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[GMCnet] Fuel Cooking Experiment [message #97919] Tue, 31 August 2010 08:49 Go to next message
Ken Coit is currently offline  Ken Coit   United States
Messages: 151
Registered: November 2005
Karma: 0
Senior Member
No, I didn't use fuel.

Here's the rough results of my cooking experiment:

Using a clay saucer upside down on a gas burner, I created a radiant heat
source with some convection sneak paths. Above the saucer about 3" I placed
a coated wire shelf and on that I set a flat black can filled about 80% with
12 oz. (350 ml) of tap water, covered.

The saucer reached about 350°F at the lowest setting. After more than 10
minutes, the can and water had reached 120°F. This seemed to be a stable
state. While some components of today's fuel might vaporize at that
temperature, to solve the "vapor lock" problem, I think we are looking for a
different source of thermal energy than the road surface or the cooling
system. How about that exhaust system?

Now then, if the exhaust system is heating the fuel to within a few degrees
of vaporization and you add radiant heat to the tank, you could well have a
problem pulling fuel to the pump.



--
Ken Coit, ND7N
Raleigh, NC
Parfait Royale
1978 Royale Rear Bath, 403, 3.07
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Re: [GMCnet] Fuel Cooking Experiment [message #98006 is a reply to message #97919] Tue, 31 August 2010 20:33 Go to previous messageGo to next message
shawnee is currently offline  shawnee   United States
Messages: 422
Registered: February 2004
Location: NC
Karma: 0
Senior Member
Ken Coit wrote on Tue, 31 August 2010 09:49

No, I didn't use fuel.

Here's the rough results of my cooking experiment:

Using a clay saucer upside down on a gas burner, I created a radiant heat
source with some convection sneak paths. Above the saucer about 3" I placed
a coated wire shelf and on that I set a flat black can filled about 80% with
12 oz. (350 ml) of tap water, covered.

The saucer reached about 350°F at the lowest setting. After more than 10
minutes, the can and water had reached 120°F. This seemed to be a stable
state. While some components of today's fuel might vaporize at that
temperature, to solve the "vapor lock" problem, I think we are looking for a
different source of thermal energy than the road surface or the cooling
system. How about that exhaust system?

Now then, if the exhaust system is heating the fuel to within a few degrees
of vaporization and you add radiant heat to the tank, you could well have a
problem pulling fuel to the pump.
--
Ken Coit, ND7N
Raleigh, NC
Parfait Royale
1978 Royale Rear Bath, 403, 3.07




Ken,

If you are interested in reducing radiant heat to the gas tank you might try what I have done. I coated the bottom and the sides of the tanks where I could reach with Super Silver 300 sealant. It is made for roofing but looks good on gas tanks. It is a sealant with what looks like black asphalt and aluminum particles. When you brush it on it looks black, but when it dries it has an aluminum finish. I have never had vapor lock but I thought I would try it anyway. The asphalt sealer gives a little insulation and the aluminum reflects heat radiation. I got the sealant at Lowes hardware in a gallon can. You have to stir it like crazy to get into a homogeneous mixture but it sure looks good on the tanks..


Gene Dotson
74 Canyonlands
www.bdub.net/Motorhome_Enhancements New Windows and Aluminum Radiators
Re: [GMCnet] Fuel Cooking Experiment [message #98026 is a reply to message #98006] Wed, 01 September 2010 06:50 Go to previous messageGo to next message
Ken Coit is currently offline  Ken Coit   United States
Messages: 151
Registered: November 2005
Karma: 0
Senior Member
Thanks Gene. That sounds like a relatively easy material to install. Did you
pull the tanks or is the sealant thick enough, like roofing tar, to apply
overhead?


> Ken,
>
> If you are interested in reducing radiant heat to the gas tank you might
> try what I have done. I coated the bottom and the sides of the tanks where
> I could reach with Super Silver 300 sealant. It is made for roofing but
> looks good on gas tanks. It is a sealant with what looks like black asphalt
> and aluminum particles. When you brush it on it looks black, but when it
> dries it has an aluminum finish. I have never had vapor lock but I thought
> I would try it anyway. The asphalt sealer gives a little insulation and the
> aluminum reflects heat radiation. I got the sealant at Lowes hardware in a
> gallon can. You have to stir it like crazy to get into a homogeneous
> mixture but it sure looks good on the tanks..
> --
> Gene Dotson
> 74 Canyonlands
> www.bdub.net/Motorhome_Enhancements New Windows and Aluminum Radiators
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>




--
Ken Coit, ND7N
Raleigh, NC
Parfait Royale
1978 Royale Rear Bath, 403, 3.07
_______________________________________________
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Re: [GMCnet] Fuel Cooking Experiment [message #98133 is a reply to message #98026] Wed, 01 September 2010 21:30 Go to previous messageGo to next message
shawnee is currently offline  shawnee   United States
Messages: 422
Registered: February 2004
Location: NC
Karma: 0
Senior Member
Ken Coit wrote on Wed, 01 September 2010 07:50

Thanks Gene. That sounds like a relatively easy material to install. Did you
pull the tanks or is the sealant thick enough, like roofing tar, to apply
overhead?


> Ken,
>
> If you are interested in reducing radiant heat to the gas tank you might
> try what I have done. I coated the bottom and the sides of the tanks where
> I could reach with Super Silver 300 sealant. It is made for roofing but
> looks good on gas tanks. It is a sealant with what looks like black asphalt
> and aluminum particles. When you brush it on it looks black, but when it
> dries it has an aluminum finish. I have never had vapor lock but I thought
> I would try it anyway. The asphalt sealer gives a little insulation and the
> aluminum reflects heat radiation. I got the sealant at Lowes hardware in a
> gallon can. You have to stir it like crazy to get into a homogeneous
> mixture but it sure looks good on the tanks..
> --
> Gene Dotson
> 74 Canyonlands
> www.bdub.net/Motorhome_Enhancements New Windows and Aluminum Radiators
>
--
Ken Coit, ND7N
Raleigh, NC
Parfait Royale
1978 Royale Rear Bath, 403, 3.07
_


Ken,

I put the stuff on with the tanks on the coach. It is thick and there is no problem of brushing it on. I put two coats on just for a little insulation. I was able to reach up on the sides of the tanks to coat there. I plan on dropping the tanks this winter and will do a better job on the sides then, maybe another coat on the bottom. I want to replace the lines from the tanks to the tank solenoid. I have replaced the rest of the line with fuel injection hose.


Gene Dotson
74 Canyonlands
www.bdub.net/Motorhome_Enhancements New Windows and Aluminum Radiators
Re: [GMCnet] Fuel Cooking Experiment [message #98301 is a reply to message #97919] Thu, 02 September 2010 21:41 Go to previous messageGo to next message
Larry C   United States
Messages: 1168
Registered: July 2004
Location: NE Illinois by the Illino...
Karma: 0
Senior Member
Now then, if the exhaust system is heating the fuel to within a few degrees of vaporization and you add radiant heat to the tank, you could well have a problem pulling fuel to the pump.
_____________________________________________________

Just some general thoughts here

I have talked only to a couple of people who seem to believe that the OEM coaches did not have the fuel temperature problem. Of course they had the real fuel, not the alcohol poisoned gas we have today.

To track down this problem, the first thing that has to be done is have an OEM coach as far as engine, exhaust, heat sheilds for the tanks ( on the exhaust piping ).

If anyone has the OEM configuration and has had the fuel problem, you should let us know that the OEM setup is not standing trouble free anymore due to heat.

any vehicle with headers will have to look more closely up front as they give off more heat, also see if the fuel lines have been modified and moved near a heat source.

THE OEM gas tanks were only protected by the heat shields from the exhaust pipes. Back then that was all that was needed.

Today, is the Alcohol in the fuel lowering the boiling temp so that heat from the road is enough to shut you down?

My coach is OEM as far as fuel and exhaust and I have not had the fuel problem others have visited.

I am sure the answer is out there, probably a group of guys that have done things that took care of the problem. THE FIRST QUESTION is were those coaches OEM or had they been modified.

When the exhaust pipes were changed out, were the heat shields put back on????

Did the problem start when the Headers were installed??

Coating the gas tanks may be AN ANSWER but is it THE ANSWER??




Gatsbys' CRUISER 08-18-04
74 GLACIER X, 260/455-APC-4 Bagg'r
Remflex Manifold gaskets
CampGrounds needed, Add yours to "PLACES" /> http://www.gmceast.com/travel
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Re: [GMCnet] Fuel Cooking Experiment [message #98547 is a reply to message #98301] Sat, 04 September 2010 17:18 Go to previous message
Ken Coit is currently offline  Ken Coit   United States
Messages: 151
Registered: November 2005
Karma: 0
Senior Member
Larry,

No argument on that from here. I hope that someone who experiences vapor
lock will shoot some temperatures of the tanks and lines. Have gun, but
we're not on the road.

I am encouraged by Emery's in-tank pump project, but I''ll probably try the
Carter 4070 outside before further mods to that end of the system.


--
Ken Coit, ND7N
Raleigh, NC
Parfait Royale
1978 Royale Rear Bath, 403, 3.07
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