I have a question? I have a friend (i know hard to believe). He has a fountain. He sent his boat up north months back. On the way up the transporter ran into a snow storm. The temp dropped to 30 degrees. the transporter pulled over, dumped a few gallons of antifreeze into each sea strainer and cranked the motors. Never strarted them! Got back n the road, drove about 5 hours to the destination where supposably the boat was put inside a heated warehouse. Long story short, now both blocks and 2 heads are cracked. Because the motors were never started and the thermostats never opened the blocks were full of water. My question is, could they have frozen that bad in that short of time in those just below freezing temps while in transport. My opinion is no friggen way, the boat had to be left outside for a period of time in colder temp to do that kind of damage.
This is a huge problem, we need expert advice. We all know how may experts we have on OSO!!

I have a customer who had one block and one manifold crack in Las Vegas the temps were around 30 and thats all it took. The weird thing is the bolck and the manifold cracked on one engine and no damage at all to the other. But if you were driving or sitting still I don't think its matters cold is still cold. I'm not sure how long it would take for them to crack but I would guess 4 hrs?

At 30 degrees? Not buying it. You said it, long term, way deep temps.

But I'm from Phoenix where "winterizing" a boat means wearing a sweatshirt to the lake when you go in January.

I look at it this way. 30 s just freezing. It takes ice cubes a couple of hours to freeze. I would think the boat and the steel blocks would be some sort of insulation and the water in the block would take some time to freeze solid enough to expand and do all that damage.

I would have to say that there is no way that 30 degrees for 4 hours would do it. The antifreeze in the strainers didn't do anything as if he just cranked it would not been enough to fill the block or manifolds. It may have shown good faith but that's about it as it would provide no benefit.

Unfortunately...I'm no expert

at 30 not happening in 4 hrs boat insulate the engine that boat sat ouside alot longer than that i live in wisconson and it takes alot more than that i gaurentee that !

Gino Thats seems hard to believe. It usually has to get down in the 20s for a extended period to crack a block. I towed my new boat home in April and we had a freak spring snow storm here and i didn't even put my boat inside my storage building. I think theres more to this story Here's some pics. of mine on April 7th I didn't even drain the water tank!!!

I ran a heater in my bilge here in DC all winter and would always check my bottled water in the truck in the morning. A botle of water wouldn't freeze overnight until it got low 20's or high teens. Usually parked at 6 and started back up around 9....nothing ever froze even in the mid 20's for 9 hours....

It would take a hard freeze of about 20 degrees for a day. 30 degrees would not do it for 4 hours. More to this story I bet.

Around here guys still have their boats in water for striper season when the temps are getting that low overnight.

I don't buy it.