Ariel Square Four

[RobW]

I recently acquired a 1959 Square 4.

It would leave an oil puddle when I first started it up. Not too much, and I ignored it. But after I replaced the original oil pump with a Morgo unit the puddle was much worse and could not be ignored. The oil was coming out of the breather tube near the chain.

The Morgo oil pump instructions mentioned an engine breather pipe but there was nun inside the timing chest of my Ariel. Just the oil breather stub up by the dynamo drive sprocket.

So I bent up a bit of 8mm SS tube to move the breathe inlet to somewhere less oil soaked and bent the end of the tube downwards in the hope that it would collect less oil.

So far, starting it up in the workshop, the bike does not drop a conspicuous amount of oil out of the breather tube now. A good run will be the real test.

Square 4

Original Square 4 breathe entry

New 8mm Breather Pipe

[Roger Gwynn]

I would ditch the oil cooler so that your engine will be less likely to overheat and your oil stands a chance of reaching working temperature. The engines tend to run too hot whereas the oil does not become hot enough. Cooling cool oil will not cool the engine!