Re: Repeatedly Running On A Low Tank?
 

Retired VIP wrote:
> On Thu, 05 Jun 2008 06:34:36 +1000, John Henderson
> <jhenRemoveThis@talk21.com> wrote:
>
>> hachiroku wrote:
>>
>>> You're right. You wait until it's full of metal particles and
>>> starts to gel...
>> jim's right. Real-world data relating wear to oil change
>> frequency agree that wear is greatest for some time just after
>> an oil change.
>>
>> "Testing with partially stressed oil, which contained some wear
>> debris, produced less wear than testing with clean oil. This
>> finding was unexpected and initially confusing (further inquiry
>> suggested that the result was not so surprising, as many oil
>> chemistries require time and temperature to enhance their
>> effectiveness)."
>> http://www.swri.org/3pubs/IRD1999/03912699.htm
>>
>> "Contrary to common perception, changing oil more often than
>> recommended has been shown to increase engine wear. An ongoing
>> University of Michigan study has shown that the greatest wear
>> occurs in the first 3000km of an oil's life in any engine!"
>> http://tinyurl.com/32653c
>>
>> John
>
> Those two links are very interesting. Who would have thought that
> dirty, old oil was better at lubricating an engine than clean fresh
> oil? How much sand would you recommend I add to the crankcase when I
> change my oil to eliminate that dreaded first 3000 km of wear?

a couple of grams. diamond is better than silica though. seriously,
one of my old profs had done some research on using 0.25 micron diamond
polishing dust in new engines. apparently it reduced wear and decreased
friction substantially. wish i had the data.


> I
> wonder if just not replacing the oil filter would help reduce engine
> wear?
>
> How did I get engines to last over 100,000 miles changing the oil and
> filter every 3,000 to 3,500 miles?

you didn't - they lasted that long in spite of your treatment, not
because of it.


>
> In case you haven't guessed, I think the above is BS. Looks like an
> April fool article to me.

swri is bogus???

Re: Repeatedly Running On A Low Tank?
 

Ray O wrote:
> "jim beam" <spamvortex@bad.example.net> wrote in message
> news:MdqdndoTpso0xNrVnZ2dnUVZ_h_inZ2d@speakeasy.ne t...
>> Bill Putney wrote:
> <snipped>
>>> The bathing of the pump in fuel certainly doesn't do it any harm. But I
>>> strongly suspect that the overwhelmingly primary motivation on moving the
>>> pump to the tank was consolidating more parts into fewer assemblies to be
>>> installed into the vehicle.
>> no, its vapor lock avoidance. if the pump is at the top of a long suction
>> column, the liquid in the column can separate and once there's vapor,
>> pumping is seriously impaired. you could draw from the bottom of the
>> tank, but then you get guaranteed particle blockage and much greater
>> chance of damage.
>>
>
> Vapor lock was not a problem when electric fuel pumps for fuel injected
> engines were not integrated in the fuel tank, so it doesn't make sense to
> make a change for a problem that didn't exist. Vapor lock could occur in
> the old mechanical fuel pumps that produced less than 10 PSI. Electric
> fuel pumps for fuel injected engines run over 40 PSI so vapor lock is not a
> problem.

i'm talking about the sucking side, not the pushing side. if you suck
hard enough on any liquid, the column separates. if it's a liquid full
of volatiles, especially on a hot day at high altitude, you'll not have
to suck very hard. hence you attempt to keep the column rise as close
to zero as possible. putting the pump down in the tank achieves exactly
that.


>
> Bill Putney's explanation is much more feasible.

its definitely part of the picture, but it's not the full story - you
could easily mount such an assembly on the engine.

Re: Repeatedly Running On A Low Tank?
 

On Wed, 04 Jun 2008 20:12:49 -0700, jim beam wrote:

> Hachiroku ãƒ�ãƒ�ãƒã‚¯ wrote:
>> On Wed, 04 Jun 2008 06:15:31 -0700, jim beam wrote:
>>
>>>> Three separate 'ideas'. Wanted to make sure you didn't get too
>>>> confused. It seems to happen to you quite often.
>>> so you make three separate trips to the supermarket in one day? that's
>>> not too smart.
>>>
>>> btw, don't accuse me of /your/ confusion problem. see above. thanks.
>>
>>
>> I don't have a problem.
>
> but you do - you just posted three different replies the same comment -
> that's definitive evidence of a problem with your cognitive function.

Not at all. I didn't want your head to explode by jamming three concepts
into it at once.

And here I am trying to be considerate...

Re: Repeatedly Running On A Low Tank?
 

Hachiroku ãƒ�ãƒ�ãƒã‚¯ wrote:
> On Wed, 04 Jun 2008 20:12:49 -0700, jim beam wrote:
>
>> Hachiroku ãƒ�ãƒ�ãƒã‚¯ wrote:
>>> On Wed, 04 Jun 2008 06:15:31 -0700, jim beam wrote:
>>>
>>>>> Three separate 'ideas'. Wanted to make sure you didn't get too
>>>>> confused. It seems to happen to you quite often.
>>>> so you make three separate trips to the supermarket in one day? that's
>>>> not too smart.
>>>>
>>>> btw, don't accuse me of /your/ confusion problem. see above. thanks.
>>>
>>> I don't have a problem.
>> but you do - you just posted three different replies the same comment -
>> that's definitive evidence of a problem with your cognitive function.
>
> Not at all. I didn't want your head to explode by jamming three concepts
> into it at once.
>
> And here I am trying to be considerate...
>
>


pfft.

Re: Repeatedly Running On A Low Tank?
 

On Wed, 04 Jun 2008 21:40:58 -0700, jim beam wrote:

> Hachiroku ãƒ�ãƒ�ãƒã‚¯ wrote:
>> On Wed, 04 Jun 2008 20:12:49 -0700, jim beam wrote:
>>
>>> Hachiroku ãƒ�ãƒ�ãƒã‚¯ wrote:
>>>> On Wed, 04 Jun 2008 06:15:31 -0700, jim beam wrote:
>>>>
>>>>>> Three separate 'ideas'. Wanted to make sure you didn't get too
>>>>>> confused. It seems to happen to you quite often.
>>>>> so you make three separate trips to the supermarket in one day?
>>>>> that's not too smart.
>>>>>
>>>>> btw, don't accuse me of /your/ confusion problem. see above.
>>>>> thanks.
>>>>
>>>> I don't have a problem.
>>> but you do - you just posted three different replies the same comment -
>>> that's definitive evidence of a problem with your cognitive function.
>>
>> Not at all. I didn't want your head to explode by jamming three concepts
>> into it at once.
>>
>> And here I am trying to be considerate...
>>
>>
>>
>
> pfft.


Bet you like hitting yourself in the head with a ball-peen hammer, too...

Re: Repeatedly Running On A Low Tank?
 

"jim beam" <spamvortex@bad.example.net> wrote in message
news:RPCdnYTxjp98-trVnZ2dnUVZ_jidnZ2d@speakeasy.net...
> Ray O wrote:
>> "jim beam" <spamvortex@bad.example.net> wrote in message
>> news:MdqdndoTpso0xNrVnZ2dnUVZ_h_inZ2d@speakeasy.ne t...
>>> Bill Putney wrote:
>> <snipped>
>>>> The bathing of the pump in fuel certainly doesn't do it any harm. But
>>>> I strongly suspect that the overwhelmingly primary motivation on moving
>>>> the pump to the tank was consolidating more parts into fewer assemblies
>>>> to be installed into the vehicle.
>>> no, its vapor lock avoidance. if the pump is at the top of a long
>>> suction column, the liquid in the column can separate and once there's
>>> vapor, pumping is seriously impaired. you could draw from the bottom of
>>> the tank, but then you get guaranteed particle blockage and much greater
>>> chance of damage.
>>>
>>
>> Vapor lock was not a problem when electric fuel pumps for fuel injected
>> engines were not integrated in the fuel tank, so it doesn't make sense to
>> make a change for a problem that didn't exist. Vapor lock could occur in
>> the old mechanical fuel pumps that produced less than 10 PSI. Electric
>> fuel pumps for fuel injected engines run over 40 PSI so vapor lock is not
>> a problem.
>
> i'm talking about the sucking side, not the pushing side. if you suck
> hard enough on any liquid, the column separates. if it's a liquid full of
> volatiles, especially on a hot day at high altitude, you'll not have to
> suck very hard. hence you attempt to keep the column rise as close to
> zero as possible. putting the pump down in the tank achieves exactly
> that.

I have no experience with fluid dynamics so I'll have to take your word
about the phenomenon. I would imagine that while 40+ PSI is enough to
prevent vapor lock on the pushing side, it isn't enough to cause the column
separation that you are describing since I've never heard of that happening
either. Wouldn't increasing the diameter of the suction side reduce the
pressure and therefore the tendency of the column to separte? If so, it
seems like that would be a simpler solution than re-designing the fuel pump,
tank, and mounting hardware.

In other words, it seems to me that lowering assembly costs would be the
primary reason for mounting the fuel pump in the tank, and reducing the
phenomenon you are describing would be a secondary side benefit.
--

Ray O
(correct punctuation to reply)

Re: Repeatedly Running On A Low Tank?
 

Tony Hwang wrote:
> Bill Putney wrote:
>> Tony Hwang wrote:
>>
>>> ToMh wrote:
>>>
>>>> On Jun 2, 4:51 pm, Bill Putney <b...@kinez.net> wrote:
>>>>
>>>>> ToMh wrote:
>>>>>
>>>>>> On Jun 2, 2:12 am, "Don't Taze Me, Bro!" <N00One...@NoWhere.Com>
>>>>>> wrote:
>>>>>>
>>>>>>> Consider filling up your tank and not letting it drop below
>>>>>>> halfway, instead
>>>>>>> of keeping it on low and only putting in 2 gallons here and there...
>>>>>
>>>>>
>>>>>>> http://www.foxnews.com/story/0,2933,361347,00.html
>>>>>
>>>>>
>>>>>>> Not because you could run out of gas and get stranded but because
>>>>>>> repeatedly
>>>>>>> running on low tends to ruin the fuel pump.
>>>>>
>>>>>
>>>>>> The fuel pump is like any other fluid pump. it requires the liquid
>>>>>> running through it to lubricate and cool it. If you run a pump dry,
>>>>>> its seals can burn out fast.
>>>>>
>>>>>
>>>>> No. There are no dynamic seals in fuel pumps like in a typical
>>>>> automotive water pump. Running dry (not a credible situation in
>>>>> general) would not affect case seals (which are static crimped seals).
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>>> But as long as there is fluid running
>>>>>> through it, it will be fine. So as long as there is gas running
>>>>>> through the pump, it won't get damaged, but I could certainly see how
>>>>>> it could be damaged if you let it run out of gas...
>>>>>
>>>>>
>>>>> Not likely since the pumping section is at the bottom of the pump, so
>>>>> when you "run out of gas", there is a column of fuel extending from
>>>>> the
>>>>> pumping section of the pump (at its very bottom), thru the pump,
>>>>> all the
>>>>> way to the fuel rail and injectors. Granted that column of fuel is
>>>>> not
>>>>> moving, but it's there nonetheless. And the engine dies, and the
>>>>> computer turns the pump off in a matter of seconds. No real chance
>>>>> for
>>>>> significant damage from heat or lack of lubrication.
>>>>>
>>>>>
>>>>>> Just having a low
>>>>>> tank, without the pump running dry, can't possibly cause any
>>>>>> problems.
>>>>>
>>>>>
>>>>> I'll buy that.
>>>>>
>>>>>
>>>>
>>>> Thanks for the info. It sounds like you'd have to practically let all
>>>> the gas evaporate before it causes a problem.
>>>>
>>> Hi,
>>> In cold weather too low fuel in the tank causes condensation which
>>> leads to water. There is high possibility at the bottom of tank is
>>> some water.
>>> I never go lower than 1/4 full on gauge at any time year round. If
>>> liquid sloshes around, there is a possibility the pump can run dry
>>> momentarily or water can be sucked in. Also there could be some rust
>>> particles/debris which could cause clog. Just my two bits.
>>
>>
>> Sloshing around is no problem. Copying my comments from a previous
>> post 9that you inluded above):
>> >>> Not likely since the pumping section is at the bottom of the
>> pump, so
>> >>> when you "run out of gas", there is a column of fuel extending
>> from the
>> >>> pumping section of the pump (at its very bottom), thru the pump,
>> all the
>> >>> way to the fuel rail and injectors...
>>
>> As far as condensation - it is not the problem it used to be. It used
>> to be that the tank was "open" to the air, and was able to "breathe"
>> as the ambient temperatures warmed and cooled (and air moved in and
>> out of the tank) with time of day. This brought in a continuous fresh
>> supply of moisture-laden air to condense out in the tank. With sealed
>> tanks, you do get moisture coming in, but only as the tank emptied as
>> the level dropped. That amount of moisture is a fraction of what
>> would come in in a "breathing" system. The small amount generally
>> does not overload the fuel and is able to be handled without
>> noticeable symptoms. In some colder climates, it might be advisable to
>> put in a can of Dri-Gas periodically. Also - don't forget plastic
>> tanks (that don't rust.
>>
>> However - it's certainly fine with you keeping your level above 1/4 -
>> no harm, and arguably some extra margin against problems.
>>
>> Bill Putney
>> (To reply by e-mail, replace the last letter of the alphabet in my
>> address with the letter 'x')
> Hmmm,
> I don't think you have an experience living in an extreme cold climate.
> Ever used a gas line anti freeze? Ever experienced frozen up carburetor
> in old days?
> You have to open the cap to fill, some times it rains/snows, etc. Tank
> is metal, when cold it always causes cendensation. Does your car have
> insulated tank? I am talking about at least -30 degree temperature.
> I guarantee any fuel tank has some water at the bottom. Sloshing around
> means driving in rough terrain, winding mountain roads, up and down
> hill, etc. Just running low on fuel too often is generally bad thing to
> do. What if you got stuck in a traffic jam? You may run out of gas, right?

You must have not read where I wrote in what you quoted "...The small
amount generally does not overload the fuel and is able to be handled
without noticeable symptoms. In some colder climates, it might be
advisable to put in a can of Dri-Gas periodically. Also - don't forget
plastic tanks (that don't rust..."

Tanks today are plastic, right? I agree that in the past it would have
been a much bigger problem.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

Re: Repeatedly Running On A Low Tank?
 

jim beam wrote:
> Bill Putney wrote:
>> Hachiroku ãƒ�ãƒ�ãƒã‚¯ wrote:
>>> On Wed, 04 Jun 2008 06:40:33 -0700, jim beam wrote:
>>>
>>>>> I have no problem with you saying that - but be clear that you are not
>>>>> attributing that to me. Not saying you were, but someone might read it
>>>>> as such.
>>>> no, not you. but the general bleating here before you came along
>>>> was the
>>>> usual misguided crap about immersion, with people citing failures for
>>>> specific vehicles and trying to extrapolate to the whole population.
>>>
>>>
>>> There must be some reason for going from in-line to in the tank.
>>> My guess is to keep the pump bathed in gasoline.
>>> So I do.
>>
>> It's to save money for the manufacturer. Anytime they can have a
>> supplier consolidate multiple parts/sub-assemblies into a single
>> larger assembly, it is cheaper for vehicle manufacturer, which is
>> actually just an assembler of the components and assemblies that the
>> suppliers actually manufacture and ship to them. Think of the steps
>> in assembling an in-line pump *plus* the sender unit *plus* the
>> regulator *plus* the filter vs. assembling the one
>> sender/pump/regulator/filter assembly into the tank. Plus the vehicle
>> manufacturer has greatly cut their costs of negotiating and
>> administering contracts by having one line item to deal with vs. many
>> line items of the multiple components/subassemblies.
>>
>> Keep in mind that the overhead and labor costs of the suppliers are
>> much less than the cost of the vehicle manufacturers (for several
>> reasons: union/non-union, regional labor rates, Mexico labor rates,
>> etc.). So there is a net gain with having the supplier deal with the
>> multiple parts than the vehicle manufacturer receiving them in,
>> inventorying, unpacking, shuttling around, and installing in their
>> plant. I know this for a fact first hand.
>>
>> The bathing of the pump in fuel certainly doesn't do it any harm. But
>> I strongly suspect that the overwhelmingly primary motivation on
>> moving the pump to the tank was consolidating more parts into fewer
>> assemblies to be installed into the vehicle.
>
> no, its vapor lock avoidance. if the pump is at the top of a long
> suction column, the liquid in the column can separate and once there's
> vapor, pumping is seriously impaired. you could draw from the bottom of
> the tank, but then you get guaranteed particle blockage and much greater
> chance of damage.

Most in-lines I've seen were near the fuel tank (to - as you say - avoid
vapor lock). The integration of the pump into the sending unit had
different motivations than what were already met with in-line pumps.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

Re: Repeatedly Running On A Low Tank?
 

jim beam wrote:
> Ray O wrote:
>> "jim beam" <spamvortex@bad.example.net> wrote in message
>> news:MdqdndoTpso0xNrVnZ2dnUVZ_h_inZ2d@speakeasy.ne t...
>>> Bill Putney wrote:
>> <snipped>
>>>> The bathing of the pump in fuel certainly doesn't do it any harm.
>>>> But I strongly suspect that the overwhelmingly primary motivation on
>>>> moving the pump to the tank was consolidating more parts into fewer
>>>> assemblies to be installed into the vehicle.
>>> no, its vapor lock avoidance. if the pump is at the top of a long
>>> suction column, the liquid in the column can separate and once
>>> there's vapor, pumping is seriously impaired. you could draw from
>>> the bottom of the tank, but then you get guaranteed particle blockage
>>> and much greater chance of damage.
>>>
>>
>> Vapor lock was not a problem when electric fuel pumps for fuel
>> injected engines were not integrated in the fuel tank, so it doesn't
>> make sense to make a change for a problem that didn't exist. Vapor
>> lock could occur in the old mechanical fuel pumps that produced less
>> than 10 PSI. Electric fuel pumps for fuel injected engines run over
>> 40 PSI so vapor lock is not a problem.
>
> i'm talking about the sucking side, not the pushing side. if you suck
> hard enough on any liquid, the column separates. if it's a liquid full
> of volatiles, especially on a hot day at high altitude, you'll not have
> to suck very hard. hence you attempt to keep the column rise as close
> to zero as possible. putting the pump down in the tank achieves exactly
> that.
>
>
>>
>> Bill Putney's explanation is much more feasible.
>
> its definitely part of the picture, but it's not the full story - you
> could easily mount such an assembly on the engine.

Heat is the enemy, and the primary cause of vapor lock - but - yes - the
negative pressure also would contribute to vapor lock.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

Re: Repeatedly Running On A Low Tank?
 

Hachiroku ãƒ�ãƒ�ãƒã‚¯ wrote:
> On Wed, 04 Jun 2008 21:40:58 -0700, jim beam wrote:
>
>> Hachiroku ãƒ�ãƒ�ãƒã‚¯ wrote:
>>> On Wed, 04 Jun 2008 20:12:49 -0700, jim beam wrote:
>>>
>>>> Hachiroku ãƒ�ãƒ�ãƒã‚¯ wrote:
>>>>> On Wed, 04 Jun 2008 06:15:31 -0700, jim beam wrote:
>>>>>
>>>>>>> Three separate 'ideas'. Wanted to make sure you didn't get too
>>>>>>> confused. It seems to happen to you quite often.
>>>>>> so you make three separate trips to the supermarket in one day?
>>>>>> that's not too smart.
>>>>>>
>>>>>> btw, don't accuse me of /your/ confusion problem. see above.
>>>>>> thanks.
>>>>> I don't have a problem.
>>>> but you do - you just posted three different replies the same comment -
>>>> that's definitive evidence of a problem with your cognitive function.
>>> Not at all. I didn't want your head to explode by jamming three concepts
>>> into it at once.
>>>
>>> And here I am trying to be considerate...
>>>
>>>
>>>
>> pfft.
>
>
> Bet you like hitting yourself in the head with a ball-peen hammer, too...
>
>

please try to think rationally for a moment - you're again projecting a
problem /you/ have, onto a third party. in this case, a third party
you've never met. is that the way you want to keep on living your life?
at this juncture, professional help is probably your best option.

Re: Repeatedly Running On A Low Tank?
 

On Tue, 03 Jun 2008 18:21:52 -0400, Bill Putney wrote:

>>> Telltale signs of an urban legend maybe?
>>
>> and without it, there would be 90% less usenet traffic.
>
> Well - that, global warming, and K&N air filters.

I dunno about the K&N filters...

I had a '95 Tercel, and got a cold air intake for it for $50. Now, I
didn't put a K&N on it, but it was a similar filter, and my gas mileage
went from ~40 to ~45 MPG. And I did notice a better throttle response off
the line, too.

Re: Repeatedly Running On A Low Tank?
 

On Thu, 05 Jun 2008 05:26:48 -0700, jim beam wrote:

>> Bet you like hitting yourself in the head with a ball-peen hammer,
>> too...
>>
>>
>>
> please try to think rationally for a moment - you're again projecting a
> problem /you/ have, onto a third party.

Not at all. After all, you keep responding, don't you?

Re: Repeatedly Running On A Low Tank?
 

hachiroku wrote:
> On Thu, 05 Jun 2008 05:26:48 -0700, jim beam wrote:
>
>>> Bet you like hitting yourself in the head with a ball-peen hammer,
>>> too...
>>>
>>>
>>>
>> please try to think rationally for a moment - you're again projecting a
>> problem /you/ have, onto a third party.
>
> Not at all. After all, you keep responding, don't you?
>


you'll never have a chance of fixing a problem if you don't realize you
have one. you have a problem. go fix it.

Re: Repeatedly Running On A Low Tank?
 

On Tue, 03 Jun 2008 19:24:28 -0700, jim beam wrote:


>> While it might be mounted throught the top of the tank, I believe in
>> most cases the pump is actully near the bottom of the tank. I looked at
>> my shop manual for the Camry and it appears that the fuel pump stack is
>> set up so that the pump is mounted directly on top of the pick-up sock.
>> This implies it is almost always surrounded by some fuel unless level
>> in the tank is very low. Here is a picture of a Camry Fuel Pump
>> assembly -
>> http://info.rockauto.com/getimage/getimage.php?
imagekey=977329&imageurl=http%
>>
>> Ed
>>
>>
>>
> why is everyone so hung up on immersion? gasoline isn't exactly the
> greatest cooling liquid because it has a low specific heat capacity.
> what's important is circulation /within/ the pump, not /without/.

So on one hand, you're saying gasoline flowing through the pump is enough
to cool it, and then you say gas isn't efficient enough at cooling?

Stop and think...maybe that's why they put them in the tank.

Put the ball peen hammer away.

Re: Repeatedly Running On A Low Tank?
 

hachiroku wrote:
> On Tue, 03 Jun 2008 19:24:28 -0700, jim beam wrote:
>
>
>>> While it might be mounted throught the top of the tank, I believe in
>>> most cases the pump is actully near the bottom of the tank. I looked at
>>> my shop manual for the Camry and it appears that the fuel pump stack is
>>> set up so that the pump is mounted directly on top of the pick-up sock.
>>> This implies it is almost always surrounded by some fuel unless level
>>> in the tank is very low. Here is a picture of a Camry Fuel Pump
>>> assembly -
>>> http://info.rockauto.com/getimage/getimage.php?
> imagekey=977329&imageurl=http%
>>> Ed
>>>
>>>
>>>
>> why is everyone so hung up on immersion? gasoline isn't exactly the
>> greatest cooling liquid because it has a low specific heat capacity.
>> what's important is circulation /within/ the pump, not /without/.
>
> So on one hand, you're saying gasoline flowing through the pump is enough
> to cool it, and then you say gas isn't efficient enough at cooling?
>
> Stop and think...maybe that's why they put them in the tank.
>
> Put the ball peen hammer away.
>

lack of comprehension. projection of own inadequacy. get help.