I read that the 4 valve relief 'eyebrows' of a stock 273/318 piston were a given 7cc's of lost compression when doing calculations. Im here to debunk it: I took some modeling clay and filled one of the reliefs of a stock 273 piston them rolled a deep socket over it to make sure it was nice and filled. I then cut the excess off and was left with a totally flush piston top in that area. I pealed the clay out and dropped it in a 10ml syringe filled with 5ml of water. It displaced exactly .6ml...
The 7cc myth.....
