Autotech Academy Motorsport: The hole job

The U bend was put back on the toilet and after fixing the 90deg bend to flat board and covering in masking tape, Dad layed up a few layers of fibreglass to create a flange to join the bend and airbox (sorry no pictures). After some trimming, sanding and drilling the flange was mated to the 2 parts as seen below.

It was then just a matter of bolting it on the spacer and making up an aluminium support bracket. We are pretty pleased with how it has turned out, very secure, neat and hopefully give the best breathing possible (based on the bike design)

The height of it all does look very menacing and we were wondering how much bonnet was going to have to be cut out and how it would affect my field of view! This engine is one of the smallest due to the lack of secondary injectors and variable trumpets in the airbox, the later R1 is much taller.

I am getting a new bonnet to build up a plug for a new design that will be more accommodating for the modern injection bike engines, but for now we will just cut a hole in the bonnet. To do this i copied the shape of the airbox on to a piece of card, cut it out, placed it over the engine and marked up where the bonnet pins on the chassis were. I then aligned the template with the bonnet pin holes in the bonnet and transferred the cut out onto the bonnet

The first problem we encountered was that with the front of the bonnet wrapping under the ducting for the radiator it was almost impossible to lower the bonnet over the airbox, and once it was on the hinge it definetly wouldn't work. There were 2 options, make the hole in the bonnet bigger (longer) or cut the lower edge of the bonnet away. We are creating a new lower front end for the bonnet to incorporate a splitter which would mean that a hinged bonnet would not work any way so it was decided to cut out the lower section.

The wooden spars are still entact to attach to the hinge bracket if we need them, but by adding 2 bonnet pins to the top of the upper wishbone chassis mounts, it now now ,means the bonnet lifts on and off easily, rather than the scrabbling around trying to get to the hinge bolts.

Now that the bonnet could be lowered on properly, it became obvious that a lot more of the bonnet needed to be removed!!! First off the choke and secondary throttle position sensor fouled the bonnet, so this was nibbled away, then the throttle cable mount, AIS valve and breater pipes started touching so this required more cut out, then the coil pack on the front spark plug caught, then the 2nd, then the 3rd and then the 4th, and finally the front top corner of the cam cover fouled!!And this is how we ended up with this whacking great hole!!!! So much for a neat little hole!!!

The bonnet must have been 20mm thick in places due to all the repairs and graftings of bulges onto it, and i reckon i have cut 3kg of weight out of it! New lightweight body work is definitely needed!!!

Even though its only temporary (maybe the entire season temporary!) the hole needed to be covered to meet the regs. The bonnet is all over the place in this area due to the curves and existing bulge for the old airbox, so the initial idea of forming an aluminium panel over the top was not looking easy. It was decided that a fibreglass bulge would be the easiest, but how could we form something over all the bits and bobs on the engine. Hunting around the garage and workshop we found some thick foam (from the base of an unused seat from the the bus) and trapped it under a plastic bag between the bonnet and engine so it covered and formed its self over the bumps and knobs of the engine. The trouble with this was it was still a bit too uneven and left an abrupt edge between the hole in the bonnet and the protruding foam, we needed something flexible and flat to smooth the foam out, this was found in the form of a piece of carpet!! With this trapped under the bag, between the bonnet and foam laid on the engine it gave a nice smooth bulge. We then used masking tape to blend in the curves and reinforce it, and covered the boinnet in plastic to protect it from the up and coming GRP resin.

3 layers of wet CSM matting latter and we had a pile of sick on a bonnet.....

A few hours latter and a bit of trimming we had a mould for the bulge. After some prep and further trimming of the bonnet this will be temporarily attached to the bonnet and a couple of layers of fibreglass laid from the inside of the bonnet to create the bulge.

Another job i needed to do (and another reason not to start the wiring) was to fit a cat. I had an unused cat and sleeve of Tim Cheeneys in my garage, and he said that i was welcome to use some of it as long as he was left with a usable piece aswell (thanks Tim!!). I simply cut it in half to produce what is shown below.

I drilled 3 holes in the sleeve and used steel pop rivets to attach it to the end of the exhaust. I can quickily and easily drill these out to inspect the cat at race meets if i suspect the cat is failing or blocked with wadding.

It is getting desperately close to only having the wiring left to do so i was scrabbling round looking for mechanical jobs to finish. A new tunnel top was required......