Fuel System Part 1

Now it is time for some really challenging stuff! I'm posting about the installation of the fuel system but the real challenging part is figuring out where to mount stuff because there just isn't much room in these small race cars. It is really hard to make sure that everything stays out of the way of everything else.  Towards the end of this blog, you will see what I mean!  But first I started with the installation of the fuel cell which wasn't too difficult.  I ended up buying a new fuel cell because the one that came with the car was leaking and it had already been repaired once.  I'm sure it had been in the car since new so it was definitely time to replace it.  The one challenging thing about the installation was the fact that the rivets that I didn't want the fuel cell to sit on the rivets that are protruding through the inside strips welded to the frame.

The rivets protrude just under 1/4 of an inch so I bought a piece of 1/4" plywood and drilled holes in it where the rivets were.  I also put several coats of polyurethane on it so that that it would be resistant to oil, gas, etc.

Now there is nice flat surface for the fuel cell to sit on but unfortunately this also means that it is now sitting 1/4" higher than it was before.  That meant that I had to change the aluminum fuel cell enclosure.  The top portion of the fuel cell cover was broken where it mounted to the chassis at the front so it really needed to be replaced anyway. 

So I drilled out the rivets and removed that piece from the side pieces.  The tops of the side pieces needed to be shortened by 1/4" so I took some measurements and figured out what I needed to change to make that happen.  Here is a pic of the old top piece sitting on the side pieces to show the gap that I needed to get rid of.

Now it was time to draw the new piece on some new aluminum.  I took some measurements from the old piece and made sure that I took into account the areas that needed to change in length.  I got it to the point of bending but I don't have a metal bending brake so I will need to take it over to a friends of mine to use his.

Now it was time to move on to other challenges.  Unfortunately the HPD kit is for a 99 Van Diemen and my car is a 97 so there are several things that are different and one of those things is the fuel cell.  The 99 VD has a very tall fuel cell and you are supposed to install the fuel pump and fuel regulator in a long filler neck that goes into the fuel cell.  I obviously couldn't use the long filler tube so I decided to use an external fuel pump because it would be a lot of work to modify my fuel cell to accept the internal pump that came with the kit.  Here is a pic of the fuel components that came with the HPD kit.  There is also a pic of the fuel regulator that needed to be assembled.

You are supposed to be able to assemble the fuel regulator by pushing the regulator into the housing with your hands.  However, that wasn't working for me so I used an adjustable clamp to try to get it in to the housing.  Apparently I ended up having the regulator at a slight angle and I ended up bending it.  Doh!!  The fuel regulator isn't adjustable and a friend of mine pointed me to an adjustable one that I ended up purchasing and I scrapped the idea of using the regulator that came with the kit.  The HPD kit also came with rubber hose and fittings and I just think that a better approach is to use stainles steel lines and fittings so there are a number of fuel system items that came with the HPD kit that I'm not using.

So now it was time to figure out where to mount the external fuel pump and fuel pressure regulator.  I swear I spent hours trying to figure out where to put these things.  There just isn't a lot of room!!  I wanted to put the fuel pump as low as possible because I was told that the pump will work better if it doesn't have to pull the fuel up a long distance.  Plus it is better to have the weight down low.  There is a nice area right behind the fuel cell and right in front of the motor but the fuel pump was just a little too long of that spot and the pump would have been in front of engine mounting nuts that I needed to be able to check for tightness.  So I decided to mount it on one of the diagonal cross members.  I drilled holes so that I could insert 10-32 nutcerts.  Btw, nutcerts have to be one of the best things invented!  You just have to drill the proper size hole, insert them and then use a tool to compress them so that they expand and stay in the hole.  They give you the ability to use screws to mount different items.  Here is a pic of the nutcerts installed and another one of the fuel pump mounted.

 Next it was time to find a spot for the regulator.  I soon discovered that the bracket that came with the regulator wasn't going to work because I wasn't going to be able to drill holes for the inserts on top of the cross member due to other cross members above it.  So I had to make a bracket that would allow me to insert nutcerts in the side of the cross member.  Here are pics of the bracket held in place with a clamp and the installed fuel pressure regulator.  The bracket doesn't look pretty but it will work!  Unfortunately I don't have the high dollar equipment to make really nice looking brackets.  This one was made from 2" angle aluminum that I mainly cut with a sawsall!

I made a hose up to connect the two and planned on a spot where I wanted to put the fuel filter so that it was in between the fuel cell and the fuel pump and also at a spot where I could easily access it.

Looks great, right?  I went to bed on Saturday evening thinking that I made some really good progress and then in the shower on Sunday I came to the realization that I hadn't taken into account the water pipes that needed to run in front of the engine!!  So most of my work on Saturday ended up being scrapped and I had to figure out where to mount the fuel pump and regulator again!!  Oh well, back to the drawing board.  It turned out that I was able to move the fuel pump up the cross member and I actually ended up making the top nutcert for the pump the bottom nutcert and installed another one for the top.  I also was able to move the regulator to the next higher corss member.  I plugged the three nutcerts that I didn't use with 10-32 screws. Here is a pic of everything re-installed and with the water pipes in approximate location as well.

I need some different fittings to finish the fuel system up and those are on order so I should have them by next weekend.  The only other fuel system item that I messed with was the installation of a fitting to the fuel rail.  The fuel rail is 5/16" and I found a fitting that is designed to mount to tubes.  It has a brass piece that gets compressed onto the tube that it is mounted on when the two pieces are joined.  Here are pics of the fitting before and after installation.

Of course when I was searching for other fittings I came across a type of fitting that is specifically designed for fuel rails!!  Oh well, this one seems to be mounted well (very tight) so it should work just fine.

Side Pods

Since the chassis was a different shape (wider in the back) before Eric's changes, the old belly pan was also wider and the sidepods had a triangular section cut out of them in order to follow the shape of the belly pan.

So, I needed to fill that in.  the bottom of the sidepods is made out of 1/4" plywood with fiberglass over it so I went to Home Depot and got a small piece of 1/4" plywood.  The idea was to glue the cut piece to the sidepod with loctite power grab (construction adhesive) and then put a piece of aluminum on the bottom side and also use adhesive to secure it as well as wood screws.  But first I hand to sand the edges so that there is good material to adhere too.

Here is the piece after securing it with adhesive and aluminum on the bottom side.

The shortest screws that I could find at Home Depot were a 1/2" so I used those and then ground down the points. 

I then smoothed the junction area out a little bit with short strand fiberglass (the green stuff in the pics) and on this particular sidepod I actually had to use it to build up some of the plywood because of the plywood being saturated with oil which caused me to sand it down further than I wanted. I then fiberglassed over the area with some thin cloth.



It was now time to mount the side pods on the lip of the belly pan that extends from the frame.  Unfortunately, this is when I realized that I had forgotten about the small 1" or so lip that is on the outside edge of the sidepods.  I still mounted the side pods and then traced the outside edge of the belly pan onto the sidepod bottoms.

I used a cut off wheel to trim off the outside edge of the aluminum.  Of course I also had to remove a bunch of screws and put a few more in.  I went through the same process of grinding off the pointy ends and fiberglassing over them.  I also put a layer of resin over the now exposed plywood.

Here is a pic of the bottom to show how one of the sidepods joined up with the belly pan.

And here is a pic of one of the side pod bottoms mounted on the belly pan along with a big of both complete side pods mounted.  That's it for now!

Belly Pan

Well, I ended 2011 by working on the belly pan installation and I started 2012 by working on the belly pan installation -- but it is done!!  But first things first, here is a pic of the underside of the chassis after Eric Langbein's work. 

And the first task was to lay the aluminum sheet (.083") on the chassis so that I could trace the frame rails onto the pan. 

And here it is with everything traced.

Next, I needed to cut it but before I did I wanted to make sure that the side pod bottoms would fit because the original belly pan was much wider at the back of the car.  Here is a pic of the belly pan with the side pod bottoms sitting on it.  You will notice that the bottoms have been modified -- that is the subject for the next blog!

I'm actually really glad that I thought of this step because I originally just drew lines that were 1 inch away from the frame rails for the sidepods and found out that the belly pan needed to be wider than that towards the back of the car.  Once I had everything re-drawn, I then used a jigsaw to cut the belly pan.  Next, I used the old belly pan to mark where the existing holes were in the frame rails that didn't get changed by Eric.  This pic shows those holes marked in red but I used a center punch to mark the spots where I would drill the new 5/32nd holes -- those are the small silver dots in the pic.

Once I marked all the holes, it was time to start drilling.  In order to extend the life of my bits, I used cutting oil, one drop per hole for the aluminum and two drops (one at the start of the hole and one half way through) for the steel chassis.

Here is a pic of the chassis after the holes were drilled -- 286 of them!!  The larger holes are the holes that I didn't use and the reason for the strips welded on the inside of the chassis.

Even with the cutting oil, I used up 5 5/32nd drill bits but the holes actually needed to be about a hundreth bigger for the rivets so I used a number 20 drill bit to widen all the holes just a little bit.  A reamer is probably a better choice for this step but I didn't have one the right size.  All of the holes then needed to be deburred and the holes on the bottom side of the belly pan needed to be counter sunk. 

I then cleaned the belly pan and the bottom of the chassis several times with acetone to get all the oil off.  Of course the acetone also removed all the chassis marking lines on the belly pan so after I cleaned it I put the pan back on the chassis and re-traced the chassis onto the pan.  In order to help the bonding material (3M Hysol Epoxy) to stick to the aluminum and the steel, I then scuffed both the pan and the chassis with a pneumatic sander. 

After cleaning the pan and the chassis with acetone one last time it was finally time to apply the epoxy.  My wife, Terry, helped me with this stage.  I laid the epoxy with a caulking type gun on both the pan and the chassis and Terry used a small putty knife to spread it.  We had 2 hours of working time with this epoxy before it started to harden and this step only took about 20 minutes.  We then placed the pan onto the chassis and held it in place with cleco fasteners.  It was finally time to start riveting!  I used high strength rivets that have a 600 lb tensil strength although the epoxy is really what provides the structural rigidity.  Terry placed all of the rivets in the holes and I started riveting.  I borrowed a pneumatic rivet gun and this was definitely a life saver! 



Here are some pics of the pan installed.  I used more acetone to clean up any stray epoxy.

So, that's it!!  One of the biggest jobs for the car done!!