Posted by Chriscase @ San Diego on Friday, January 18, 2008 at 10:12:25 :
In Reply to: Re: No. Pumps make pressure. They push water into the block. posted by Tim Holloway on Friday, January 18, 2008 at 06:58:55 :
You have a pump forcing water into the block. The block has a restriction when the thermostat is closed. Completely. The open thermostat is still an appreciable restriction. "Block Pressure" is known. That is why racers who don't run thermostats us thermostat eliminator plates. Different size holes in them for different needs.
I know they do. Yesterday I watched my leaky freeze plug. It dribbled with the engine off, squirted with it running.
I just tried googling for <'block pressure' thermostat>. Found several discussions, with quotes of from 30 to 60 psi in sbc's with various pumps. Plus some talk about screw in freeze plugs. And how steam pockets will make cavitation holes in cylinders.
Got to go now, need to dig through my plumbing fittings.