueling the coach off of the auxiliary tank. My reasoning is that it increases the potential fuel available for the Onan and still leaves a reserve in the aux that the genny cant burn. By my estimation that increases the potential fuel to the genny by 6 gals. Is my thinking flawed? Also does anyone know where I might but fuel line on spools larger than 50'?
Thanx. David
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David,
That idea would be a disaster to anybody but You and Your operation. That would give you about a 37 gal main engine fuel and/or 37 gal of APU fuel but a 12 gal that the APU can't use. That sounds better for your operation than the OE design. The fill system does confuse the issue.
Adding a separate fill for the rear tank might make things even easier, but that would have to be a MAJOR PITA to include as there really is no room.
Another little discussed issue is the lube oil consumption of the APU. With that much fuel available, that could become a serious consideration.
As to fuel line, I know that Gates has large spools available for some customers, so you could do well if you contacted them directly. 25foot was the common spool at NAPA, but we used to bring in 100 or larger. You will have to get a hold of a real rep as it was sold by part number only.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: Fuel tank question [message #246783 is a reply to message #246761] |
Tue, 08 April 2014 12:59 |
BRDRVR
Messages: 184
Registered: July 2013
Location: Clearwater, FL-Gerlach,NV
Karma: 8
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Senior Member |
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Matt. That is what I thought. By looking at
http://gmcmotorhome.info/tank.html
It would appear to me that if the Onan sucked all the available fuel that the aux tank would still be filled to the bottom of the fill tube. Any fuel added at that point would be diverted the the rear tank as it was added. An example would be the genny ran out of fuel and 5 gals were added by a gas can. As its filled some of the fuel would fill the front tank but over a couple hours that 5 gals would migrate to the rear? Oil consumption is monitored daily and all the control boards and low oil sending units are being, or have been, replaced with Dinosaur boards. I strive to keep the units as original as possible but the added fuel available to the onan is a huge benefit and removing the option of hippies having to understand the fuel selector switch is a plus.
Contacted a gates rep and got the info on low pressure line.
NAPA # (note may be up to 3 pcs w/ no pc shorter then 50')
1/4 H190 250' @$1 per foot
3/8 H191 250' @$1 per foot
5/16 H192 250' @$1 per foot
Thanx for the info
David
| Matt Colie wrote on Tue, 08 April 2014 10:51 |
| BRDRVR wrote on Tue, 08 April 2014 00:22 |
Im getting ready to redo fuel lines on 6 coaches. I have done some partial line repairs on some units last summer but have never done all of them. I am thinking of pluging the original Onan supply tube and instead drawing genny fuel off the main tank supply. Eliminating the selector valve and only fueling the coach off of the auxiliary tank. My reasoning is that it increases the potential fuel available for the Onan and still leaves a reserve in the aux that the genny cant burn. By my estimation that increases the potential fuel to the genny by 6 gals. Is my thinking flawed? Also does anyone know where I might but fuel line on spools larger than 50'?
Thanx. David
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David,
That idea would be a disaster to anybody but You and Your operation. That would give you about a 37 gal main engine fuel and/or 37 gal of APU fuel but a 12 gal that the APU can't use. That sounds better for your operation than the OE design. The fill system does confuse the issue.
Adding a separate fill for the rear tank might make things even easier, but that would have to be a MAJOR PITA to include as there really is no room.
Another little discussed issue is the lube oil consumption of the APU. With that much fuel available, that could become a serious consideration.
As to fuel line, I know that Gates has large spools available for some customers, so you could do well if you contacted them directly. 25foot was the common spool at NAPA, but we used to bring in 100 or larger. You will have to get a hold of a real rep as it was sold by part number only.
Matt
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David Gourdine
http//www.blackrockdesertrvrental.com
booking@blackrockdesertrvrental.com
727-657-1955
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| Re: Fuel tank question [message #246792 is a reply to message #246744] |
Tue, 08 April 2014 15:13 |
lqqkatjon
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
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Senior Member |
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I could be thinking wrong...
but simple thing, would be to remove the selector valve and install a T fitting?
and then unscrew the drain on either tank of your choice, and install a barbed fitting and pipe that to the generator?
The engine would then pull from both tanks, and have the ability to run the tanks bone dry.
but the genset can run all but the 6 gallon reserve?
my only wonder, is if the engine would suck air from a completly dry tank, and cause vapor lock.
the other alternative, would be to install two barbed fittings into the drain ports. 1 to the engine, and 1 to the genset?
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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| Re: Fuel tank question [message #246799 is a reply to message #246792] |
Tue, 08 April 2014 16:29 |
BRDRVR
Messages: 184
Registered: July 2013
Location: Clearwater, FL-Gerlach,NV
Karma: 8
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Senior Member |
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The event that these units house attendees if off road. For the most part it flat desert but there is a 1/4 mile section of road once you leave the pavement. Depending on conditions it can get a little rough. The danger of one of those lines getting snagged and ripped off and dumping 30 gals of fuel of BLM land isn't a chance I can take. The coach only has to run 13 miles out there and 13 back plus up to 10 hrs idle time. But the extra 12hrs of fuel for the APU is a bonus. It looks like all i have to do is adapt a 1/4 inch reducer to that supply tube and eliminate the tank selector. | lqqkatjon wrote on Tue, 08 April 2014 16:13 |
I could be thinking wrong...
but simple thing, would be to remove the selector valve and install a T fitting?
and then unscrew the drain on either tank of your choice, and install a barbed fitting and pipe that to the generator?
The engine would then pull from both tanks, and have the ability to run the tanks bone dry.
but the genset can run all but the 6 gallon reserve?
my only wonder, is if the engine would suck air from a completly dry tank, and cause vapor lock.
the other alternative, would be to install two barbed fittings into the drain ports. 1 to the engine, and 1 to the genset?
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David Gourdine
http//www.blackrockdesertrvrental.com
booking@blackrockdesertrvrental.com
727-657-1955
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| Re: Fuel tank question [message #246829 is a reply to message #246799] |
Tue, 08 April 2014 20:46 |
cbryan
Messages: 451
Registered: May 2012
Location: Ennis, Texas
Karma: 3
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Senior Member |
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David,
I run currently with the selector bypassed. It only runs out of gas once. Then, it's more gas or get under and squeeze shut a gas line with vise grips.
To state it a different way, if one pickup is above any remaining gas, the coach is out of gas, no matter what the second tank holds. It means that you are carrying around 12 gallone you can't use. I am planning to use two fuel pumps in place of the selector valve. One goes dry, switch to the other one and drive on a while. I plan to change that situation.
Not practical for your situation, I think. Jim Bounds keeps the selector valve and adds an inline fuel pump to the forward tank so it is switched on whenever the forward tank is selected. Maybe the best of both worlds, as you keep the stock fuel pump situation, and if vapor lock looms, just switch to the auxiliary tank. You will then get pressurized gas up to the engine; which pressure inhibits vapor lock. But, those pumps do cost money.
If your selector valves work, consider Jim's solution. You could tee off the main tank, or put the pump on the back tank feed and put the fuel pump there. Makes a little more sense there. Run off the auxiliary until it stops then switch to the main. Doing that keeps the maximum fuel in the main where it is farther from the engine and exhaust heat and stays a little cooler.
Carey from Ennis, Texas
78 Royale, 500 Cadillac, Rance Baxter EFI.
[Updated on: Tue, 08 April 2014 21:47] Report message to a moderator |
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| Re: [GMCnet] Fuel tank question [message #246840 is a reply to message #246783] |
Tue, 08 April 2014 21:25 |
mickeysss
Messages: 1476
Registered: January 2012
Karma: 0
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Senior Member |
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If they have trailer hitches. you could put a basket on the back on the trailer hitch and put a boat fuel tank that goes to the onan
with about 30 gallons and have it's own fuel tank the same fuel pump would work and you could just plug the old fuel line and if you ever wanted to sell them later you could put it back and take the basket off the back. put an extension of the trailer hitch about one foot long past the basket so if it was rear ended it would hit the extension a foot away from the tank and basket.
mic - disney, 77palm beach
On Apr 8, 2014, at 10:59 AM, David Gourdine wrote:
>
>
> Matt. That is what I thought. By looking at
> http://gmcmotorhome.info/tank.html
> It would appear to me that if the Onan sucked all the available fuel that the aux tank would still be filled to the bottom of the fill tube. Any fuel added at that point would be diverted the the rear tank as it was added. An example would be the genny ran out of fuel and 5 gals were added by a gas can. As its filled some of the fuel would fill the front tank but over a couple hours that 5 gals would migrate to the rear? Oil consumption is monitored daily and all the control boards and low oil sending units are being, or have been, replaced with Dinosaur boards. I strive to keep the units as original as possible but the added fuel available to the onan is a huge benefit and removing the option of hippies having to understand the fuel selector switch is a plus.
> Contacted a gates rep and got the info on low pressure line.
> NAPA # (note may be up to 3 pcs w/ no pc shorter then 50')
> 1/4 H190 250' @$1 per foot
> 3/8 H191 250' @$1 per foot
> 5/16 H192 250' @$1 per foot
> Thanx for the info
> David
>
> Matt Colie wrote on Tue, 08 April 2014 10:51
>> BRDRVR wrote on Tue, 08 April 2014 00:22
>>> Im getting ready to redo fuel lines on 6 coaches. I have done some partial line repairs on some units last summer but have never done all of them. I am thinking of pluging the original Onan supply tube and instead drawing genny fuel off the main tank supply. Eliminating the selector valve and only fueling the coach off of the auxiliary tank. My reasoning is that it increases the potential fuel available for the Onan and still leaves a reserve in the aux that the genny cant burn. By my estimation that increases the potential fuel to the genny by 6 gals. Is my thinking flawed? Also does anyone know where I might but fuel line on spools larger than 50'?
>>> Thanx. David
>>
>> David,
>>
>> That idea would be a disaster to anybody but You and Your operation. That would give you about a 37 gal main engine fuel and/or 37 gal of APU fuel but a 12 gal that the APU can't use. That sounds better for your operation than the OE design. The fill system does confuse the issue.
>>
>> Adding a separate fill for the rear tank might make things even easier, but that would have to be a MAJOR PITA to include as there really is no room.
>>
>> Another little discussed issue is the lube oil consumption of the APU. With that much fuel available, that could become a serious consideration.
>>
>> As to fuel line, I know that Gates has large spools available for some customers, so you could do well if you contacted them directly. 25foot was the common spool at NAPA, but we used to bring in 100 or larger. You will have to get a hold of a real rep as it was sold by part number only.
>>
>> Matt
>
>
> --
> David Gourdine
>
> http//www.blackrockdesertrvrental.com
>
> booking@blackrockdesertrvrental.com
>
> 727-657-1955
>
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| Re: [GMCnet] Fuel tank question [message #246841 is a reply to message #246799] |
Tue, 08 April 2014 22:05 |
mickeysss
Messages: 1476
Registered: January 2012
Karma: 0
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Senior Member |
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I would put a cargo carrier on the trailer hitch and run a gas line straight to the onan.
$280 two of these on the back of the trailer hitch = 58 gallons of gas or 116 hours of the onan working. or 5 days straight 24 hours a day. with a/c.
http://www.westmarine.com/portable-fuel-tanks/moeller--24-gallon-topside-fuel-tank--8978397
$50 folding cargo trailer hitch basket.
http://www.pronto.com/compare/500lb-folding-cargo-carrier-luggage-11609955396?pageLocation=ProductTitle
Our this one which you could fill other tanks with it if needed. and have 29 gallons on the rear. or about 3 days at 24 hours on the onan.
http://www.westmarine.com/portable-fuel-tanks/moeller--gas-walker-29-gallon-fuel-transport--7769532
mic, anaheim ca. 77 palm beach
On Apr 8, 2014, at 2:29 PM, David Gourdine wrote:
>
>
> The event that these units house attendees if off road. For the most part it flat desert but there is a 1/4 mile section of road once you leave the pavement. Depending on conditions it can get a little rough. The danger of one of those lines getting snagged and ripped off and dumping 30 gals of fuel of BLM land isn't a chance I can take. The coach only has to run 13 miles out there and 13 back plus up to 10 hrs idle time. But the extra 12hrs of fuel for the APU is a bonus. It looks like all i have to do is adapt a 1/4 inch reducer to that supply tube and eliminate the tank selector. lqqkatjon wrote on Tue, 08 April 2014 16:13
>> I could be thinking wrong...
>>
>> but simple thing, would be to remove the selector valve and install a T fitting?
>>
>> and then unscrew the drain on either tank of your choice, and install a barbed fitting and pipe that to the generator?
>>
>> The engine would then pull from both tanks, and have the ability to run the tanks bone dry.
>>
>> but the genset can run all but the 6 gallon reserve?
>>
>> my only wonder, is if the engine would suck air from a completly dry tank, and cause vapor lock.
>>
>> the other alternative, would be to install two barbed fittings into the drain ports. 1 to the engine, and 1 to the genset?
>
>
> --
> David Gourdine
>
> http//www.blackrockdesertrvrental.com
>
> booking@blackrockdesertrvrental.com
>
> 727-657-1955
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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| Re: [GMCnet] Fuel tank question [message #246846 is a reply to message #246807] |
Tue, 08 April 2014 22:59 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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I started to answer this yesterday with my thoughts and did not do it. Here they are now:
1. I believe Coachman did just exactly what you are suggesting.
2. If you decide to do this make sure your Onan has the electric fuel shutoff valve right before the electric fuel pump on the Onan. This valve prevents the possibility of the coach engine fuel pump sucking fuel air if the flat drops in the Onan carb.
3. The idea of installing a tee between tanks is a bad one. You never want to tee two tanks together if they are located below the level of the engine. If you do, you will suck air from the empty tank while the other tank with the remaining fuel can not be used. If you want maximum endurance, the selector valve or a similar isolation system needs to be preserved.
This can been seen on airplanes. On high wing airplanes with the fuel stored overhead, a "both" position on the fuel selector is normally available. On aircraft with low wings and fuel stored below the engine, there is never a "both" selector position and a back up electric fuel pump is required.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Fuel tank question [message #246900 is a reply to message #246744] |
Wed, 09 April 2014 13:33 |
BRDRVR
Messages: 184
Registered: July 2013
Location: Clearwater, FL-Gerlach,NV
Karma: 8
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Senior Member |
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Im with Ken on teeing or connecting the tanks. For the most part I don't have a problem with the original setup and only have had a few renters that ran out of genny fuel. I have had to "rescue" a group due to them not realizing they had hit the tank selector switch. There are bike racks on the back of most of the and even if there were not spare tanks on the rear would get jostled or stolen. For the most part the Onans are run 3-4 hrs a day for up to 8 days so that extra 6 gals is just the buffer needed to be the difference between making it that last day and running out. It is all about conservation of resources out there and I am just trying to maximize what is already available without major alterations or expense.
David Gourdine
http//www.blackrockdesertrvrental.com
booking@blackrockdesertrvrental.com
727-657-1955
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