Monday 19 June 2017

Cleaning The Pistons and Con Rods

Spring 2016/17 was spent cleaning everything up. Little to report. It was just a slog. Sorry - not many helpful photos......

With the con rods removed, I tried soaking the pistons in four different solutions to loosen up the baked on oil and carbon: petrol, diesel, 'Gunk' and 'mek' - a very nasty chemical used for cleaning in the aircraft industry.

Mek performed the best. Petrol was okay. Diesel not so good and Gunk was useless.......it just STANK!

Meanwhile, con rods, caps, cranks, bolts, nuts, and circles were all cleaned in Jizer -  a recommendation from Richard's wife - Helen.

In March 2017 I researched, then bought, an ultrasonic cleaner. I got the biggest that my budget would allow: a 9 litre model. Any smaller and I probably wouldn't have been able to fit parts in it.
Test Fit of Carburettor - March 2017
Once parts and been initially cleaned in Jizer, I ran them through the ultrasonic cleaner using a diluted cleaner intended for carburettor cleaning - as I planned to clean the carburettor in this way at some point and it would also be be suitable for the pistons. The results were very pleasing. 

All parts cleaned in this way were rinsed, dried with compressed air, (and a hairdryer!) and, since they were now prone to flash rusting, then given a generous coating of WD40 before being stored in clean tubs - all labelled up of course. 

Through this process I realised that the liners from my DX2 engine were too worn to use. The DX engine liners also looked badly worn and, anyway, one of the liners still had a piston stuck in it. 

I was sharing my woes with 'Badabec' on the CCC website forum and he generously offered me his cast-off set of pistons and liners from his D Super 5 - left spare following his own major rebuild. I collected them from Peter - for that is his name - at the D Section rally in June 2017. It was nice to put a face to a name and Peter showed me the ingenious heater valve modification he had made using an in-line heater valve from a taxi.


Soon after the rally I had the pistons and liners assessed. Although there was a bit of lipping on the liners (at the top of the piston stroke), the feedback was that they would need little more than a good hone - which I had done. I ran the pistons through my ultra sonic cleaner and they came up very well. With the liners honed, I took a wire wheel to the rusty outsides.

By mid July I was good to go: I would use the pistons and liners that Peter had given me. I only had to resolve a nagging doubt about cylinder head gaskets and I could start to rebuild.........