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.

Long Time no Post- so what happened?

After the Brands meeting I took the racer to the following meeting a Mallory park in early June. Here again I suffered major overheating problems. Mallory is a lovely short circuit, I qualified last, and in the race I managed to keep with the slower members of class C for a couple of laps but eventually I had to start short shifting again to control the engine temp and lost touch with them. So running glacially slowly and treating it like a bit of a test I also finished last and was lapped by everybody else in the field at least once. Not a good day.

So I took it home and set about building an oil cooler & air intake in the left side pod, using a take off plate provide by Colin D from the paddock. This took me a while and as we had four or five weeks before the next race I took my time and I'm pretty pleased with the result. This is a 40 row cooler, so it had better keep the damn thing cool.

So I was looking forward to the Double Header at Cadwell at the end of July and it seemed that finally I might have a chance of going a bit quicker once the thing was being kept properly cool, by the oil cooler.

This was not to be, When doing my pre race checks the week before Cadwell I discovered a full 10mm of play in the Diff output bearings on one side.

Obviously I couldn't race like that and with 5 days to go before the meeting there was no possibility of getting it repaired either... So that's another set of entry fees wasted.

After losing half the season to rebuild, engine swap and diff change, along with all the blood sweat , money and tears. Only to be much much slower than I was before... I'd had enough, and simply closed the garage doors and went inside to consider if I really wanted to carry on doing this racing lark as it was offering me precious little fun at the moment.

For those of you interested in the gory details this welded globule of steel is all that is left of the needle roller bearings that should be restraining the output shaft from the diff. Ohh I think that has got a bit hot!

So that was it for the season, Unfortunately I've been unable to get the diff repaired as the very nice chap who loaned it too me is simply swamped with work. I've basically had four months off and ignored all things race car related to try and rustle up some enthusiasm again or decide to give the whole thing up.

Still I have save a few quid in unspent entry fees.