Friday 21 June 2024


 Welcome to the boring world of Positive Crankcase Ventillation systems. Little did I know that on modern (post 1960's) cars, they connect the crankcase to the inlet manifold so that blowby doesn't pressurise the crankcase, and so that the blowby and the oil mist get burned in the engine. Damn Los Angeles and their smog problem!

I took my sports car to Snetterton last week and had a miserable time. I got black flagged twice for making excessive smoke. So much in fact that people came out on to the pit wall to gawp and speculate. While we did get to do some high speed driving (after the oil level had dropped), and engine ran pretty well it used A LOT of fuel.

I have since done a compression test and the engine looks a bit worn, but not catastrophically so. This is my best guess about what went wrong: The engine is just a bit more worn out than it was the last time I used it. The oil was topped up right to the top. There's a long right hand corner which pushed the oil up towards the PCV system. This combination of factors overwhelmed the PCV system and pulled a load of oil into the inlet tract and we burned it whenever we opened the throttle wide. The soot has messed up the lambda sensor in the exhaust, and it's now overfuelling wildly. The engine is already out of the sports car and in the back of the Fiat Panda waiting to go down to the engine builders.

I record this here just for the next time I have to do it: It takes more than a day, but less than two days to take the engine out of my Caterham. You have to have three people present when you crane it out. I know we've all seen Ed China do it with one assistant, but I simply cannot replicate that.

Richard "Catch Tank" B

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