17 August 2008
Found a guy on ebay selling some nice billet alliminium oil catch tanks at a very cheap price (£35 including P&P!). When I got the tank I could not fault the quality however the bracket to attach the tank was little more than an after thought. The bracket was sheet steel formed into a right angle which would attach on one side of the tank with two little screws and rivetted to the bulk head with two rivets. I was not impressed with support on one side only but further more the length of the bracket would mean that the tank would be held off the bulkhead some several miliimetres so it would not be very secure. I thought about a better way of doing this and headed to my local fabricator and welder and instructed them to tig weld a bracket to the tank.
Photo below showing the tank rivetted in place on the bulk head with four rivetts, that's going nowhere! On the scuttle you can see the flmsy after thought of a bracket that came with the tank. The tank also has a sight glass so that the oil level can be clearly seen. The tank also have two inlets which is better for a V8 configuration having two rocker covers.
31 August 2008
Session 269 - fuel injector wiring
Extremely busy times at work preventing me making real progress on the car at the moment. Today I managed to commit 5 hours to the Westfield.
Today I desgined and made up the loom for the fuel injectors. I had ordered some good quality cable from premier looms. Its amazing how much better this cable is to sa y the typical after market stuff you get from Halfords for wiring in ICE. This cable is proper thn walled high temperature and oil resistance. This high quality cable looks small for the current rating compared to the cheaper stuff but this is because the wall is thinner and also the copper core is higher quality and multi-stranded. Anyway that's enough about cable, starting to sound obsessive!
Spent about an hour thinking about the wiring of the 8 injectors, there are options believe me, serial or parallel for instance. More than that the ECU I am using, megasquirt uses two injector drivers. So the injection is batch firing that is to say they all fire together irrespective of which cylinder is receiving the spark. There might be an option to sequantially control each driver. So do I simply wire up each bank to a controller? I thoguht about this for a while and decided that it would be better to wire up each injector so that it is on alternate drivers in the ignition fire sequence this give me two main advantages I can think of, 1) if I can sequentally control each driver then this gives me the opportunity to tune the fuel injection phase and 2) if one controller stops working then I lose power on odd or even firing sequence no one complete side of the engine which would cause major damage to the engine.
So to compress four hours work into a couple of sentences, this is what I did. I measure the distances between the injectors, the spacing is not the same as the two inner inectors are closer. From this I drew a wiring diagram and worked out the inter-sections that needed soldering and the lengths of wire needed. I want this loom to be very tidy and close to the injectors.
I then proceeded to solder up the wires. Rather than have a three way spit of wires at each section I spliced of the outer insulator at various positions on the length of wire and then simply soldered a short section of wire to go down to the injector. This took time and precision to achieve but the result is good conductance and a mechanically very strong joint. All ends were tested with the my digitial multi meter. Each bank or loom has three coloured wires, pink, I know, couldnt get red to the correct spec, for 12v supply. Green for injector driver one and Blue for injector driver two.
Cables were held together at regular intervals with pvc tape and then once the position verified I used proper loom tape to cover. Tie wrapped at the ends. I am all going to get some convoluted tubng for extra protection and good looks. I checked the looms for short circuits after looming up just in case.
I decided to leave installing the connectors for pluging into the inectors for another day.
Photo showing my design for the injection loom. To the right you can see the right bank loom placed on top of the injectors illustrating he loom matching the position of the injectors.
Photo of the other side showing the left hand side loom, again positions are good.
Go to November 2008