Re: Fuel tank made from Stainless steel? (long!)

["Walter Coe" <Whalt@xxxx>]

Comments on Robert's post:

> 1. The high pressue line on the fuel pump is touching the
> fiberglass underbody, and thus transmits the vibrations that
> resonate throughout the car.

I hear you, and I hear it; but this isn't the problem I'm trying to solve.
My fuel pump is noisy like most everyone else's all the time, but I'm trying
to cure a specific temperature/noise correlated problem. When the fuel gets
hot, the pump becomes extremely noisy -- making all kinds of rude
farting/gurgling noises.

> 2. Gasoline gets hot, softens the pickup hose on the pump, and
> negative pressure inside the hose causes it to collapse. Thus
> the fuel pump is starved of liquid to lubricate it, and it begins to
> whine.

I hear you again, and again I eliminated this as a possible problem by 1)
replacing my OEM fuel suction hose with the PJ Grady variety which is
noticeably thicker, stiffer & heavier, but I still get the temperature
related noisy fuel pump problem. 2) So next I stretched out a screen door
spring and threaded it through the new hose. This didn't help at all.
While the fuel is cool, the pump is pretty much silent; however, with
extended abuse its base line noise has increased substantially. I think it
is on it's way out, so I'm driving around now with a spare fuel pump & tools
to change it out just in case. On a hot day after a trip across town, I put
a thermometer in my tank and measured the temperature to be 118 degrees
Fahrenheit.

> Deflectors
> for the front radiator are a waste of time, materials, and vehicle
> weight. The prevent high flow exhaust from the front radiator, and
> they can cause a pressure lock-up at speeds over 70MPH as I
> have been told.

I have looked into installing a deflector and can easily see the problems
you mention. My suggestion is to construct a deflector that is shaped like
a plow that would fit between the fiberglass underbody and the frame. This
wouldn't restrict air movement as much as other designs. Since one of my
radiator fans might be going bad (I can't tell if it is howling occasionally
or if it is my fuel pump that is going bad) I might consider building a new
radiator shroud to hold aftermarket radiator fans. It would have a shape
that would duct the air away from the fuel tank. I'm thinking that putting
the new fans in front of the radiator might work better.

Comments on Sean's post:

> Instead of producing a stainless tank to make room for insulation, etc. as
> well as reducing the volume of the tank, have you considered installing a
> fuel radiator on the return line? Summit Racing has a dual pass radiator
> meant for this purpose.

I have spotted this in their catalogue before and am seriously considering
it. I'm thinking that maybe the best place for it would be in the frame
near the fuel accumulator and be installed in the fuel return line. The one
that Summit Racing has seems too small according to their photo. Maybe an
oil cooling radiator could be made to work better. If done properly, I
don't see how it could be any more or less dangerous than one made for fuel.

Comments to Martin's post:

> The stock tank is a superb material and was designed that way for
crash-worthiness.

I agree that it is a superb material since I bought a running gear that had
been baking out in the sun for 3 or 4 years. The exposed OEM tank shows
almost no signs of sun damage. Though, I don't think this would make the
tank any more crash-worthy. I have seen a photo of a RHD conversion that
used a metal tank. I'd like to know more about that as well as the one that
Don @ DeLorean Motor Company came up with.

Comments to Farrar's post:

> A stainless fuel tank sounds wonderful. Have you considered aluminum?

I think that aluminum would be a bad idea because it corrodes more. For the
fuel pump, this isn't much of a problem, but the tank would be susceptible
to water collecting at the bottom and also to condensation clinging to the
top. In order to be practical, an aluminum tank would need to be coated.
There are paints specifically made for this, but I would rather not have to
fool with it.

As for one material having better insulating properties than another, this
is a weird situation with the fuel tank. Making a tank out of materials
that conduct heat better than the OEM plastic will probably make it more apt
to pick up heat from the coolant pipes and hot air from the radiator.

My main concern at this point is not making the fuel pump more quiet in as
much as keeping the fuel cooler for other reasons. 118F is just too hot for
fuel. It taxes the evaporative control system. It allows the more volatile
components to boil off sooner. It allows the oxygenated components to
degrade quicker. If I were going to put my car in storage and wanted to do
it with a minimum amount of fuel left in the tank, I wouldn't want to do it
with fuel that had been previously cooked in there. (Not that I would store
a car with fuel in it anyway.)

My long term goal is to change out the frame with a stainless one. But
first Pearce Design has to finish making it. I was supposed to have it two
months ago, but then I tell them I'm not in any hurry. So I suppose now
they aren't either. When I move everything over to the new frame, I'm going
to experiment with installing an air deflector, fuel radiator, and possibly
a stainless fuel tank. I was just looking over my junk frame today that
still has the fuel tank inside. It wouldn't take a lot of volume from the
tank to make room for 1/2" or so of foam refrigerant pipe insulation. Any
volume that is consumed in this way could be made up for by making the tank
longer in the front. The rubber pads there don't need to be that thick.
There clearances on the sides maybe could be less, too. (But when I removed
my tank before, I remember having to stand in the trunk and stomp it out.)
When done, a new tank with room for insulation could have a larger capacity
than the OEM. Food for thought.

Walt Tampa, FL