You cannot just drain the rad, water will remain in the low points of the cooling passages in the block. You have to pull the two block drains (one on either side above the pan rails) in order to get all the water out.
Yeah, I know. I was being sarcastic, hence "draining the block"................ How else would you drain the block if you didn't pull the drain plugs in the block?! :blob:
Do people really think you "drain the block" by draining just the radiator?? :violent2:
The original poster of this thread put this in the "Racers Forum". Most racecars don't have anti-freeze in there cooling system. just water. If your at a race track and you blow a hose and wet down the track with anti-freeze in your car, well lets just say that wouldn't be good.
In my opinion, if you have a racecar with just water in it, it's way less work to just drain the block(pulling the block drain holes). If you have a street car that you occasionally bring to the track and have anti-freeze in it, sure just make sure the mixture is correct for the climate that you live in.