For Walt

["checksix3" <checksix3@xxxx>]

>>> don't see much of a point in a custom baffle since the OEM isn't 
too bad in my opinion (unless you don't like the thought of paying 
$92 for a rubber hose that may need to be replaced in another 20 
years).<<<

I try to avoid elastomers submerged in fuel unless needed for sealing 
or gasketing purposes. Stainless will last 100 years as its not 
effected by heat or storage and will not collapse. One less thing to 
worry about.

>>>Eliminating the long flexible suction hose means proper height of 
the fuel suction screen is going to be touchy -- too low and it will 
conduct vibration; too high and it will suck air when the tank is 
low. I would try to design it so that the baffle fills faster than 
it empties, but still have the suction low enough so that it won't 
suck air when you first start the car from an almost empty tank, 
i.e., the level in the baffle will be as low as the rest of the 
tank.<<

I don't feel vibration is a problem but if it is, there are several 
solutions. Of course the baffle must fill faster than it drains, 
otherwise the design would be useless. With proper design, the level 
in the baffle will always be the same as the tank, no way around 
this. I must finalize the design and test it under real world 
conditions before I can offer more info.

Btw, I'm beginning to think "hot fuel" is not the root cause of these 
problems. Until I can see a mechanisim that scientificaly corealates
to that, I'm not sure I buy into it. Your comments about vaporization 
in the pump are interesting but need further research to explain some 
issues a petro-engineer friend of mine says make it unlikely. Have 
you measured the temp of the fuel at any point?

>>>Excuse my stupidy, but what does MTBF mean?<<<

Sorry, the engineer in me tends to creep out at times. MTBF is Mean 
Time Between Failure. 

>>>I think that the kind of hose you are talking about is the same or 
similar kind of material as the SS braided clutch line upgrade & 
Marty's brake lines. I doubt that you will be able to fit/stretch 
these the same way as regular coolant hoses. It seems to me that you 
would need to attach special fittings.<<<

Yes, compression fittings with ferrules, then maybe AN fittings. No 
hose clamps allowed. The coolant pipes may have to be cut back a 
little to accept the minimum length that can be made up. Overkill, I 
know, but these will never leak or deteriorate. I will modify the car 
in any way to improve my confidence in it, while reducing the 
maintenance issues.

>>>Someday I want to replace my refrigerant lines and am thinking 
that I want to use PTFE? under stainless flex. If this is what I 
think it is, it is commonly used in commercial refrigeration 
systems.<<<

The D uses old "non barrier" type hoses in the suction and discharge 
lines of the R12 system and Dichlorodifluoromethane slowly permeates 
through these. This is why all older cars lose charge over time, even 
if all the other components are leak free. Unfortunately, flexible 
hoses are a must in vehicles, unlike stationary reefer systems. They 
needed be SS but if you ever change your A/C hoses, I would 
definately replace them with the new barrier type. This will leave 
the compressor shaft seal as the only weak spot, a problem shared by 
all vehicles.

>>>I think your opinion is too kind. :-) I'm happy doing the 
basic "vendor approved" modifications; although, I would be happier 
with an entirely new wiring system.<<<

Lol, your talking to a guy who was going to add a complete Halon 
Fire Supression System to the car. Central bottle with piping and 
nozzles to engine, electrical and luggage compartments. Discharging 
would cut main power also. But, I decided its better to treat the 
disease than the symptoms. (I'll still carry an extinguisher 
though :-)

The vendor stuff adresses only some issues. The lack of overcurrent 
protection at sources, insufficent current carrying capacity of the 
conductors used, and poor termination practices all need to be looked 
at. In addition, such design pratices as powering so many things on 
the accessory relay (auto trans computer, A/C system, etc) as well as 
installing CBs downstream of control relays (as in the fan circuit, 
whats up with that?) are an abomination to good electrical design and 
can be easily corrected. (I could go on and on, is that unkind 
enough? :-)

>>> I don't want the next owner to have a hard time figuring out what 
I did differently.<<<

The key is proper documentaion of the changes. As a former machine 
design engineer, I could do better prints than the factory did with 
my eyes closed. Future owners of my car will have no problems 
diagnosing electrical faults, assuming there will ever be many. 
(Problems, not owners :-) Applying aircraft materials, design, and 
testing techniques has always served me well, I trust my life to them 
at my job. This is why the racing folks also use them. Besides, I 
personally feel the car's status is further enhanced by the use of 
such practices and materials.

On another note, my passenger window quit working. After checking the 
switch and power, I had to open the door up to replace the connector 
that had simply fallen off the window motor. Lots of work, just to 
find a bad connector. I suggest strain relieving all that stuff when 
in there or replacing with locking aerospace types. This is the kind 
of thing I'm talking about, designing for reliability involves minor 
details that are often overlooked. Its work, and not cheap, but it 
beats the hassle of standing by a dead car on the side of the road.

Also adding a remote door opening system, this can be done very 
cheaply by modifying a keyless entry/alarm system or shaved door 
handle kit from Autoloc or one of the others on the market. Use it to 
sequence the door locks, which then communicate with the latch 
actuators. This way the doors won't be unlatched unless the locks are 
moved first. I also added a spring loaded popper as its nice to have 
the hood come up on release.

Btw, the entire door locking issue can be resolved simply by using a 
SPDT electrical switch (like a power window switch), removing the 
lock controller and making some minor wiring changes, instead of 
using the manual linkage. The downside in that there is no longer a 
mechanical way to unlock the doors from inside the car (outside key 
still functions) and that would have to be addressed. This is a 
safety issue so I would not recommend it, as every OEM system with 
power locks has some form of manual unlocking. An emergency pull 
cable to the lock linkage would solve this, used only in an 
emergency. 

>>Gary, welcome to the DML. It's a pleasure exchanging ideas with 
technically minded people like you.<<

Thanks (I think :-) My experience is that very technically minded 
people are not always well received, so we'll see what develops.
While my experience with the car is limited at this point, it isn't 
rocket science. Systems are systems, whether in a vehicle or taco 
making machine. I do value others here for their experiences and the 
failure history they can provide, along with the exchange of ideas 
that comes with open disscusion. Purusing of the archives has 
revealed some very good talent herebouts. (Mark Hershey, Darryl, and 
Martin in the UK come to mind, among others.) Unfortunately, my work 
schedule will not permit me to participate very often.

My apologies for the length.

Gary