| Re: [GMCnet] Diesel in gasoline to help stem vapor lock??? [message #94870] |
Fri, 06 August 2010 14:59  |
Gary Casey
Messages: 448
Registered: September 2009
Karma: 0
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Senior Member |
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As Emery said below, the addition of diesel fuel will reduce the octane of the
fuel. Actually, by a lot. Diesel fuel has an extremely low octane rating -
it's literally below zero. So mixing it with gasoline, even in small
quantities, will likely lead to detonation if the engine is anything close to
being knock-limited. I certainly wouldn't consider it.
Gary
>
> My dad has a 62' Chrysler Imperial that is experiencing vapor lock and other
>boiling/hot gas issues we sometimes do in our GMC's. A mechanic is his area of
>the East TX hill country (that works on antique Detroit iron) has recommended
>that he put about a quart of diesel fuel in a tank of gas to help
>alleviate/solve that issue (told to me second hand by my mom.) I think he needs
>to address other issues first, but I thought I'd ask this community if anyone
>has heard of this "solution" before and if it would work for our coaches. It
>sounds too simple to be effective; a bit like the "add a few ounces of acetone
>to your gas to increase your gas mileage." But then again who would think that
>allowing a duck or goose to stuff itself on corn or millet would ultimately give
>you something as yummy as foie gras?
>
> Regards,
> Rick
>
These things certainly do have a habit of recycling on the GMCnet.
About 2 years ago (July 2008) this subject came up.
I found my reply:
>
> I did a search on the Internet about this. I have found several suggestions
>to add a quart of diesel to a tank of gasoline (for an automobile probably about
>1 quart per 20 gallon tank).
> They claim it does reduce the vapor pressure of the mixture and therefore helps
>prevent vapor lock.
>
> However, I have also read warnings that oil (Diesel fuel is oil) mixed into the
>gasoline can harm some of the gaskets and seals in the fuel system. That makes
>sense as oils will cause rubber swell in most elastomers (synthetic rubber
>compounds commonly found in fuel pumps and carbs, etc.
>
> Another thing that I have read in a couple of places that adding diesel fuel to
>gasoline will reduce the octane number. This could lead to knock or pinging.
Emery Stora
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| Re: [GMCnet] Diesel in gasoline to help stem vapor lock??? [message #94871 is a reply to message #94870] |
Fri, 06 August 2010 15:05  |
gmcrv1
Messages: 839
Registered: August 2007
Location: Memphis
Karma: -1
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Senior Member |
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Has anyone used a product called CD-2 as an additive for engines designed to
run on leaded fuel? It is still available in stores and last week I picked
up two bottles at half price at Wal-Mart. Of course, I only use it when off
roading as it may not ne legal for on road consumption.
Tom Eckert N2VWN
73 Glacier
Oakland, TN
On Fri, Aug 6, 2010 at 2:59 PM, Gary Casey <casey.gary@yahoo.com> wrote:
> As Emery said below, the addition of diesel fuel will reduce the octane of
> the
> fuel. Actually, by a lot. Diesel fuel has an extremely low octane rating
> -
> it's literally below zero. So mixing it with gasoline, even in small
> quantities, will likely lead to detonation if the engine is anything close
> to
> being knock-limited. I certainly wouldn't consider it.
> Gary
>
> >
> > My dad has a 62' Chrysler Imperial that is experiencing vapor lock and
> other
> >boiling/hot gas issues we sometimes do in our GMC's. A mechanic is his
> area of
> >the East TX hill country (that works on antique Detroit iron) has
> recommended
> >that he put about a quart of diesel fuel in a tank of gas to help
> >alleviate/solve that issue (told to me second hand by my mom.) I think he
> needs
> >to address other issues first, but I thought I'd ask this community if
> anyone
> >has heard of this "solution" before and if it would work for our coaches.
> It
> >sounds too simple to be effective; a bit like the "add a few ounces of
> acetone
> >to your gas to increase your gas mileage." But then again who would think
> that
> >allowing a duck or goose to stuff itself on corn or millet would
> ultimately give
> >you something as yummy as foie gras?
> >
> > Regards,
> > Rick
> >
>
> These things certainly do have a habit of recycling on the GMCnet.
>
> About 2 years ago (July 2008) this subject came up.
> I found my reply:
>
> >
> > I did a search on the Internet about this. I have found several
> suggestions
> >to add a quart of diesel to a tank of gasoline (for an automobile probably
> about
> >1 quart per 20 gallon tank).
> > They claim it does reduce the vapor pressure of the mixture and therefore
> helps
> >prevent vapor lock.
> >
> > However, I have also read warnings that oil (Diesel fuel is oil) mixed
> into the
> >gasoline can harm some of the gaskets and seals in the fuel system. That
> makes
> >sense as oils will cause rubber swell in most elastomers (synthetic rubber
> >compounds commonly found in fuel pumps and carbs, etc.
> >
> > Another thing that I have read in a couple of places that adding diesel
> fuel to
> >gasoline will reduce the octane number. This could lead to knock or
> pinging.
>
> Emery Stora
>
>
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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| Re: [GMCnet] Diesel in gasoline to help stem vapor lock??? [message #94895 is a reply to message #94870] |
Fri, 06 August 2010 21:39 |
Dr. Detroit
Messages: 158
Registered: April 2010
Location: Novi, MI.
Karma: 0
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Senior Member |
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While transmission fluid may have a higher boiling point and would effectively raise the boiling point of the gasoline, just like diesel it will reduce the octane of the fuel.
I've contacted some pretty smart buddies of mine who develop fuel systems and write the fuel injection maps on special built government vehicles that must run when called on.
Their recommendation to me was to use an in tank pump and pressurize the lines to at least 43.5 psi. We did not do the calculations but a SWAG would be that the increase in pressure would raise the boil point by around 40 degrees.
They recommended that a return style regulator (to reduce pressure down to 5 psi) is placed as close to the carb inlet as possible and that the mechanical pump is deleted.
While they believed this setup would make a big difference, they did say that so far the only way to really get to a nearly failsafe setup is a 60 PSI Deadhead (returnless) Multiport Fuel Injection System like the current system on GM Trucks that can run E85 or Gas
1973 GMC 23'
All Birch and Maple Interior Cabinetry. TZE033V100221
"The Honeycomb Hideout"
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