Quote:
Originally Posted by Billy Nees
The trouble with setting a specific # for valve springs in this day and age is that the cam manufacturers are building cams that a flat tappet lifter just can't follow even with the best springs! I believe that some of the really sharp Stocker engine builders are actually getting away from "square" cams and going back to "softer" lobes at least on the exhaust as they're finding they're "cleaning up" the intake charge by not bouncing the exhaust valve around on the seat. Think about what the "harmonics" of that exhaust valve bouncing on the seat is doing to the intake charge not to mention the cylinder pressure.
Another good reason for "softening" the lobe is simply to use less spring. Heavy springs just "tie up" horsepower that can't be used to accelerate the vehicle.
I guess where I'm going with this is that as much as I'd like to see a "valve spring spec" rule put in the book it would make a lot of cams in use today unuseable and I don't forsee any of todays Stocker engine builders or cam manufacturers lobbying for a rule that will make their stuff unuseable.
But these are just the ramblings of a bored, crazy old fool living on a hill in Pennsylvania.
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It might make some of the "square" cams unusable but a max spring pressure rule would put everyone in the same boat and keep more engines in one piece. Less chance for a broken bouncing valve destroying an engine and maybe less chance of being forced to run a diaper in the near future. Not only the "SQUARE" cams but what about some of the 55mm cams I have been hearing about in stock. I wouldnt think they would be legal but they are out there. Ramblings of an old retired foolish dumb tech guy living in the flat part of Florida.