Wikipedia strikes again.... Not a myth, seen it happen. And even IF radiato= r takes hit, it's a few hundred to repair vs cracked block thousands. B= esides, the block is cast and inflexible with some relatively large water a= reas (more expansion) vs radiator with small tubes (less expansion) and mad= e of brass or aluminum (will expand and stretch some). As for a solution, given the OP's requirements, just wire in a switch to di= sconnect the brake light switch. Unless its antique vintage, there's a buil= t in interlock to prevent coming out of park if it's an automatic if the br= ake isn't depressed. Engine runs but you'll catch the guy sitting in your c= ar trying to put it in drive.... Just walk out and point gun... And it's simple enough as you may be able to reach under and just pull the = connector off the brake switch when you need to implement. No wiring or pro= gramming needed. And no suspicion of a trap.... --=20 Sent from my Android=20 David C Brown wrote: >I did once have a core plug popped due to the water jacket freezing >when I >forgot to check the anti-freeze. The mechanic who repaired it for me >acted >as if that was a fairly normal occurance > >On 22 November 2014 at 16:15, Joe Wronski >wrote: > >> That caused me to go to wikipedia, which calls freeze protection a >myth. >> >> >> Now that I think of it, I had and heard of cases where coolant >blockage >> from freezing causes overheating, but never that someone needed to >> replace the plugs because they did their job. Rusted out, but not >> popped due to freezing. >> >> Joe W >> >> >> On 11/22/2014 3:51 AM, Justin Richards wrote: >> > Thanks rich, >> > >> > I can imagine from your explaination that there's many stories of >people >> > driving of without unplugging first. >> > >> > And wrt the plugs I take it from the description it is what I know >as a >> > welch or core plug that are used to plug the holes that the >moulding sand >> > is poured out of. >> > >> > Cheers Justin >> > >> >> There is another type that is inserted in to the engine >block in >> >> place of what we Americans call a freeze plug. I believe you folks >call >> >> it a soft plug. Again you plug it in at night and it will keep the >> >> coolant at about freezing in 30 or 40 degree f below zero >temperatures. >> >> >> >> >> -- >> Joe Wronski >> jwronski@stillwatereng.net >> www.stillwatereng.net >> >> -- >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> > > > >--=20 >__________________________________________ >David C Brown >43 Bings Road >Whaley Bridge >High Peak Phone: 01663 733236 >Derbyshire eMail: dcb.home@gmail.com >SK23 7ND web: www.bings-knowle.co.uk/dcb > >--=20 >http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >View/change your membership options at >http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .