[DeTomaso] Fuel tank ventilation - fuel spill

Mon Mar 7 11:30:51 EST 2022

Hi Mike,

I checked the interface between the vent and the top of the tank. There is
plenty of dust in that area and no signs of any fluid. I think that
interface is 100% tight. However, when shaking the vent hose, there are
fuel droplets dripping out.
Cheers
Hartwig

On Sun, Mar 6, 2022 at 10:28 PM Mike Drew <mikeldrew at aol.com> wrote:

> Hartwig,
>
> The non-linear movement of the fuel gauge is simply explained by the shape
> of the tank. It’s not a simple box. Philosophically it’s more akin to a
> pyramid.  Because it’s much smaller at the top, the fuel sender float sinks
> much more quickly at first.  So your gauge will go from full to 3/4
> relatively fast. It will move a bit more slowly from 3/4 to half, and then
> at a constant (and arguably ‘correct’) rate from half to empty.
>
> It’s probably best to return to the canister system if you can,  it it’s
> not strictly necessary.
>
> Have you determined where exactly the fuel is leaking from? I always
> assumed my tank was cracked near the top, and it would leak at least one or
> two gallons immediately if I completely filled it, which led to much
> embarrassment at the gas station. Eventually I realized that the problem
> lay with the interface between the vent and the top of the tank. The early
> aluminum tank is heavily reinforced where the filler neck and fuel level
> sender attach, but inexplicably where the vent attaches its very thin.
>
> Mine had the vent attached and reattached several times which distorted
> it.  Although I considered various means of rectifying the situation,
> because I happened to have a spare steel tank from a later car, instead I
> just replaced it.
>
> My aluminum tank has been at a Pantera buddy’s house for several years,
> awaiting us to get the energy to fabricate a reinforcing ring which would
> affix to the inside of the tank and enable the vent to be properly secured.
>
> If you pop your gas tank cover off, fill the tank to the brim and find gas
> pouring from between the top of the tank and the vent flange, that just
> might be the impetus we need to develop a fix for you, using my tank as the
> guide.
>
> The problem is detailed at length in the April 2018 PCNC newsletter,
> available to all at www.Panteraclubnorcal.com
>
> Let me know what you find out!
>
> Mike
>
> Sent from my iPad
>
> On Mar 6, 2022, at 13:13, HARTWIG ASSHAUER <hartwig.asshauer at airbus.com>
> wrote:
>
> 
> Hi Mike,
> Yes, my tank is wrapped in fibreglass. The car is from 1971 (VIN 1571).
> When I bought the car it had the canister installed but there was no vent
> hose connected to it and I removed the canister. The tank vent is connected
> to a simple rubber tube that goes straight in front of the left aft wheel.
> From the beginning I had noticed that the first quarter (fuel gauge)
> empties quite quickly. I always thought that this is due to the
> Italien non-precision instruments installed but it seems that my car is
> equipped with a fuel jettison system. Should I go back to the canister
> setup or is there a smarter way?
> Cheers
> Hartwig
>
> On Sun, Mar 6, 2022 at 5:23 PM Mike Drew <mikeldrew at aol.com> wrote:
>
>> Hartwig,
>>
>> The vent hose originally ran across the engine bay beneath the rear
>> window, into a charcoal canister.  Another hose ran from that canister to
>> the engine, although at the moment I can’t quite remember what the scheme
>> was. Was the engine also vented to the canister? Or was the canister
>> providing vacuum that drew fumes from the tank, through the canister and
>> into the engine, as modern cars do?
>>
>> In any case, if you disconnect the vent hose from the canister and
>> instead just point it at the ground, in certain rare circumstances, when
>> the tank is completely filled, it can actually siphon the engine tire
>> contents onto the ground! (I’ve only heard of that happening once).
>>
>> My car had an aluminum 1971 tank in it and used to dump fuel all the
>> time. I discovered that the top of the tank where the vent is attached was
>> very thin, and it was distorted by the attaching rivets, preventing a
>> proper seal. As the vent is below the top of the tank (which is stupid), it
>> is submerged when the tank is completely full. I know you have a 1971
>> car—is it early enough to have an aluminum tank also? (They are wrapped in
>> fiberglass, ostensibly to prevent leaks).
>>
>> Mike
>>
>> Sent from my iPad
>>
>> > On Mar 6, 2022, at 07:41, HARTWIG ASSHAUER via DeTomaso <
>> detomaso at server.detomasolist.com> wrote:
>> >
>> >    Hi fromA Toulouse (France),
>> >   I noticed for quite some time that there is often a significant fuel
>> >   smell in the garage after having driven my Pantera. After some recent
>> >   investigation I found that the underside of the car was partially wet
>> >   from fuel that was releasedA from the fuel tank venting hose. That
>> does
>> >   not look normal, right? Does the fuel tank venting have some device
>> >   installed that prevents liquid fuel leaving the tank?
>> >   Cheers
>> >   Hartwig
>> >
>> >   The information in this e-mail is confidential. The contents may not
>> be
>> >   disclosed or used by anyone other than the addressee. Access to this
>> >   e-mail by anyone else is unauthorised.
>> >   If you are not the intended recipient, please notify Airbus
>> immediately
>> >   and delete this e-mail.
>> >   Airbus cannot accept any responsibility for the accuracy or
>> >   completeness of this e-mail as it has been sent over public networks.
>> >   If you have any concerns over the content of this message or its
>> >   Accuracy or Integrity, please contact Airbus immediately.
>> >   All outgoing e-mails from Airbus are checked using regularly updated
>> >   virus scanning software but you should take whatever measures you deem
>> >   to be appropriate to ensure that this message and any attachments are
>> >   virus free.
>> > _______________________________________________
>> >
>> >
>> > Detomaso Email List is not managed by POCA
>> > Posted emails must not exceed 1.5 Megabytes
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>> >
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>> use the links above.
>> >
>> > Members who post to this list grant license to the list to forward any
>> message posted here to all past, current, or future members of the list.
>> They also grant the list owner permission to maintain an archive or approve
>> the archiving of list messages.
>>
>> The information in this e-mail is confidential. The contents may not be
> disclosed or used by anyone other than the addressee. Access to this e-mail
> by anyone else is unauthorised.
> If you are not the intended recipient, please notify Airbus immediately
> and delete this e-mail.
> Airbus cannot accept any responsibility for the accuracy or completeness
> of this e-mail as it has been sent over public networks. If you have any
> concerns over the content of this message or its Accuracy or Integrity,
> please contact Airbus immediately.
> All outgoing e-mails from Airbus are checked using regularly updated virus
> scanning software but you should take whatever measures you deem to be
> appropriate to ensure that this message and any attachments are virus free.
>
>
The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
-------------- next part --------------
   Hi Mike,
   I checked the interface between the vent and the top of the tank. There
   is plenty of dust in that area and no signs of any fluid. I think that
   interface is 100% tight. However, when shaking the vent hose, there are
   fuel droplets dripping out.
   Cheers
   Hartwig
   On Sun, Mar 6, 2022 at 10:28 PM Mike Drew <[1]mikeldrew at aol.com> wrote:

   Hartwig,
   The non-linear movement of the fuel gauge is simply explained by the
   shape of the tank. Itas not a simple box. Philosophically itas more
   akin to a pyramid.A  Because itas much smaller at the top, the fuel
   sender float sinks much more quickly at first.A  So your gauge will go
   from full to 3/4 relatively fast. It will move a bit more slowly from
   3/4 to half, and then at a constant (and arguably acorrecta) rate from
   half to empty.A
   Itas probably best to return to the canister system if you can, A it
   itas not strictly necessary.A
   Have you determined where exactly the fuel is leaking from? I always
   assumed my tank was cracked near the top, and it would leak at least
   one or two gallons immediately if I completely filled it, which led to
   much embarrassment at the gas station. Eventually I realized that the
   problem lay with the interface between the vent and the top of the
   tank. The early aluminum tank is heavily reinforced where the filler
   neck and fuel level sender attach, but inexplicably where the vent
   attaches its very thin.A
   Mine had the vent attached and reattached several times which distorted
   it.A  Although I considered various means of rectifying the situation,
   because I happened to have a spare steel tank from a later car, instead
   I just replaced it.A
   My aluminum tank has been at a Pantera buddyas house for several years,
   awaiting us to get the energy to fabricate a reinforcing ring which
   would affix to the inside of the tank and enable the vent to be
   properly secured.A
   If you pop your gas tank cover off, fill the tank to the brim and find
   gas pouring from between the top of the tank and the vent flange, that
   just might be the impetus we need to develop a fix for you, using my
   tank as the guide.A
   The problem is detailed at length in the April 2018 PCNC newsletter,
   available to all at [2]www.Panteraclubnorcal.com
   Let me know what you find out!
   Mike
   Sent from my iPad

     On Mar 6, 2022, at 13:13, HARTWIG ASSHAUER
     <[3]hartwig.asshauer at airbus.com> wrote:

   i>>?
   Hi Mike,
   Yes, my tank is wrapped in fibreglass. The car is from 1971 (VIN 1571).
   When I bought the car it had the canister installed but there was no
   vent hose connected to it and I removed theA canister. The tank vent is
   connected to a simple rubber tube that goes straight in front of the
   left aftA wheel. From the beginning I had noticed that the first
   quarter (fuel gauge) empties quite quickly. I always thought that this
   is due to the ItalienA non-precision instruments installed but it seems
   that my car is equipped with a fuel jettisonA system. Should I go back
   to the canister setup or is there a smarter way?
   Cheers
   Hartwig
   On Sun, Mar 6, 2022 at 5:23 PM Mike Drew <[4]mikeldrew at aol.com> wrote:

     Hartwig,
     The vent hose originally ran across the engine bay beneath the rear
     window, into a charcoal canister.A  Another hose ran from that
     canister to the engine, although at the moment I canat quite
     remember what the scheme was. Was the engine also vented to the
     canister? Or was the canister providing vacuum that drew fumes from
     the tank, through the canister and into the engine, as modern cars
     do?
     In any case, if you disconnect the vent hose from the canister and
     instead just point it at the ground, in certain rare circumstances,
     when the tank is completely filled, it can actually siphon the
     engine tire contents onto the ground! (Iave only heard of that
     happening once).
     My car had an aluminum 1971 tank in it and used to dump fuel all the
     time. I discovered that the top of the tank where the vent is
     attached was very thin, and it was distorted by the attaching
     rivets, preventing a proper seal. As the vent is below the top of
     the tank (which is stupid), it is submerged when the tank is
     completely full. I know you have a 1971 carais it early enough to
     have an aluminum tank also? (They are wrapped in fiberglass,
     ostensibly to prevent leaks).
     Mike
     Sent from my iPad
     > On Mar 6, 2022, at 07:41, HARTWIG ASSHAUER via DeTomaso
     <[5]detomaso at server.detomasolist.com> wrote:
     >
     > i>>?A  A Hi fromA Toulouse (France),
     >A  A I noticed for quite some time that there is often a
     significant fuel
     >A  A smell in the garage after having driven my Pantera. After some
     recent
     >A  A investigation I found that the underside of the car was
     partially wet
     >A  A from fuel that was releasedA from the fuel tank venting hose.
     That does
     >A  A not look normal, right? Does the fuel tank venting have some
     device
     >A  A installed that prevents liquid fuel leaving the tank?
     >A  A Cheers
     >A  A Hartwig
     >
     >A  A The information in this e-mail is confidential. The contents
     may not be
     >A  A disclosed or used by anyone other than the addressee. Access
     to this
     >A  A e-mail by anyone else is unauthorised.
     >A  A If you are not the intended recipient, please notify Airbus
     immediately
     >A  A and delete this e-mail.
     >A  A Airbus cannot accept any responsibility for the accuracy or
     >A  A completeness of this e-mail as it has been sent over public
     networks.
     >A  A If you have any concerns over the content of this message or
     its
     >A  A Accuracy or Integrity, please contact Airbus immediately.
     >A  A All outgoing e-mails from Airbus are checked using regularly
     updated
     >A  A virus scanning software but you should take whatever measures
     you deem
     >A  A to be appropriate to ensure that this message and any
     attachments are
     >A  A virus free.
     > _______________________________________________
     >
     >
     > Detomaso Email List is not managed by POCA
     > Posted emails must not exceed 1.5 Megabytes
     > DeTomaso mailing list
     > [6]DeTomaso at server.detomasolist.com
     > [7]http://server.detomasolist.com/mailman/listinfo/detomaso
     >
     > To manage your subscription (change email address, unsubscribe,
     etc.) use the links above.
     >
     > Members who post to this list grant license to the list to forward
     any message posted here to all past, current, or future members of
     the list. They also grant the list owner permission to maintain an
     archive or approve the archiving of list messages.

   The information in this e-mail is confidential. The contents may not be
   disclosed or used by anyone other than the addressee. Access to this
   e-mail by anyone else is unauthorised.
   If you are not the intended recipient, please notify Airbus immediately
   and delete this e-mail.
   Airbus cannot accept any responsibility for the accuracy or
   completeness of this e-mail as it has been sent over public networks.
   If you have any concerns over the content of this message or its
   Accuracy or Integrity, please contact Airbus immediately.
   All outgoing e-mails from Airbus are checked using regularly updated
   virus scanning software but you should take whatever measures you deem
   to be appropriate to ensure that this message and any attachments are
   virus free.

References

   1. mailto:mikeldrew at aol.com
   2. http://www.Panteraclubnorcal.com/
   3. mailto:hartwig.asshauer at airbus.com
   4. mailto:mikeldrew at aol.com
   5. mailto:detomaso at server.detomasolist.com
   6. mailto:DeTomaso at server.detomasolist.com
   7. http://server.detomasolist.com/mailman/listinfo/detomaso