Sunday, January 22, 2012

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.

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