Riley Pathfinder

Formhalls apprentice Simon starts his oily saga

Danny invited myself and my boss, Charles Tanner, along to last year’s

Practical Classics Classic Car and Restoration Show with the expressed aim to strip and assess the Riley 2.5 litre engine that he’d ripped out of his project Pathfinder. We agreed, and packed the tools.

At the show, we were suffering slightly from man flu of various varieties, but we still managed to strip all the outside covers along with rockers and posts, followed by manifolds and carburettors and then the cylinder head.

Chatting away to showgoers as we went, the process was slow, but organised. As we worked, we put each set of components into its own tray, ready for assessment and cataloguing. We began to get hopeful. All the studs removed as well as plugs and nothing, so far, had seized which was remarkable given the way that the car had been stored and the fact that one of the core plugs was missing. Next was to remove the valves and springs from the head. By the end of the weekend we had all the ancilliaries and the head stripped and the short engine and gearbox split. The whole shebang was taken back to Formhalls’ HQ for cleaning and further deconstruction. This was where the real work would begin.

Time to get serious

First the head was given an ‘install’ rinse off in the wash tank. All head studs and oil pipes were removed from the block as was the timing chain and tensioner and associated gears. Then the engine was flipped over and the fly wheel came off. Here we discovered our first small issue – a stripped thread in the crank, but we taped it and it was recovered. The sump, had the gunge scooped out it, I measured a good couple of inches (eww), followed by the oil pump and drive. There then followed the cam shafts and bushes. This posed a bit of a problem as we fought to get the oil pump drive bush out. I fabricated some plates and bars to drift out both this and the camshaft and rear bushes.

‘The pistons came out without the need to use the biggest hammer’

Next I approached the cam followers, which where pushed out the top of the block. None of them were seized, which was a bonus.

Then came time to extract the rods and pistons that came out the top without the need for the biggest hammer! Sadly they came out with a few broken rings exposing scoring in the bores – all machinable though. After that was the crank which, we were relived to discover would ‘go again’ with some work. All the parts that could be rinsed off were and then they were catalogued.

Assessing the engine was challenging.

We were trying to see if it had failed in service or if the ring damage was due to fouling during deconstruction. Judging by the other parts it looked to be normal wear and tear plus two broken rings that had not been run for long, but had scored the bore on their way out a fair bit. Rebore required. We discovered the engine was still on standard pistons when we dug some of the carbon build up off the top of them. We also found some fairly heavy scoring on the thrust side of the pistons, but again, nothing too out of the ordinary. The rod bearings had obviously lived a life, but there was no excessive play. Again, the timing gears were in good condition, but the guide plate needed a new fibre pad.

The upshot was, once we had it in pieces and the first basic clean done, we came to the conclusion that the Riley engine was not too bad – but clearly needed some serious TLC.

Washing up

Starting the rebuild, we identified the elements that needed renewing, including bearings for mains and rods. Getting these sorted would mean we would know the size do grind the crank to. Once in we then had to bore the conrods bay a few thou and finish on the hone to ensure the accurate size and fit. This engine is different to most of the lumps we deal with as it uses conventional shell bearings as opposed to white metal. We’d also be fitting new modified

nibs in the block and connecting rods to suit the new bearings. As we began the process of procurement, we were removing crank plugs and cleaning the crank out, something that so many miss out or don’t do thoroughly enough. Finally came cleaning the block out and painting it ready for reassembly. practicalclassics@bauermedia. co.uk

Charles Tanner (left) and Simon asses the block at Beaulieu.

Many of the smaller parts were gently cleaned by hand.

Block with bores exposed – nothing too bad.

Big end shells cleaned and laid out for inspection.