Block Heaters and Winterizing questions...

RockGeek

Recruit
Joined
Nov 13, 2008
Messages
5
Hey Guys - I have been reading a bunch of these engine heater / winterizing forums and I have not seen any mention of freeze plug style block heaters. I have a Crownline 1995 Mercruiser 350 w/ a Bravo One. Does anyone know if this motor has the normal freeze plugs that an auto version would have? If so - can I not just use a $30-50 block heater for a Chevy 350?

I live in E. TN (rarely dips into the 20s deg F) and I usually get out at least once or twice a month in the winter. I plan on keeping my boat in a wet slip with power access. I also plan to drain the main plugs on each cold weather visit but would like a little extra protection. My other option it seems would be one of the Wolverine style silicone pad heaters. Has anyone used these on this style motor? If so - Which model / wattage and mount location?

Let me know what you guys think. Thanks for all the pros who take time to help the rest of us out!

Thanks!
RockGeek
therockgeek@excite.com
 

bomar76

Lieutenant Commander
Joined
Jun 27, 2002
Messages
1,963
Re: Block Heaters and Winterizing questions...

1. There are no Freeze Plugs on a SBC. Those are core plugs used in casting the block, nothing to do with freeze protection.
2. Core plags are the same size on all 350's, Marine are usually brass.
3. I think the whole plan is a really bad idea.
 

RockGeek

Recruit
Joined
Nov 13, 2008
Messages
5
Re: Block Heaters and Winterizing questions...

Hey Bomar - thanks for the input. Do you recommend any other methods for keeping the boat usable year round? I know there are quite a few people who keep their boats in wet slips through the winter in this area. Are they all just risking freeze damage?


Thanks,
RockGeek
 

JustJason

Vice Admiral
Joined
Aug 27, 2007
Messages
5,319
Re: Block Heaters and Winterizing questions...

Yep.... there's no such thing as a freeze plug.... that a common mis-used word.... and a common mis-used idea.
The only thing you really can do is to make sure you drain EVERYTHING after you go out every time.
If you really want to do a lot of winter boating, then converting the engine to closed cooling will help some, as it's less things to drain.
 

chiefalen

Captain
Joined
May 18, 2008
Messages
3,598
Re: Block Heaters and Winterizing questions...

There are heaters for the oil, you stick down the dipstick, had them in Alaska.

However you could keep your boat in a heated garage.

There are other ones do a search i posted on them a while back.

Good luck
 

bomar76

Lieutenant Commander
Joined
Jun 27, 2002
Messages
1,963
Re: Block Heaters and Winterizing questions...

Anything that relies on power is a bad idea.
Power goes off, and you are SOL.
Same goes with the heated building idea, power dependent.
As Jason says, drain it (doesn't really take that long)...the only safe way.
Engines and manifolds are expensive.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,464
Re: Block Heaters and Winterizing questions...

If so - can I not just use a $30-50 block heater for a Chevy 350?
I also plan to drain the main plugs on each cold weather visit but would like a little extra protection.

Ayuh,...

By their very nature, a coreplug mounted block heater Won't work that way...
They are Immersion heaters,... Without Water surrounding the element,...
As soon as you power it, It'll burn up,+ Quit...
 

J JACKSON

Petty Officer 2nd Class
Joined
Apr 7, 2008
Messages
180
Re: Block Heaters and Winterizing questions...

i use my boat in the winter i just pull the plugs in the manifolds, open the drains on the block and pull the hose off the power steering cooler after every trip i usually do it at the ramp so on the way home the movement may help it drain better.it only takes a few minutes
 

chiefalen

Captain
Joined
May 18, 2008
Messages
3,598
Re: Block Heaters and Winterizing questions...

I also drain it every time after i flush it. When it's cold outside.

I use the boat in saltwater.

Like Bondo says air can't freeze.

After 2-3 times i bet it won't take you 5 minutes.

I just leave the wrench on the boat with the plugs when i do it.

Takes maybe 5 minutes to put the plugs back.
 

mylesm260

Chief Petty Officer
Joined
Sep 13, 2007
Messages
444
Re: Block Heaters and Winterizing questions...

Ya, I'm going to echo what everybody's said

bad idea

A) the block heaters are designed to heat the coolant and have the coolant heat the the engine... Without the liquid thermal coupler, your block heater will likely heat up to the point where it blows.

B) Relying on electric heat to prevent your block from cracking is a bad idea. Power faillures happen and when they do, your screwed.


I had this thought process before, and what I wanted was a magnetic heater that was only about 30 watts. Then I was going to use a computer UPS aswell. 30 watts directly on the side of the block would buy you like a 10 degree cuision from freezing. And at only 30 watts, a halfway decent ups could buy you 5 hours at least of power should the power go out.


But.... that thought of "air can't freeze" really made that whole idea pointless, so I drained my block , and now there is nothing to worry about.
 

arks

Lieutenant Commander
Joined
Nov 7, 2002
Messages
1,929
Re: Block Heaters and Winterizing questions...

FWIW, I kept my boat in a wet slip the past 2 winters in northern Maryland. I wanted to have the ability to use her on nice days so I installed 2 marine bilge heaters (Boatsafe). After the first couple cold days, I got nervous and winterized anything containing water including the engines because, as Bomar pointed out, a power outage lasting more then a couple hours on a cold day could be very, very expensive.
Draining and re-winterizing isn't too difficult and definitely worth the time and cost compared to a new engine.
 

RockGeek

Recruit
Joined
Nov 13, 2008
Messages
5
Re: Block Heaters and Winterizing questions...

Thanks for putting up with the Newbie!

Ok - so no go on relying on a heater. I am certainly convinced of that. Can I do this drain procedure while in the water though? If the boat is in the water there is always going to be water in some part of the engine - right? Do I also not necessarily need to flush and fill with anti-freeze?
The whole idea is that I would like to leave the boat in the water and not have to haul it around or take up space in my driveway. Am I just going to have to forget about that at least for the winter months?


Thanks again for everyone's input. I do appreciate it.
 

mthieme

Captain
Joined
Oct 6, 2007
Messages
3,270
Re: Block Heaters and Winterizing questions...

A) the block heaters are designed to heat the coolant and have the coolant heat the the engine... Without the liquid thermal coupler, your block heater will likely heat up to the point where it blows.

They make block heaters with that much power?
 

bomar76

Lieutenant Commander
Joined
Jun 27, 2002
Messages
1,963
Re: Block Heaters and Winterizing questions...

Well, yeah...
As Bondo pointed out, they are just immersion heaters (like the element in your electric water heater) and no matter what the wattage, no water surrounding it, the elemnent burns up.
 

mylesm260

Chief Petty Officer
Joined
Sep 13, 2007
Messages
444
Re: Block Heaters and Winterizing questions...

Does anyone know of any lower wattage magnetic heaters? Like I was saying before... 30 watts is what I'm looking for....
 

RockGeek

Recruit
Joined
Nov 13, 2008
Messages
5
Re: Block Heaters and Winterizing questions...

Mylesm260 here is a glue on pad style - 25 watt. Are you thinking about similar marine applications? If so - they make these up to 1000 watt. I am thinking about adding one just for easier starts and to keep moisture down within the motor and engine compartment whether on or off the water. I don't have a garage big enough for my boat so there is always a little rain getting past the cover somewhere.

25 watt
http://www.amazon.com/Kats-24025-Watt-Universal-Heater/dp/B000I8XDBM/ref=pd_sbs_auto_3

For the larger wattage pads:
http://www.wolverineheater.com/products.shtml

A friend of mine has a large yacht and uses these on his engine blocks. Then again he has a lot larger engines, engine room, more insulation and a closed cooling system. I guess I was thinking there may be a similar solution for the smaller boater...


Thanks again for everyone's input.
 
Top