While autocrossing this weekend the engine just belched clouds of oil smoke after two very hard turns. It happened in both of my last two runs. At each turn, I first slowed with the brakes, then downshifted to first and then turned and accelerated, all within two or three seconds. None of the shifts resulted in an overrev as I went one or two gates after the turn before shifting to second without hitting the rev limiter. I drove the car 200 miles after the race and have noticed no ill effects.

An experienced S2000 racer told me it was the engine oil being forced into a bypass valve and not to worry about it. This makes some sense, especially since my oil level was a little above the high mark. I just don't understand how the bypass velve works and how it allows oil into the combustion chambers.

Anyway, has this happened to anyone else?

 

It's very common. Sometimes we have to educate the corner workers here in Cali not to black flag us for it!

 

Thanks Strike. That is very reassuring. Do I need to do any maintenance after this episode like clean the plugs or clean the by-pass valve?

 

Nope. The oil gets burned up which is where the smoke comes from.

 

It was a right hand corner wasn't it?

 

You can get an oil catch can setup that will keep the oil from going back into the intake manifold and gumming up your throttle body and intake. There is a thread in under the hood about this and it's pretty current.

 

krazik...right you are. And this was the first time I ever bothered to downshift to first with this car at an autocross, which really helped my times as the car gets around tight corners much faster in first than in second...hence the higher Gs and the smoke I guess.

cthree, thanks. I'll look for that in under the hood. There was a picture posted there in my other thread that showed the set-op. Krazik said the guy had catch-canned the wrong line. (too bad, as it was a very nice job.) Which one is it?

 

Only happened to me once, but it was TWS #3 which is a hard right.. and I did get black flagged.

 

I got black flagged for this at TMS. I found that it happened only if I didn't rev match on the downshift in a hard right-hander. I assumed that downshifting without giving it throttle creates much more vacuum in the manifold.

 

Like strike said, at speed ventures we make a habit of telling the corner workers in the morning, to not worry about smoking S2000s.

It happens to a lot of s2ks on some of the CA tracks.