Back again, although still with little to report. What’s worse is that I’ve got some exams to mark this week so that’s going to make progress even slower than usual.
All the same, after putting the new engine in I put all the wiring back. Of course, this was a lot quicker than last time as everything was cut to the right length. You can see some of the wiring in the photo on the right. Not really very interesting though, being the same as before.
On the right of the same photo is a new expansion tank. The previous one was exactly the same as this, but was a tenner, or something, from ebay. It had always annoyed me in that it was dirty and this brand new one appeared on eBay for the princely sum of £40 so I bought it. I will never understand why some racers buy expensive aluminium header tanks for 3 times this price and which mean that you can’t see the water level without taking the top off. What’s more, it has a connection for the bleed on the top of the thermostat housing which means that the system is essentially self bleeding. Mind you, as you can see, I might just have overfilled it a little.
So that’s the cooling and wiring back together. Next thing was to make the oil system whole again. Most important here was to fix the oil cooler, which was responsible for me losing the engine at the end of last year. So, I went out and bought the most expensive oil cooler I could find. In this case just a normal Mocal one, but a heavy duty one. What’s more, following some advice from Nick, who works with Andy, I put some supports between the top and bottom flanges on the cooler, as in the photo here. The cooler’s back in the car now, although one other thing I want to do is to shroud it a bit more, so that it doesn’t get hit by grot spat around by the rear wheel.
Before starting the engine again I wanted to do one final thing, which was to replace the master switch. OK, so here a photo of the new one, although that there’s a new one down there you can’t really tell. The only reason for changing this is that very occasionally these things wear and they can disconnect when you drive spiritedly over kerbing. (I don’t think the switch itself fails, it’s the little track in the plastic body that the little lug on the key follows that wears. However, rather than buying some expensive silicon like Adrian did, I just replace the things regularly. I rather like reducing the number of failure modes and having a single switch with an air gap is, to my mind, rather superior to a lump of silicon whose failure more is, of course, to go short circuit…
With all that done, I filled up the oil system, took the plugs out to check for oil pressure, put the plugs back in a pressed the started. Brrrrm, brrrrm, it said. That’s a relief.
So, it’s back to trying to make the thing go faster. One thing on my list which is still there after the delays and tribulations over the winter is to make the air box rather better. My idea this 
time is to replace the access panel that’s on the top of the normal airbox with a diffuser sticking up towards the top of the car. I considered making this with grp or aluminium but finally decided to use some polypropylene that I’ve got lying around. I’m planning on making a rectangular cross section duct that enlarges gradually on entry to the standard airbox, at which place I’ll try to put an air filter of some form.
The reason for using polypropylene, which the standard airbox is made of, is that it’s a thermoplastic so you can “weld” it using a hot soldering iron or an air gun. That is, you can stick the duct to the airbox inlet with ease.
As you can see, I’ve only done the top and bottom of the duct at the moment and it’s all held together with sealing wax and string. My fond hope is that when I stick the side panels on it’ll essentially make it monocoque and make the whole thing a lot stiffer. We’ll see whether that works later this week…
In the meantime, the season’s rushing up at us. I got my medical done at the 750 do this weekend so I’m going to stop writing now and fill in the form so that I can get the race licence application in the post…