Following on from Lizzie’s epic(ish) journey around South, Mid and West Wales, a minor setback has occurred. On Sunday Lizzie decided to throw a spanner in the works and start producing a horrendous tappety type noise. This would need investigating.
So the first that was checked was the cylinder compression. Not long ago this was 105 PSI on all cylinders. Cylinder 3 was down at 0psi, not good!! Given that this could be a sticky valve, a start was made on checking the valves by looking in the valve chest.
For those not familiar with this type of engine, the valves are on the side of the engine, neatly hidden behind the inlet and exhaust manifolds, therefore, the first job was to take off the carburettor and the manifolds before taking off the valve cover.
A look down the through the spark plug holes with a borescope proved inconclusive, we could see the valves moving but not much else. Sounding like something from the dark ages, the phrase “off with her head” was heard from a few people I spoke to via social media, so this was the next step.
To take off the head entailed the removal of the HT Leads, the distributer, the top hose (following the draining of the cooling system), heater hoses and 14 carefully torqued down bolts. The bolts needing that extra bit of leverage before deciding that they would like to come out for a bit.
Drum roll… what will we see… a stuck valve? a fractured valve? a fractured piston? With the head off and on the bench a look around the top of the block did not reveal anything. The engine was turned over by hand, everything looked ok, a bit coked up with carbon deposits but nothing obvious. A look at the head then showed the problem…
Thankfully the damage is confined to the gasket, which has blown through, as can be seen in the above photograph. A replacement is on order and is due to be delivered in the next few days. This will give us time to decoke the engine (removing the carbon deposits) and checking the tappet clearances to make sure they are withing tolerance, hopefully meaning that the engine will be good as new when it is put back together – watch this space for news on that.
