Ready to roll
I've not had chance to do much on my Mighty Mini racer since my last update and its appearance at the Autosport Show in January. It's been dumped at the back of my unit as a nonrunner for months, with no flywheel after an appointment at Slark Race Engineering to get the timing sorted out had to be cancelled.
I had to miss the first round of the new season at Brands Hatch due to family commitments, but I had booked in to race at Cadwell Park in May, so I set aside a few days to get the last few bits sorted out in time. First up was the engine. Despite being a fully rebuilt unit, I and others had noticed it was burning some oil on the overrun when I did the Mini Sport Action Day at Castle Combe. After a quick call was made to James, the engine builder, we hatched a plan to remove the cylinder head. We initially thought the problem was simply down to poor valve stem seals, but James took it away with him anyway to double check everything, and it was lucky he did, as he found a few of the valve guides were also worn. A new set of guides, oil seals and a set of recut valve seats later, all should be well.
Next up was that visit to Neil Slark at SRE in Amesbury. When he set my engine up for the Action Day last year, he suggested that there may be more power and torque to come from advancing the ignition timing. Unfortunately on an SPi this is ECU controlled, and moving the distributor makes no difference. The flywheel has to come off to enable the sensor ring to be modified and make it adjustable.
With this done I refitted the flywheel and Neil ran the car up on the rollers to get a baseline figure, before removing the starter motor and moving the sensor ring to advance the timing. With some trial and error we managed to arrive at the optimum setting, and Neil then ran the car up for the final power run. The result of all this work, along with some minor fuelling adjustments, was power and torque figures comparable to the front runners. I'm chuffed to bits – let's just hope my driving is up to it too!
With the car back at my base I then turned my attention to sorting some minor problems. The car had been getting too hot when stationary at the Action Day, which I put down to the radiator I had fitted in a rush when I found my original item had sprung a leak. The replacement I had fitted was a two-core item of unknown heritage that I'd found in my spares stash. A closer inspection revealed it wasn't in its first flush of youth and was full of all sorts of
Neil Slark puts Ryan's racer through its paces on the rolling road.
With some careful timing and fuelling adjustments made, performance was much improved.