A few Technical points

by John Winn

Well we thought the French loved Merlins last year when we toured the Loire valley but the Spanish are even more enthusiastic. We spent three weeks in late August early September touring the North coast of Spain from Santander (ferry from Plymouth) to Ribadeo about 180 miles to the west. This coast has a mountain range running parallel to it only a few miles inland with magnificent scenery , challenging roads running through narrow gorges and good walking.

The beaches are superb with golden sands and the tide goes out a long way creating huge areas, so there is little crowding. However the beaches only occur at intervals in an otherwise rocky coastline so it is a case of reading the maps an tourist books to locate them. We stayed at nine different hotels dividing our time between the mountains and the beaches, usually in villages and two star rating. Wherever we parked people came to look at the car, sometimes to be photographed by it, and often asking what it was, but it was always respected and not handled. On the roads we were waved at, hooted and flashed and given big smiles -the car was a great passport to having a super time. We did about 1400 miles in total, just over 900 miles in Spain. The roads were generally quite good, not as bumpy as I had anticipated -and the car performed perfectly.

As usual a few technical points arose in preparing for and during the trip, some specific to the Sierra Merlin but not all:-

Trip Preparation

Hose:- I put the whole car up on ramps to check underneath and found a hose was crazed where it went onto the radiator's top-up inlet which is difficult to get at. I struggled to get it off and after half an hour, even with washing up liquid, I had failed to refit the replacement. I then remembered an old tip and soaked then massaged the new hose end in hot water. It softened and went on easily.

Steering column:- When I built the car the steering, with its universal linkages, nearly locked during its first trial run. The grubscrew was not tight enough to prevent the outer triangular sheath from moving on the inner shaft from the steeling wheel, with the consequence that the sheath slipped downwards and put excessive angles on the linkages. I have regularly checked the grubscrew since then. However when I considered mountain roads twisting and turning (and they certainly did) I decided to fit a safety pin. A bit difficult but with a rechargeable drill and later with a flexidrive chuck I drilled through the outer sheath and well into ( but not through) the shaft, then inserted a pin made from a large nail ( using just the head and enough length to suit), clamping the pin in place with a small jubilee clip. A touch of black Hammerite made the arrangement look acceptable.

I have since rechecked the grubscrew and it stayed tight but I am still pleased to have eliminated a possible "incident".

During the Trip

Fuel expansion:- Often in Spain the garages do the petrol filling with a tendency to fill not only the tank but most of the neck tube, which I try to avoid. After such a fill up we travelled fifteen miles to our hotel and parked. Next day was very hot and in the afternoon we decided to use the car only to find it had dripped petrol down the side of the tank and onto the tarmac. When I undid the petrol cap the petrol was brimming out of the filler neck. At a conservative estimate the petrol, presumably cool from a deep tank at the garage, must have expanded by more than three pints! I was amazed, also relieved as my first thought was that the float mechanism gasket on the tan end had sprung a leak which, adjacent to the exhaust pipe ( with the carburettored engine not Fuel Injection) is. To say the least, not desirable.

Cooling:- Not the most efficient in the Sierra -build with its sloping radiator. However there were no problems - even during a 10 mile climb from sea -level to over 3,000 feet in third gear with short spells in second gear the electric fan only cut in twice, towards the end. Running an tickover remained smooth, and although my engine -bay fan (see July ,98 newsletter) ran a few times standstill ( cuts in at 60 degrees C) I now think it may be unnecessary except perhaps in extreme conditions. I do think, however that blanking off the gap above the radiator and the small air scoop I fitted at the bottom when building the car, to maximise airflow through the radiator core, are beneficial as the electric fan very rarely operated except in slow town traffic. The ambient temperatures were often over 75 degrees F, sometimes over 80 degrees F .