Tuesday, May 24, 2016

Fuel Delivery System

Dateline - 05/21/2016 - Worked on the fuel delivery system this weekend.  The first thing was to get the gas caps installed.  These are a Jaguar work of mechanical complexity.  Talk about over engineered!  They consist of a base filler neck that slides into the tank with an o-ring and screws into the body with four machine screws.  There is a vapor recovery port that needs to have a fuel line connected to it (part of the fuel recovery system I installed earlier (http://leapingv8s.blogspot.com/2016/01/started-on-trunk.html).  There is also the chrome cap which has mounted on it:

  • A lock
  • The lock cover
  • The latch/spring mechanism
  • The Fuel opening seal mechanism

The fuel opening seal mechanism is complex in its own right.  It consists of:

  • A spring loaded plate that mounts to the chrome cap
  • A cup shaped plug that holds the seal for the tank and fits into the filler hole
  • A spring loaded plug that has a rubber seal on it which fits into the cup.  This is used to allow excess pressure to escape the tank.
  • Yet another spring loaded plug in the center of the bigger plug that allows any water that gets into the cup to drain into the tank.

Exploded view of gas cap
YIKES!  Three separate spring loaded components, two rubber seals and a cup that can potentially fill up with water!  All to cover the filler of the gas tank.

So, needless to say, all of these metal parts become very corroded over time, especially the inside of the cup and the components inside.  It took four complete filler caps (the two on the car and two that I purchased on-line) to build up the two I needed.  All of the corroded parts got a good sandblasting and tin plating to help avoid corrosion in the future.

The problematic piece is the rubber seal used on the tank filler.  You can't get this anywhere.  I did some amazon.com spelunking and I think I found a rubber replacement.  I was hoping they would be in this weekend, but they didn't come in.  They came in last night (Monday) and they fit beautifully!  A little larger in outside diameter, but I can cut it back if needed.

The other part of the fuel delivery that I worked on was the steel tubing running under the car to the engine.  I recorded earlier about the steel fuel line from the tanks being crushed  (http://leapingv8s.blogspot.com/2015/10/the-jag-is-home.html).  The crushed piece was were the fuel line ran along the side of the frame rail.  I had cut the offending piece off and was going to just go with the shorter fuel line and a longer rubber line running to the pump.  But with everything installed, I didn't like how close the rubber fuel line would to the exhaust pipe.  So I decided to go ahead and make a new steel hard line that would run along the frame rail to the front, ending closer to the fuel pump.  I got out my trusty pipe bending tools and genned up a piece that fit closely to the frame rail to a good point under the car.  I then cut the existing tubing to fit and used a brass union compression fitting to put the two pieces together.  This left me with a lot cleaner installation, and just a short piece of rubber hose from the hard line to the fuel pump.  Plus, I got a chance to play with my tubing bending tools!

New fuel line and rubber hose leading to fuel pump
My only concern is the proximity of the line to the exhaust manifold and collectors.  I'm going to monitor this to make sure I'm not getting fuel vaporization.  If I do, I'll probably need to get some heat shielding.  It is something to be watchful of.

So this completes the fuel delivery.  I should be ready to put gas in the tanks!  For all intents and purposes, except for a small amount of wiring, the engine should be ready to start!  I need to wire in the ignition and starter buttons, put in fuses and hook up the battery.  I've gone around the car and put electrical tape over all the disconnected wires, so it should be pretty safe.  Maybe next weekend?

Also, I talked to the paint shop and they are thinking the panels will be done this week!  Going to need to plan that panel hanging party!