Broken bits of metal

With the rolling chassis all apart and off for refinishing I've turned my attention to the engine.  I'll be performing a full strip down on it so that I can be confident in it's reliability during the National Rally next year.  Being a bit tired after work (and it's only Monday!) I set myself the easily achievable target of removing the top end (rocker box, cylinder head, barrel and piston).

No surprises with the rockerbox removal, apart from the gasket between it and the cylinder head.  It was so think it looked like carpet underlay!

The cylinder head was an easy removal too, uncovering a slightly coked up piston and very oily bore.  The latter has me thinking that a rebore and new piston maybe in order.  Fortunately I have six spare barrels and at least as many pistons.  Hopefully there'll be a match in there somewhere.  A job for another evening.

Next to come off was the barrel.  It has some discolouration in the bore and some light scoring, but it isn't too bad apart from one scratch.  Looking at the piston though, it was immediately apparent that the gudgeon pin circlip had been poorly fitted on one side.  It wasn't sitting fully in the groove in the piston and, when removed, was oval after all the years of sitting in the incorrect position.  The next thing to happen was the biggest surprise though, and underlines the importance of performing a full strip down on restorations to give a known quantity in terms of the engine.  The main piston ring fell off!  So the top ring was broken (which probably explains the scratch in the bore).  Maybe starting her up at the very beginning of this project wasn't such a good idea!  The broken ring probably explains the oiliness of the combustion chamber as well.

So with a few nasties uncovered, it's time to call it a night.  Lots more investigation to come and I'll be especially careful in my inspection of the rest of the engine.  Although the engine cases haven't been off it has clearly been exposed to a bit of abuse in it's 10,000 odd miles.