First Race of the Season - Not

After the carnage of the chain jumping in testing I didn't have much time to get the car ready for the first race of the season.... so some midnight oil was burned.

The other thing Dave Turner does is teach production engineering evening classes and I've been attending "Big Oily Toys Classes" for a while.  so when I examined the diff after the failure at Snett it was obvious that the problem is that the bearing carriers are just two thin in cross section.  this allowed them to twist out of alignment due to the poor shimming.. and carnage resulted.

So using new found skills learned in Evening class and my new Lathe, I made a couple of much more substantial bearing carriers out of some Ali billet... bolted the car together, shovelled out a couple of handfuls of  aluminium swarf, fitted a new sprocket and chain and off we went to Snett to race.

Except we didn't!  Horizontal wind blown rain meant that the meeting was cancelled, and will be rescheduled until June... "Oh Dear" we all said in our best anglo saxon.... in fact many of us were whispering "Thankyou" when Viv Ayres the Clark of the Course made the call to cancel it and saved us from ourselves.

So I've still never raced at Snetterton arguably my home track.

So What's been going on this winter?

After some gentle reminding, and indeed some firm poking with a sharp stick from various readers of this blog I thought I'd do an update and answer the question "What has been going on?".  Indeed even Tim has been poked on his Blog to get me to update mine ... perhaps some people do pay attention after all :-)

So here's a fairly hefty update that will cover (at least in some degree) what has been going on for the last 8 months.

I seem to have spent most of the winter working at the back of the car.  Basically the new diff arrangement has taken a fair bit of time and energy to get right.  But it is finished now.

A rough sequence of activities is:

1. I tried and tried to use the new starter motor that I had left over from the White Van as the motive power for the reverse system.  Unfortunately the motor span in the opposite direction to that required and didn't have enough clearance around the main drive pinion to give me enough adjustment for when the diff moved as the chain tension was adjusted.
2. I then spent a large amount of time drawing up and making  a split sprocket adapter... this worked fine until I weighed it.  nearly 5Kg of additional rotating mass was just too much to carry. So I dumped that idea.
3. Duncan and I spent a long time staring at the arrangement and have now come up with a setup which is just as simple as it can get.   Two bearings a quaffe diff in between and a chain sprocket bolted to that. In fact this is quite an old photo as I now have some new lightened sprockets with lots of holes in them to further reduce the rotating mass.  The chain is tensioned by using aluminum shims between the uprights and the bearing carriers.
4. Reverse is enacted by the winch motor being pulled up into the chain by a tension cable... this is pretty chattery and now is sporting a block of beech above the chain to stop the chin and winch sprocket from bouncing apart. I think I may need to make the actuation a bit more positive b some sort of Cam action in the future.
5. The other major thing we did before the season was to tidy up the bodywork around the roll cage and throw some lovely metallic British Racing Green  paint at the beast.  At the moment only the side pods are done so the car is an interesting two tone red/green.  In fact its been likened to an old Ford Cortina with each wing a different colour.  But hey at least it is distinctive!

Further work on the Diff.

While I've got the Diff unit out of the old cradle, and I'm while working on its mountings I thought I weigh it and see how much the thing weighs. So I dragged the bathroom scales down to the garage (Mrs M had already had a gentle chat about using the kitchen ones :-) ) and shoved the Diff and and reverse starter motor onto them. Total Weight a smidgen under 13Kg. Relative to both the old mounting frame and the blue diff that is a saving of 14Kg. Fourteen Kilos! Finding a single lump of fourteen KGs of weight saving in what should theoretically already be a stripped down race car is incredible and certainly more than off sets losing the convenience of an engine driven reverse.

The old electric driven reverse used to kill then engine due to the load on the starter motor when I engaged it. I wondered if this was because it was an old unit from a scrap yard. I've scrapped my former race support van due to the dreaded Tin worm , but one of the parts I saved was the brand new starter motor I had fitted to the engine. When I fitted this the old Cologne V6 span over  nicely and the new motor drew a lot less power. So I'll try and use the new one for the reverse on the racer,better still it is another whole Kg lighter. It may mean that I'm going to have to make up some new bracketry but I was going to have to d that anyway.

Reverting back to old Diff

Well after four months of shaking off the disappointment of a season and development cycle wasted , I've decide that I do want to race again, and this year I'm going to be ready for the start of the season. So after finally deciding to abandon the other diff it is time to revert to my old one. I'll lose the swanky engine driven reverse, but there's no point in having a swanky reverse if you can't go forwards is there?

Previously the old diff was mounted in a huge steel cradle and all told it weighed in at a massive 27 Kgs. I don't really want to mount it in this way again so I've set about hard mounting it to some new chassis rails I've welded into the engine bay. This is the method that Tim Pell uses now and it seems to work OK, the Chain is tensioned by shimming the diff rearwards from the rails. So for the first time in months I've spent a couple of days in the garage and got some oil in my fingerprints. :-)

I managed to get chassis mods done and the original Diff refitted. This involved drilling and tapping the bearing mounting blocks to take some M10 bolts, and welding in two sturdy 1x2" box section members to a couple of cross members in the engine bay. I'll brace these new members longitudinally to the engine once. I finish fitting the reverse motor. As the drive chain is now being pulled pretty much centrally between the bearings it is unlikely to twist sideways like the blue one and as a result hopefully the Diff will not require any lateral support.

Now If I'm lucky, (and I could do with some) the original driveshafts will also fit. The chain is also shorter by 6 links and that too weighs a surprising amount.

Much Progress- Still Much to Do

Well, its now mid January, and the racing season is rapidly advancing towards me.
In the last two or three weeks I've made a significant amount of progress in lots of areas, but there is still much to do if I'm going to make the first race in early March. The major achievement of the last couple of weeks is that I've completed the initial mouting of the new differential. Unfortunately I've had to construct the mounting from heavy old steel. Hopefully in the longer term I can replace the steel bits that I've fabricated with some nice light alloy plates.

Mounting the diff was a key step on the critical path to getting this beast back to the track. With the Diff mounted I spent a long time trying to get the drive shafts sorted out. Of course with the new diff my old shafts dont fit and so I needed to get some new ones made up. It turns out that my outer CV joints are Escort based and the driveshaft cups on the new diff are Fiesta ones, true to form nothing is ever easy and Mr H. Ford seems to have used a myriad array of different splines to join the wheels to the engine on his various models, this is not helped as on a typical car there will be 4 different sets of splines (diff, each end of the DS and then in the hub.) All of which makes matching a non standard DS to inner CV joint, outer CV joint and the hub a bit of a challenge.

After bemoaning this situation to Aiden he mentioned that he has a couple of Sierra 4x4 front driveshafts left over from the Tiger he is building and that I was welcome to them.

Miraculously they had the correct splines on each end, but were too short. This turned out to be a blessing as I was able to cut them in half and fit them to the diff and hub respectively. I could then link the two with a tube and move the suspension through it's full range of movement. This gave me the total lengths of the shafts (54 qand 56 cms so I guess the diff is off center) So now with the lengths and samples of the correct splines I can get some bespoke shafts made up by GB engineering of Natwich.

With the major headache of driveshafts out of the way I was then able to move on to the next item that had been dependant upon the diff being in its final position; the rear shear plate. You may recall that I had to cut some of the structural bracing out of the rear of the car to get the new diff in. This needs to be replaced and so I'm going to get a rear bulkhead cut out of some 3mm steel and weld it to the remaining tubes. With the diff in it's final place I could now get the dimensions I needed to draw it out in a CAD package. The drawing is now with Peterborough Laser Cut and hopefully I'll get the plate back later this week for welding to the chassis. The large hole on the right is for the exhaust and the larger one in the centre is where the diff pokes through. The indent on the right hand side is to mount the push pull cable that I'll be using to control the reverse mechanism.

Next on the list was a handbrake mechanism. As my old diff also had the handbrake mechanism I need a replacement system. Rather than faffing around making something I decided to take the easy option. Wilwood do some new Powerlight 4 pot alloy callipers with an integral handbrake mechanism. These seem a good place to start, and a careful trial fit of somes seems to indicate that they are an almost direct replacement for my existing Hi Spec units so I need to order some of these and feed the Hi Specs to the ebay vultures.

The last major job that is sitting out on my activity horizon is fitting the new engine to the existing anteater airbox. This is more complicated that for the ZX12R as the CBR1000 has a secondary set of injectors that sit in the airbox, which need to be positioned at exactly the right distance above the intake trumpets. I had planned to use the existing airbox and convert it but Andy Bates of ABPerformance produces a bespoke airbox for the CBR100RR, and a quick chat and visit to seeh him indicates that the CNC milled Ally plates that he uses for the top and bottom of the box can be used to mount it to my airbox, so I've got a pair of them on order as well.