Valve springs

So the boards have been really slow lately so in an effort to liven things up a bit, I thought I'd post up something that's been on my mind lately. The other day at work while timing an engine, I was remembering a report we did while in UTI about camless technology. The best theory would be to use a electronic solenoid to actuate the valve but that can be unreliable to activate and deactivate that many times(at 7000 rpms it would need to activate 58 times/sec) and the solenoid would never fully deactivate and the valve would probably hang open. But in a low revving diesel this technology is a reality, I believe it was International who used this in an engine they built for some kind of rally.

Anyway back to the main point, the biggest advantage to this technology it the obvious considerably less drag on the engine so it should free up a ton of power. Ever try to turn over a DOHC engine? Now take the timing belt(or chain for you nissan guys) and turn it over, turns alot easier doesn't it? But that got me to thinking, do heavier valve springs create more drag and therefore rob more power? Essensially, what I was thinking was if you install heavy duty valve springs in an engine and don't change anything else, do you think you would lose power?