Nearly ready!

6 03 2015

It is now just 4 weeks away from the first race of the 2015 Mini Miglia Championship at Castle Combe. It’s going to be close to be ready but we are doing our best!

In some ways Combe would be an awesome place to debut the car – it’s a circuit I have raced quite a few times, and it’s very local for me. But being local is a double edged sword as I learned all those years ago when I made my mini7 debut in 1997 because hoardes of friends and family come to see you race, and to be honest the pressure can be something you can do without sometimes – especially when it is your first meeting with a new car, in a championship as competitive as mini miglias. That said if the car is ready, and I have some money left over for the entry fee I’ll be there!

After all the messing about with the MBE ECU we found out that one of the drivers on the circuit board was duff, so sent it off to Ian Oddie at Oddified who specialise in fixing MBE systems. He put it on his rig and tested it – all good as new!

950

With our fixed ECU we went off to JPR Rolling Road in Yate and connected the car up to the laptop and after an hour or so messing about we got her started up and set about the task of mapping the ignition. I was on driving duties so we ran her up, with the intention of starting slowly and then pushing on gradually. Unfortunately, as is often the case we started to encounter some teething problems. We seemed to have an airlock in the cooling system causing the temperature gauge to go into the red, but more worrying than that was the blue smoke coming out the exhaust pipe… A quick check of the plugs showed they were oiling up a bit too. Not happy.

thu 060

You can’t tune a misbehaving engine so we decided to stop for the day. Everything pointed to a valve/guide issue but it was all new so thoughts turned to thinking maybe a ring had broken, or maybe fitted incorrectly. On the drive home I decided to hook the motor out, strip it down, check, double check and triple check everything. It has got to be right – we are going to be racing in the world’s highest profile mini racing series after all.

thu 071

I spoke to Darran at LCP who suggested bringing it up to him in Cheltenham where he could check all the tolerances as he strips it. He likes to do it this way rather than be given an already stripped engine as it is easier to tell what the motor has been doing.

So, we were pleased to discover there was no problem with the bore, pistons and rings. The whole bottom end was given a clean bill of health. The head however was another matter. Darran discovered some rogue exhaust valves which were letting too much oil down the guides. Luckily the head had no cracks and didn’t even need a skim. So a full set of new race valves and new colisbro guides were fitted and all checked on LCP’s valve seal rig. I also ordered a new set of race head studs and bolts, and even changed the roller rockers to some Titan ones.

Another issue on the rolling road was with the trigger wheel on the crankshaft damper. The gap in the trigger teeth was in the worst possible place, and the ECU was having to work very hard to keep up. It was decided best practice to move the trigger wheel round on the pulley so it was the right side of TDC so cutting down on the processing power required by the ECU.

I’ve also done a redesign of the cooling system to eliminate the air lock. We now have a new header tank, and a T piece in the bottom hose. The thermostat outlet now goes direct to the top of the radiator. This is basically a copy of what I used to run in my mini7 many years ago and always worked very well. Time will tell.

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One response

3 04 2015
mowog

Good to see you are still at it. I’m kinda curious what a power curve of a mig looks like. I’m working at designing/simulation work for a new exhaust system for a buddy in Canada who races in the M3 class. See what i’m up against 🙂

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