401 - Oil & water temperature gauges

[dave dale]

My advice, for what it is worth, is that the oil temperature gauge is very important. Bristol experts, including those who make a living repairing engines, will tell you that more 2 - litre Bristol engines are wrecked by drivers not waiting for the oil to warm up properly than any other reason as the oilways on this engine are quite narrow. Spencer Lane-Jones wrote an article to this effect in the BOC Bulletin some years ago. It is advised to never put an engine under load till the oil is warm. The 401 / 403 engines notoriously take a long time to warm up in winter partly because the sump is of alloy and is shallow, with a large surface area. I run my 403 with radiator blinds and a windshield on the sump in winter. Even with these aids I sometimes have to travel 20 miles on a cold day before the oil temperature gauge needle lifts off the stop. Use of the lower gears and restrained driving until the oil temperature reaches 50C will protect the engine. Dave Dale.