What cold temp will result in a boats engine block cracking?

Answer 1

Yes! If it gets to below freezing. Even a small amount of water left in the engine can freeze and cause big damage. Inboards and sterndrives require refilling with propylene glycol antifreeze to prevent small ice pockets from forming, which can crack the block. Water left in the engine will freeze and expand...the metal and alloys surrounding it are forced outward by the expansion...causing damage, such as cracks. Expensive fix.
You might want to check out.

http://www.popularmechanics.com/outdoors/boating/1276866.html?page=1

which has a good article on winterizing your boat. Boats arent cheap, take time to protect your investment.

Answer 2

32 degrees outside will not crack the block, especially in a boat. The water around the boat is not frozen so it is keeping the inside warmer. When it gets downto 20 for an extended perion we leave a heater on that turns on at 38 degrees. Others have said a couple light bulbs lit will do it. We leave our boat in the water for the winter in MD. It has frozen in, but for a sail boat hull, all it did was scratch off some bottom paint as the tide went up and down. We do winterize the water systems, For the engine we disconnect the water intake and put the hose in the antifreeze and another hose for the return into a bucket and run the engine til the thermostat opens. We do this when days are staying at 30.and nights in the 20's We still run the heater all winter.

Answer 3

Any temperature below 32 degrees F can crack a engine block. You'll need to winterize your boat if your temps fall below that in the winter. A mechanic will remove all the water and oil from your boat and add fresh oil to prevent it from cracking the block.

Answer 4

Most outboard engines are fitted with a Frost Plug which is mounted on the powerhead and made of aluminum and will burst before the block cracks in very low temperatures. Providing you drain the water by tilting the engine prior to removal, you will have little problem.

Answer 5

There are many variables. Carport? Cover? Duration of exposure? Thirty-two degrees (0 degrees Celsius) can freeze the water and crack your block, if exposed to that temperature long enough. At 10 degrees Fahrenheit, the water would freeze faster and the block could crack faster. Don't be lazy and sorry...it takes about 1/2 of an hour, and about $10.00 in supplies.

Answer 6

anything below 32*F, if it's a "car" type motor store with anti-freeze, if it's an outboard engine, drain the heads after fogging and flushing the motor, by leaving the motor tilted in the "Running" position on the transom when finished.

Answer 7

if you don't winterize/antifreeze the block anything below 32 or less will freeze the block and crack.