Let's hear about what some of you guys have rigged up to keep those big blocks toasty I plan on winterizing the boat this week end with pink -50 antifreeze but was going to add a heating element for some added piece of mind

I find that air is great at not freezing in the cooling passages of my engine.

in 15 years ive winterized 1000 s of boats with -50 below pink and they all sat outside never a problem ,I see no need to do anything else
unless your in Alaska .the worst the pink stuff does at - 30 is get slushy .id be more worried if you put a heater or a light bulb in it all winter

Use better protection and don't worry about heating it. You'll sleep better.

60 watt light bulb hung in between the engines.

I bet you live where it gets cold. Asked a guy 15 years ago from Alaska what they did and all he said was, "air don't freeze". Stabal in the gas tank, flush it, fog it, drain it, done

Do Not Add Heat........The cool Metal Engine and Warm air will make Condensation, Everything will Rust, Even if its painted or coated, Trust Me.... I have used Light bulbs & Heaters..Just use Anti-Freeze or drain everything..

I'm having difficulty locating my port side block plugs on both motors. This weekend it's suppose to get below freezing for 2 nights. In case I don't get my winterization done before should I throw a light in at night or will it take more then just 2 nights dipping below 32 degrees.

I've been to more house fires caused by heating elements and lights than just about anything else. Make sure your insurance is up to date

depends on the sun and daytime temps.quick answer,you'll be fine.alot of mass to cool.