Back to work.

Fuel tank installation continued:
This write up isn't in chronological order so some of the pictures might look out of order. I think it makes more sense this way.

With the fuel inlet completed next up is to prep the tank. I'll need to to add a fuel standpipe, a vacuum vent and fuel level sending unit. Start with the sending unit.
It's a "VDO Gauges 226001 - VDO Fuel Tank Senders". Currently $26.95 at Summit Racing where I bought it.



The sending unit will be mounted on this platform part of the tank.


To drill through the tank I'm going to use this hole saw.


It's the same one I used to drill through the side of the van for the fuel inlet. At the time I wondered if I was going to need it again. Turns out it's the perfect size for this too.

Start with a pilot hole at the center of the mounting platform.


Then use the hole saw but keep the drill at a slow speed.


Done.


Use a curved file to clean up and smooth out the edge of the hole. Then follow that up with some sandpaper.


Here's the view down into the tank through the new hole. Fair amount of metal filings.


After several rinses at the utility sink it comes out looking clean.


continued -

 

Fuel tank installation continued:
To attach the sending unit to the mounting platform I'm going to to drill and then tap five holes on the platform. Tapping the hole will create threads that will hold machine screws. The screws then hold the sending unit in place. Here's the wiki page about taps and dies.

Since I'll only get one chance to get this right I better practice before drilling into the tank platform. I'll use the left over metal from the circle just cut out along with one other essential tool.


That tool would be "Pocket Ref" by Thomas J Glover. A small paperback with an amazing collection of information. While typing this up I went to find a link for the book (Amazon link-4th edition) and see that the 4th edition has just come out. Since I was using the 3rd edition I just ordered the new one. So this write up has now just cost me $12.05 (including shipping). I'll keep the 3rd edition in the van.

I'm going to use #10 machine screws since they are the largest ones that will fit through the sending unit's cover plate. I have both #10-24 and #10-32.


The second number refers to the number of threads per inch. The #10-32 is called a fine thread. I'll be tapping a hole into thin aluminum which doesn't have much holding power so I'll be using the #10-24 screws (coarse threads). There are less threads per inch but the threads are thicker so should grip better.

Open up the Pocket Ref and find the section on tap and dies. On the left side find the screw #10. There are entries for both 32 and 24 threads/inch. Look at the entry for 24. Under the heading "Drill" you'll see the number "#25".


The number "#25" is the drill bit gauge. My drill bits, and most probably yours, aren't sized by gauge but by fractions of an inch (or metric) so need to do a conversion. Find the pages for conversions.


There is no direct conversion for a #25 drill bit to any one I have on hand. Want to use the next closest size that is smaller so look up the chart to 9/64 which is a drill bit I have.

Before drilling use a punch to create an indention so the drill end won't wander.


The hole that will be tapped should be as straight as can be managed. To help out I'm using my combination square.


Remove the ruler and use just the head as a guide to align the drill bit.


Set the bit right into the ruler groove and check from all sides. Then slide the square head back and slowly start drilling keeping the upright angle.


Here's the tap and die set I'll be using which I recently inherited. Dies are the round objects along the top of the set. They are used to add, or fix, threads on a screw. Below and holding one of the dies is the die wrench. Below that are series of taps. And at the bottom a tap wrench.


I'll be using the tap wrench and a tapered tap that is marked for #10-24.


Assemble the tap and lubricate it before using. I'm using the stuff you find at the bottom of a can of Vienna Sausages to lubricate the tap.


Just Kidding!
Look in the Pocket Ref.


The recommended lubricant for the threading of aluminum is "Soluble Oil, Kerosene & Lard Oil". Lard Oil? I don't know what it is but bet there's some of it at the bottom of a Vienna Sausage can. Maybe I wasn't so far off the first time.

I'm really using the Vienna Sausage can to hold some kerosene.

Use the square head to align the tap.


When it looks good start rotating the tap wrench.


Apply a steady pressure and most importantly keep the tap going straight. Once you get the tap going you're supposed to rotate it in reverse every couple of turns to break off "the chip". With something this thin that didn't seem to be much of a problem.


Back out the tap and check the work by threading in a machine screw. Check out the alignment.


Looks dead straight to me. By the way, you're looking at the first hole I've ever tapped. I checked with my Dad about which kind of threads to use in aluminum shortly before he died but most of the other info for this I got by reading.

Something else I read. After using a tap you should "Clean the swarf from your flutes". Here's a picture of one of my flutes covered in swarf.


Don't know about you but I can't say that out loud without adopting a bad Swedish accent. From now on when asked where I've been or what I've been doing the answer will be, "Been cleaning the swarf from my flutes."

One more thing to check. Tighten the screw in all the way then keep tightening until I strip out the threads I've just cut. This way when it comes time to attach the sending unit I'll have a good idea of how far to safely torque the screws.


Tap three more holes and strip them out for practice.


continued -

 

Fuel tank installation continued:

I now have some practice with threading holes into thin aluminum but before starting on the tank I'll have to figure out how to place the cover plate for the fuel sending unit. Here is the sending unit. Notice the round plastic float attached to the brass rod.


That float extends off to the side of the sending unit. Looking at this diagram of the fuel tank.


The platform for the sending unit is at the right end of the tank so I have to be sure to install the sending unit so the float extends to the left.

This sending unit is made to be used in tanks with a diameter of from 6 to 23 inches. It has to be adjusted to match my 8" diameter tank. First step was to disassemble the different pieces.


In the picture you can see the cover plate with the main rail. Laying above it is the extension rail and above that is the black rectangular sending body.

Here is the measurement diagram in the instructions. This shows how to position the sending body and the length of the float arm


Need to find the dimension "A". Measure the depth of the tank from the sending unit platform. 8 - 1/2" deep.


This is supposed to be an 8" deep tank so the platform should be 1/2" high. Double check.


Here is the table that corresponds to the diagram. The "A" measurement is 8.00 so that gives 4.00" for "B" and 4.90" for "C".


The "B" setting is how far down to place the sending body. Have to add 1/2" to the "B" dimension to account for the raised platform. The extension rail won't be needed so mount the sending body to the main rail. On the sending body, measure to the anchor point for the float arm.


Next the "C" setting. This is how long to make the float arm. The table shows 4.9" which using "The Pocket Ref" translates to near 4-7/8". The instructions have you add one inch to that length for the anchor point. Measure and then mark the correct length with tape.


Cut the float arm and then mount to the sending body. The float must be to the right of the sending body.


See if it fits.


It does, just.

continued -

 

Fuel tank installation continued:

With the sending unit correctly orientated on the tank, carefully mark the cover plate hole locations.

Using the exact same techniques that I used with the practice cutout, drill perpendicular holes into the tank platform.


Then tap them.


Test fit the new holes with screws.


After the drilling and tapping of the aluminum there is this small debris leftover on the underside of the surface. It can be seen in this picture of the underside of the practice cutout. I guess you'd call those leftover bits "hanging swarf". Good name for a comic book villain.


Need to remove all the hanging swarf before continuing so none will get into the fuel later. Use sandpaper on the underside of the platform till all the swarf is knocked free.


Take the tank to the utility sink and keep rinsing out until there is no more debris inside the tank.


Install the sending unit along with it's rubber gasket and screw it all into place.


Seeing how this is the first one of these I've ever done I thought a test was in order. Stood the tank on the end and then poured in enough water to totally immerse the sending unit. Checked for leaks. Found one.


It's a weeper right at one screw head. While the tank is in use the cover plate won't be immersed so this small leak might not be a problem but I didn't want to take a chance. Removed the leaking screw from the hole and waited till everything dried out. Then coated the hole and the screw in gasket sealant.


Wait until the sealant is tacky then put the screw back into place.


continued -

 

Thank you for documenting this work.

 

i gotta agree with henry, you have done a fine job documenting this build. many people (me def included) don't spend the time to document what seems to be so simple - like threading holes and the need to use the correct size bit. stuff like that. it really helps the less practiced among us on the forum.

i can't say that everything you have done is the way i would do it, but it is your van and your style that you are building to, so thanx for helping out the forum. and that applies to all on the list who put out the effort to document and explain their projects. we all benefit - i know i do and i have been turning wrenches for 36 years.

ok enuff mushy stuff. get back to it WVvan! btw the grey gasket sealer looks like yama-bond. or honda bond sez neil w/ the 654cc BRP! do i win a prize?

 

I recently got myself a Quigley E-350 Extended and have been searching far and wide for a thread like this. Thank you!
I am going to start paneling in my walls back in the cargo area, and found your pages on this to be most informative! With all the different surfaces I have to deal with I'm a bit intimidated, but I am starting by lining the walls with Megamat sound deadener as I intend on installing an audio system, and I haven't found a better product to eliminate road noise and vibration from hi output car audio systems. After that comes insulation and paneling.
I'd love to see what you did around the driver side window in the back, as I have 3 large windows in my cargo area that will make things interesting and this is my first real conversion project.
I hope to post a build thread on it after I've completed a few things so I can show some progress. I will refer to your pages often, and Again, Thanks for all the hard work sharing your experience, I find it invaluable!

 

Hey Guys,
Thanks for the kind words and encouragement. I do appreciate it. With the weather what it is now working outside on the van is going to be a real chore.
If I was to start from scratch there's a bunch of stuff I'd also do differently but since this is the first one of these I've done it's a learning experience.

The gasket sealant is Permatex 9AR. No prize for you.
That makes two of us since I've not done it yet. Like you I'm not sure how to go about it. I've got a few ideas but like alot of stuff on the van, don't know what's going to work until I really dig into it.

 

Fuel tank installation continued:

With the sending unit installed some info about how it works.
In this picture you can see the float attached to the sending body. Within the sending body is a variable resistor. As the float rises and falls in the tank with the liquid level it changes the resistance value. The wires from the sending body connect to the two terminals on the top of the cover plate.


Here is the box the sending unit came in.


The check mark next to "10-180 ohms" shows the upper and lower limits on this particular sending unit model.

The resistance value should be 10 ohms with the tank empty and 180 ohms with the tank full. You can buy stock fuel gauges that correspond with these values. I'm going to go a different route for a fuel gauge so I need to take some measurements.

Move the fuel tank over to washing machine next to the utility sink. Hook up the probes from my voltmeter to the electrical connections on the top of the sending unit cover plate.


With the tank empty the sending unit returns a value of 8.8 ohms.


Since the fuel inlet is on the side I'd roll the tank over to pour in water. Used a milk jug as my gallon measure.


By the way, the top of the washer looks like it does because it's next to the utility sink so paint brushes and such get placed there while waiting to be cleaned. I like to think of it as my on little piece of abstract art.

After adding each gallon of water I'd roll the tank back and straighten it up with a level.


So I added one gallon of water at a time and took a new reading with each one.

Here's the results.
Gals - Ohms
1 - 30
2 - 67
3 - 101
4 - 125
5 - 143

Once I poured in 5 gallons and leveled up the tank the water was just even with the bottom edge of the fuel inlet.


Dumped the water into the washer and moved the tank back to the workbench. Added a couple ring terminals and shrink tubing to a dual length of wire. Attached this to the cover plate terminals. With a resistance reading there is no positive or negative so don't have to worry about which wire is which.


You can tell that the gasket sealant is still a little tacky.

continued -

 

Fuel tank installation continued:

Now that the sending unit is finished I have to add two more items to the fuel tank before it will be ready to install. Need a way to draw fuel out of the tank. There are ready made fuel standpipes that screw into the tank but I think they are overpriced. These heaters are a specialized device and there are no outside manufacturers making replacement parts or installation hardware. Without competition the manufactures can charge whatever they want. My major complaint. Time for DIY.

Here's the parts I'll be using to make my own fuel standpipe.


Plastic fuel line. It's 4mm OD and 2mm ID.


Flexible Copper tubing. 1/4" OD.


1/4" x 1/8" Hex head bushing and steel brake line.


The bungs at the top of the fuel tank have a diameter of 1/4". Need to reduce the size down. Use Teflon tape on the hex head bushing.


Install the bushing onto the tank.


My original idea was to use steel brake line as the standpipe since the end fittings match the inside (1/8") of the hex head bushing. On reflection I wasn't sure how the coated steel of the brake line would react to being continually submerged in kerosene so I moved to plan "B".

Use copper tubing as the standpipe into the tank. The heater installation instructions warn that air bubbles could form within fuel lines larger than 4mm. These bubbles could then block fuel flow. So I'll take the 2mm ID plastic fuel line and slide it into the copper tubing. The plastic fuel line fits nicely into 1/4" OD copper tubing.

I'll still use the brake line fitting but it needs to be drilled out before the copper tubing will fit through. Start by drilling a hole in a block of wood. Screw the fitting into the hole.


Set up the drill press. Use clamps to hold and center the fitting. There's not much room for error so took my time with this step.


I've written before about using my drill press on metal but I forgot this step. There are a set of pulleys on the top of the drill press used to adjust the speed.
When drilling metal I change it from the fastest setting.


To the slowest setting.


Drill out the fitting.


Drilled fitting on the left.


The copper tubing now slides through the fitting.


continued -

 

WV: Are you going to install 1 (or 2) vapor valves?

 

I'll be installing a vacuum vent but not a pressure vent.

 

I always thought that when filling the tank, vapors need to be vented to somewhere else, to relieve the pressure in the tank, no? Somewhere down the line (70s I think), Evap Law mandated that these fuel vapors cannot be vented into the atmosphere.

I am not sure in WV, but I was told long ago that in NY you need to connect the 2nd fuel tank to the Emissions System, i.e. vapor line needs to go the charcoal canister, etc. etc.

 

I'm hoping that if the tank is filled slowly the displaced air will escape via the inlet hose. I'll find out the first time I try to fill it. If it doesn't work, I'll figure something out.
We don't have emission checks in WV so there is no worry about where the tank vents. Even if there was I don't think that you'd want to vent kerosene fumes into a gasoline engine's emission system.

 

This is true for gas, but not diesel. Diesel vapors are orders of magnitude less volatile than gasoline fumes. There should still be ventage, thru the filler neck is probably OK due to the non-restricted size vs. unleaded, but vapor recovery is much less an issue than with gasoline.

Edit: Replying to the vapor recovery post above. After reading again, diesel = kerosene. (prety much interchangeable, lots of small differences with additives and taxes, but more alike than not.