Auto Racing: White smoke only during after start-up, valve stem seals, cold air intake

Question
Hello Dan, Hope you can help me hear.

I have a 94 Honda Prelude, currently installed Cold air intake, header, straight pipe from the cat. new cams and adjustable cam gears. My problem is that after my car sits for like half a day then i start it up i get a cloud of white smoke. Durring normal operation everything is fine. Only during startup. This started when i installed my adjustable cam gears and set them up at 2degrees advance on exhaust side and intake side. Could that be why.

Answer
Hi Roy:

First, how much mileage is on the engine.  I would guess it's in the neighborhood of 70-80,000.  

The installation of new cams and cam gears should have nothing to do with the smoking problem. Just to be sure you should have a leak-down test performed. Any reputable race shop can do one for you and it's much more informative than a simple static compression check. The leak down will tell you if there is a valve leaking and which one, and/or if there is a problem with piston rings.

Now, for the answer from experience.  What's probably wrong is your valve stem seals have gotten old, and have started to leak a little motor oil into the intake ports after the car has been sitting for a while. If you're hanging with your buds, and it smokes when you start it up, it can be embarassing .  Just tell them it's a race trick, the seals have been removed to help lube the valves at high engine speeds.  That is exactly what we do with the high winding race engines I work with.

At any rate, it won't hurt anything, probably won't use any oil to speak of, and until the valves or piston rings themselves are worn out,  the car will run fine.

I hope that answers your concerns. Good luck.

Dan Liddy
Sarasota, Florida