Date: Mon, 3 Aug 2020 10:49:43 -0600
Reply-To: OlRivrRat <OlRivrRat@COMCAST.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: OlRivrRat <OlRivrRat@COMCAST.NET>
Subject: Re: Fuel hose size
In-Reply-To: <CY4PR0801MB373172E6CC4E022C7EF03FAFA04D0@CY4PR0801MB3731.namprd08.prod.outlook.com>
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The After Pump Fuel Filter (Which Usually Is & Should Be Metal), If Properly Mounted, Is an
Excellent Ground Point & that is where the approx' 6.5' of HighPress' Fuel Hose begins in the way
that I do the Upgrade ~ The "T" on the other end of that run can certainly be grounded if a need
is perceived ~ & > Static running through a material is not a problem, It Needs the Correct Gap
to another conductor to cause it to Spark ~
Any Gasoline Vapor that Might develop within the Gas Line from Tank to Injectors would be
in a Closed to Oxygen Environment & Gasoline Fumes Need Oxygen in a Relative Narrow Mixture
Ratio in order to be Ignited ~ Even if the correct Mix of Gas & Oxygen & Spark did happen within
that closed system it would most likely immediately extinguish itself by running out of Oxygen ~
Easily understandable example > A Running Fuel Injected Engine, Fuel (Gasoline, Oxygen Mix) in
Combustion Chambers Burning when Spark occurs, Oxygen Supply is Cut Off by Covering Intake
& Even Though The Gasoline Injections & Sparks Continue, the Engines Dies ~
On 2 Aug , 2020, at 10:41 PM, Dennis Haynes wrote:
> No offense taken. Properly installed the fuel tank is not grounded to the body. There should be rubber spacers on top of the flange and the lower supports have rubber bumpers to hold the tank up. The only deliberate ground is the tank level sensor. The pump is mounted on an isolated mount and the injectors are also isolated.
>
> As for vapor in the system, under certain temperature and pressure conditions it does happen. Fuel system vapor lock does happen and a system that does not maintain enough pressure can have it occur after engine shut down as that heat soak boils the fuel out of the lines above the engine. It can also happen on the inlet side of the pump, probably why VW eliminated the filter before the pump. Then there are the times where we run out of fuel and the pump starts pulling air. Usually the mixture will still be too rich to burn. I have seen fuel pumps that have obviously ignited internally. Yes that can bulge.
>
> Another consideration though is the assumption that all Vanagon fires start from fuel leaks. Even when a leak occurs you then also need an ignition source. Over the years I have recovered and repaired a number of vans that had minor engine compartment fires. I think many actually start out as electrical failures. One thing about VW wiring, there are so many circuits that do not have any over current or short circuit protection. And for the equipment that does many like the lights have the fuses after the switches. So much wiring before. I have seen both starters and alternators burn up. Also the battery positive cable where a clamp supports it near the starter. Or the harness from the battery to the fuse box. I have 97 Eurovan here now that had the engine harness go up. Everything from the battery to /from the fuse box and the engine wiring all damaged. And no Comprehensive insurance?
>
> Dennis
>
>
> -----Original Message-----
> From: OlRivrRat <OlRivrRat@comcast.net>
> Sent: Sunday, August 2, 2020 12:30 PM
> To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
> Cc: vanagon@GERRY.VANAGON.COM
> Subject: Re: Fuel hose size
>
> Dennis
>
> While I generally consider You to be the Guru among Us when it comes to most
>
> things Vanagon Related, I'm going to respectfully disagree on this one ~ Yes Static can
>
> be generated by a fluid flowing through a tube but in the case We are talking about
>
> here @ both ends of the tube the fluid comes in contact with Grounded Metal & @ No
>
> Point Between the Gas Tank & the Fuel Injector Nozzles is that Gas allowed to Vaporize
>
> Nor is there a Gap in that Path that could give rise to Static Spark ~
>
> The Reason for the Warning Signage @ Gas Pumps is an attempt to Prevent a
>
> Static Spark from Occurring between the Pump Nozzle & Whatever Container is being
>
> filled, in an Environment Rich with Gas Fumes, which are being created by the Filling
>
> of the Container, are Mixing with Air & thereby creating a Highly Ignitable Fuel ~
>
> As to VW Engineers Smarts > Clamping a Rubber Hose around a Thin Plastic
>
> Tube for the purpose of transporting Gasoline > Not Smart IMHO > & Then,, Placing
>
> that Connection Directly Above a Starter Motor ....... Boom ~
>
> & that Plastic FireWall PassThru I Suspect just happened to be able to be produced
>
> by a BrotherInLaw of 1 of those VW Engineers & to offset the expense of that part the
>
> Plastic Tube was put in to replace Expensive Fuel Injection Hose ~
>
> ORR ~ DeanB
>
>
> On 2 Aug , 2020, at 8:53 AM, Dennis Haynes wrote:
>
>> I am not sure that this is a good approach. When looking at fuel hoses we look at pressure and temperature ratings and we pay attention to the outer jacket and how it will interface with clamps. What I never see mentioned is conductivity or the ability to dissipate static charges nor the ability to resist electrolysis. That is what really causes hoses to crack and fail on the inside.
>>
>> Whenever a fluid flows through a tube or hose static charges are generated. Even when you fill a plastic gas can, the can is static dissipative and hence the signs at the filling station advising the container shall be placed on the ground and the nozzle in contact with the container while filling. That plastic tube is a life time part. Hoses are not although the original have lasted 10 -15 years or even more. With VW being cost conscious as they are there is no part or design that doesn't serve some purpose. My thoughts are that the hose sections are kept short for a reason and it could even be that that firewall nipple is a strategically place insulator, in addition to a service feature for engine removal. The longer a hose the higher the static potential can be. I really don't know, just a thought and all modifications needs thought. I just give the VW engineers credit for knowing a lot more than me.
>>
>> Dennis
>>
>>
>> -----Original Message-----
>> From: Vanagon Mailing List <vanagon@gerry.vanagon.com> On Behalf Of
>> Richard Koerner
>> Sent: Saturday, August 1, 2020 7:37 PM
>> To: vanagon@GERRY.VANAGON.COM
>> Subject: Re: Fuel hose size
>>
>> Superb! Well thought out.
>>
>> On Saturday, August 1, 2020, 3:46:04 PM PDT, OlRivrRat <olrivrrat@comcast.net> wrote:
>>
>> IMHO,, The Correct Way To Do the Fuel Supply Hose Replacement
>>
>> & The Way that I Always Recommend that It Be Done is to Run 1 Single
>>
>> Length of High Pressure Fuel Injection Hose frm Fuel Filter to the
>> Splitter
>>
>> "T" by the OilBreather Tower ~ You end up with Only 2 Possible Leak
>> Points
>>
>> Instead of 6 & a Brand New, Really Strong, All 1 ID Hose ~
>>
>> (I use 225PSI Gates 5/16) It is Pricey Hose @ about $3.50/Ft but only
>> takes
>>
>> about 6.5Ft >> Way Cheaper than an Engine Fire ~
>>
>> Also >> I usually DoNot run the Hose back through the hole
>> left by the
>>
>> removal of the Old Plastic PasThru Fitting, I just run it under the
>> FireWall &
>>
>> then it aligns nicely with passing under the Intake ~
>>
>> ORR ~ DeanB
>>
>>
>> On 31 Jul , 2020, at 7:03 PM, Rob wrote:
>>
>>> 7.5mm, thank you. The last time I did this the plastic tube was a
>>> good fit inside the hose, I ran it in 6" or so & used two clamps with
>>> no leaks. I was planning on doing this again.
>>>
>>> Rob
>>> vwrobb@gmail.com
>>>
>>>
>>> On Fri, Jul 31, 2020 at 3:30 PM Dennis Haynes
>>> <d23haynes57@hotmail.com>
>>> wrote:
>>>
>>>> At some point VW went to a 7.5mm ID hose in part to reduce reliance
>>>> on the clamps. For the firewall fitting it gets a bad rap. A more
>>>> common place to leak is where the hose attaches to the plastic tube
>>>> from the filter. Hose selection and clamp choice and installation is
>>>> extremely critical. Too lose and the hose slides off or leaks, too
>>>> tight and the plastic tube collapses especially after some heat. On
>>>> other vehicles that use this type of tube a sleeve goes inside to support the tube from collapsing.
>>>>
>>>> Spring or crimp clamps are the best choice here.
>>>>
>>>> It is worth noting the OEM the hoses on the engine and outside the
>>>> compartment are different part numbers-construction. With the
>>>> aftermarket stuff we go from 10-15 year hoses to 2-5!
>>>>
>>>> Dennis
>>>>
>>>>
>>>> -----Original Message-----
>>>> From: Vanagon Mailing List <vanagon@gerry.vanagon.com> On Behalf Of
>>>> Rob
>>>> Sent: Friday, July 31, 2020 4:59 PM
>>>> To: vanagon@GERRY.VANAGON.COM
>>>> Subject: Fuel hose size
>>>>
>>>> What size fuel hose do I need to replace the one from the firewall
>>>> plastic fitting to the engine?
>>>>
>>>> Rob
>>>> vwrobb@gmail.com
>>>>
>
